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Dan
Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 5129
Experience:  17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
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I have a cattapillar 950 F loader with serial#8tk01717 that

Customer Question

I have a cattapillar 950 F loader with serial#8tk01717 that will not go into 4th gear?
Submitted: 1 year ago.
Category: Construction and Road Equipment
Expert:  Dan replied 1 year ago.

HYi my name is***** will be glad to help. Check the oil level and condition for signs of friction material and metal in the filter or strainer indicating internal problems requiring rebuild. If clean, check for power in and out of all gear positions to the transmission solenoids including 4th gear.... If there is power there try swapping solenoids to see if the problem moves with it. Let me know

Customer: replied 1 year ago.
Tried all that so far last time talking to you. It is a 24v system though what voltage should I get at solenoid plug?
Customer: replied 1 year ago.
No debris in filter housing and fluid looks good just quite a bit overfilled
Expert:  Dan replied 1 year ago.

I just tried looking at our old conversation and it has been deleted by the site.... Please refresh my memory of the tests you have done and the results... Are there any solenoids not getting power at the transmission in 4th? and if not and the shift controller tests good then what happens when swapping solenoids? will the problem move to another gear? If it remains the same the next step is to test your pressures and see what 4th gear is doing as if pressure drops off in that clutch it means the clutch pack has a problem and the transmission needs to be taken apart.

Customer: replied 1 year ago.
Ok can you refresh my memory on how to test the power at solenoids from switch?
Customer: replied 1 year ago.
Let's just start from scratch but I told you it was 12v system when it's 24v
Expert:  Dan replied 1 year ago.

What voltage are you getting to the solenoids that are working and shifting properly?

Expert:  Dan replied 1 year ago.

The schematic I have shows 12V for the transmission solenoids and it is a 24V system

Expert:  Dan replied 1 year ago.

Click here.

Schematic

Expert:  Dan replied 1 year ago.

This info will likely be helpful too for test purposes.

Testing

Customer: replied 1 year ago.
Has 12.4 v and like flames back and fourth to o.2 ground reference at solenoids
Expert:  Dan replied 1 year ago.

What do you mean by flames back and forth? 12.4 V is what should be there to engage the solenoid... If you have that then try swapping solenoids with another gear. Also 4th gear solenoid should be powered in Neutral. If not check the harness and the shift controller for worn contacts...

Customer: replied 1 year ago.
Sorry dang auto correct it has 4.57 volts with v meter now and stayed
Customer: replied 1 year ago.
Checking wiring now
Expert:  Dan replied 1 year ago.

Here is the chart for what solenoids will be powered in each gear selection

Expert:  Dan replied 1 year ago.

Transmission Solenoid Location ( Description for picture)
(1) Solenoid 1 - Reverse. (2) Solenoid 2 - Forward. (3) Solenoid 3 - Gear 4. (4) Solenoid 4 - Gear 3. (5) Solenoid 5 - Gear 2. (6) Solenoid 6 - Gear 1.

Customer: replied 1 year ago.
Ok so I don't have full 12 volts going to forward and 4th solenoid. Has it for split second when first shift it but that's it.
Expert:  Dan replied 1 year ago.

Thanks for the update. But you have it in all other gears. this points to a faulty shift controller. Test for power right out of the shifter in 4th and if it does the same right at the shifter, the shifter is no good

Customer: replied 1 year ago.
Ok was checking power right out of shifter and didn't have power but now has no gears and won't start all the sudden? Like neutral safety? How to check control switch?
Customer: replied 1 year ago.
Wiring diagram from switch would be awsome!
Expert:  Dan replied 1 year ago.

Hi, Thanks for the info... If you have power into the shifter and now nothing coming out in each gear position replace the faulty shifter. That means the shifter is bad. It is a common wear item.... If the contacts wear and now is not reading neutral position it will have the symptoms you are experiencing. Power in but not out in all gear positions means a bad shift controller.

Customer: replied 1 year ago.
Have 2 wires with 12 volts going in to shifter and nothing out
Expert:  Dan replied 1 year ago.

You have a bad shifter my friend. Replace it and you will be all set.

Customer: replied 1 year ago.
Ok replaced shifrer. Starts now but does not have second. Stays in 1st when shift selector to 2nd and still shows first on display. Still no 4th gear either.
Expert:  Dan replied 1 year ago.

You got forward and reverse 1? Swap solenoid 6 with solenoid 4 and let me know what you get for results

Customer: replied 1 year ago.
forward and reverse 1st switch solenoids and same issue
Expert:  Dan replied 1 year ago.

If you have power to your solenoids and swapping the solenoids has no change it leads to internal mechanical problems in the transmission or control valve itself. Pressure testing the transmission and comparing the results to specs is your next step. This will tell us if you are losing pressure from a valve problem or a clutch leaking internally, etc.

Expert:  Dan replied 1 year ago.

No metal or clutch material in the filter or suction screen? You mentioned the level is overfull or is it continuously overfilling from a hydraulic pump seal leaking into the transmission?

Customer: replied 1 year ago.
No debris in transmission. If I hit forward solenoid and 4th gear solenoid with 12v it shifts into 4th and works?
Customer: replied 1 year ago.
Gotta be wiring or something right? I'm checking wiring and stuff right now but tried putting 12v just to see if it would work and it does. It doesn't have 12v at solenoid.
Expert:  Dan replied 1 year ago.

Take a close look at the harness between the shiftter and the transmission solenoids for any shorts , corrosion or damage and if ok also take a look at the transmission neutralizer circuit and switches/harness for damage or proper operation. Theis will put the transmission in neutral when the left brake is pressed or the button is pushed which I believe is usually on the bucket control lever. Let me know

Customer: replied 1 year ago.
Wiring from transmission to duesh plug going through cab is good but from the two control switch plugs to the dueshe plug can't ohm out. Gives me weird readings? Is there something else that should be unhooked when testing wires indavidually?
Customer: replied 1 year ago.
Could it be the autoshift controler
Expert:  Dan replied 1 year ago.

It very well could be the controller. Ill try to dig through my files later to see if I have any schematics. Click on the link for the pressure tests.....

Pressure testing

Expert:  Dan replied 1 year ago.

Click on this link.

Troubloeshooting

Customer: replied 1 year ago.
Ok have ohmed all wiring from switch to auto shift module to solenoids and all is good.
Customer: replied 1 year ago.
Ok everything is good now shows right gears in display and all solenoids have right voltage expect in 4th. Neither forward or 4th gear solenoid have power when switched to 4th gear?
Expert:  Dan replied 1 year ago.

What changed to make that happen? Did you find wiring trouble?

Customer: replied 1 year ago.
No disconnected everything and hooked back up. That's it.
Customer: replied 1 year ago.
Just disconnected everything and hooked back up.
Customer: replied 1 year ago.
Computer problems maybe or what could cause that gear only not to work?
Expert:  Dan replied 1 year ago.

Run a test harness from the shift control to the solenoids for 4th and if it works there is a problem in the harness wiring or connector pins

Expert:  Dan replied 1 year ago.

click on this link

ECM pinouts

Expert:  Dan replied 1 year ago.

Some of the returns will be shared as shown in the diagram ( White 975)

Customer: replied 1 year ago.
K will check it a little more tomorrow and let you know
Customer: replied 1 year ago.
Thank you very much
Expert:  Dan replied 1 year ago.

Pleasure to help.

Customer: replied 1 year ago.
Ok have good ground from switch to ecm on 966 gray wire while in 4th. No power out to solenoid 4 on 754 blue wire. Or am I reading these pin outs wrong haha
Customer: replied 1 year ago.
The switch is what grounds the ecm to send power and it's not sending it so computers bad?
Expert:  Dan replied 1 year ago.

All forward gears use solenoid 2.... forward and 4th uses solenoid number 2 an 3 so check solenoid 3 on the diagram (The solenoid chart) solenoid 3 should have power and if it does in 4th then swap 3 with one of the others and check if the problem moves. 4th gear is the only gear that uses solenoid #3.

Expert:  Dan replied 1 year ago.

I am heading out for a family gathering and will not be back until late tonight but check the solenoid location diagram and remember 2 is forward and 2 and 3 powered is forward and 4th

Customer: replied 1 year ago.
I have checked that. When switched to 4th it doesn't have power at forward or 4th solenoid.
Expert:  Dan replied 1 year ago.

Interesting... Can you do something for me? In each gear position let me know what solenoids are actually getting power according to the chart and if 4th is the only one with any type of power loss to any of the solenoids or are there any others in the other gear positions?

Customer: replied 1 year ago.
Everything is good all forward gears have #2 solenoid like you mentioned but as soon as I switch it to 4th gear solenoid #2 or #3 have power like suppose to.
Customer: replied 1 year ago.
Have no power*
Expert:  Dan replied 1 year ago.

Interesting. Do you have access to a laptop with CAT ET to read live data? Is the fault warning indicator going off when this happens?It looks like a faulty ECM I would try having your reflashed with the most current software version and the calibrations done with ET and see if the problem still exists.

Customer: replied 1 year ago.
Does it need to be on unit when reflashed?
Expert:  Dan replied 1 year ago.

Depends on your dealer. the dealer i worked for had test bench harnesses

Customer: replied 1 year ago.
K do you have a flash code description because it does have codes.?
Expert:  Dan replied 1 year ago.

What codes are you getting?

Customer: replied 1 year ago.
I have a big list but not on me. None active though
Expert:  Dan replied 1 year ago.

could you post them when you get a chance?

Customer: replied 1 year ago.
sir tomorrow morning
Expert:  Dan replied 1 year ago.

Sounds good

Customer: replied 1 year ago.
Ok 4th gear still never worked. Now 2nd gear doesn't work but is intermittent. Sometimes it does. But while loading the bucket and driving it its like it looses power. Won't even scoop scoop loose dirt up hardly?
Expert:  Dan replied 1 year ago.

What were the results when monitoring with Cat ET as I suggested? How dis the re-flashing go of the ECU/ECM? I would have the module reflashed for a complete reset and update to new factory settings then see if the problem still exists.

Customer: replied 1 year ago.
Haven't done that yet but will but low power problem won't be ecm will it? And can I just take ecm to dealer for reflashed or whole unit?
Expert:  Dan replied 1 year ago.

That will depend on your dealer if they have the test harness to do it on the bench. Some do. If not they will need to access the machine by Field service or bring it to them. Call ahead and maybe your dealer has the test harnesses on site. The dealer I worked for did. Pull the hydraulic filter and trans filter again and cut them open to inspect a sample. Squeeze the excess oil out in a vice. any fine metal/debris indicates a component failure occurring.

Customer: replied 1 year ago.
Ok will do
Expert:  Dan replied 1 year ago.

Pleasure to help

Expert:  Dan replied 1 year ago.

Keep me posted and remember to rate my answers once you have all the information you need as that is how the site credits the experts for their time on the site.

Customer: replied 1 year ago.
Sure will. If fluid and filters look good what do I check next for low power? It won't drive if in a pot hole or won't even back drag anything. In first gear or any
Expert:  Dan replied 1 year ago.

Start with your engine fuel system checks for restrictions and leaks or low fuel pressure, etc., turbo and air system restrictions or problems and if the engine checks ok it is time to get some test gauges on the converter and transmission to run through the pressure tests.

Customer: replied 1 year ago.
Engine is fine it's like fluid us bypassing somewhere. Weak pump or seals or bushings bad but no degrees in fluid
Expert:  Dan replied 1 year ago.

It is time to get test gauges on this and have the pressures checked and conformed to specs.

Customer: replied 1 year ago.
Drained tranny again. This time it has like fine green pieces of seal or something in it. What should I be looking for exactly?
Expert:  Dan replied 1 year ago.

thanks for the update Cut open with a non abrasive cutting tool or filter cutter the filter and after cutting a decent size sample of the filter element, squeeze the excess oil out in a vice. then open up the sample to see what you find for metal, o ring/seal material, clutch/friction material, etc. This will flag an internal problem.

Customer: replied 1 year ago.
Ok had some like red fuz in filter like a red rag coming apart or something. Supposedly transmission was just rebuilt about a year ago. Not any hunks of nothing really. Some fine metal flakes not very much though. And what type of fluid does transmission take. Thank you
Expert:  Dan replied 1 year ago.

Byi chance can you take a photo of the debris and metal? When these components fail it starts as fine metal flakes looking like glitter in the oil. These flakes get caught in the filter which helps tell us a story. aluminum ( Converter), steel/brass ( Pump Hyd system). Having your pressures checked will confirm an internal problem if the pressure is dropping off in 4th gear. Transmission and Drive Train Oil or equivalent. Most auto parts stores have their version of this. Make sure it meets the Cat Spec for wet brake systems.

Customer: replied 1 year ago.
Says file is too large?
Expert:  Dan replied 1 year ago.

Did you take it from your cell?

Customer: replied 1 year ago.
sir
Expert:  Dan replied 1 year ago.

Try uploading to mediafire.com or dropbox.com and share the link with me or I can send an additional service offer where I can offer my e mail to send it to

Customer: replied 1 year ago.
http://www.mediafire.com/view/k5hz7b15dgz7dd9sysca5
Expert:  Dan replied 1 year ago.

i got an error message.

Invalid or Deleted File.

The key you provided for file access was invalid. This is usually caused because the file is no longer stored on MediaFire. This occurs when the file is removed by the originating user or MediaFire.

Still have questions, or think we've made a mistake? Please contact support for further assistance.

Customer: replied 1 year ago.
303 hydraulic fluid right?
Expert:  Dan replied 1 year ago.

No.Cat TDTO SAE 30 is

factory

fill

for

standard

configuratio

n

Medium

Wheel

Loaders

(950-980)

and

Medium

Wheel

Dozer

(824)

Except

for

machines

that

are

equipped

with

a

hydraulic

drive

winch

gear

case.

Use

SAE

30

viscosity

grade

for

0°C

(

32°F

)

to

43°C

(

1

10°F

)

or

Cat

TDTO-TMS

for

−20°C

(

-4°F

)

to

50°C

(

122°F

)

.

When

you

are

operating

the

machine

in

temperatures

below

−20°C

(

−4°F

)

,

refer

to

Special

Publication

,

SEBU5898

,

Cold

Weather

Recommendatio

ns.

This

publication

is

available

from

your

Cat

dealer

.

Expert:  Dan replied 1 year ago.

TO4 spec

Click here for the specs.... Match the specs or go with Cat OEM oil.

http://www.toromontcat.com/pdf/transmissionsynthetic.pdf

Customer: replied 1 year ago.
Thank you. Where are all the filters at that I need to check?
Expert:  Dan replied 1 year ago.

The transmission filter will be under the step platform and the suction screen at the bottom of the case. Please remember to rate my answers.

Expert:  Dan replied 1 year ago.

Let me know if you need more help

Customer: replied 1 year ago.
Removed back cover off of transmission at bottom and can't find any bad looking debris. Everything looks pretty good except for that fine fine metal which I would call normal wear in a semi. Because wasn't much of it.
Customer: replied 1 year ago.
Suction screen where on bottom of case? And filter is the cartridge filter under cab?
Expert:  Dan replied 1 year ago.

Thanks for the update. Truck transmissions and wheel loader transmissions are two totally different animals. Your transmission has clutch packs and planetaries as well as a valve body, o ring seals, and functions off of hydraulic pressure the same as an automatic transmission. If your comparison is to debris found in an Allison automatic, it would be a more equal comparison but an Eaton or Mack transmission is mechanical and air and electric solenoid shifted for the autoshifts. Gearbox transmissions are more forgiving of debris and contamination.

Expert:  Dan replied 1 year ago.

On the bottom of the Case look for a square cover with 4 bolts. The screen is inside there.

Expert:  Dan replied 1 year ago.

Click this link. The next step is to test your pressures.

Pressure test

Customer: replied 1 year ago.
Thank you very much. And yes sir I've found more debris changing filter on an Allison than this and worked fine still that's why I mentioned it. I appreciate your help. I'm gonna pull screen and check it
Expert:  Dan replied 1 year ago.

Pleasure to help. All it would take is a leaking seal in the 4th gear clutch pack for pressure to drop off and not apply those clutches. Testing the pressures will tell if you have a loss of pressure in 4th from internal leakage, etc.

Customer: replied 1 year ago.
It don't drive in any gear when loading dirt it just looses it's power to drive. I got 4th gear working. The solenoid wasn't getting power.
Expert:  Dan replied 1 year ago.

Sounds like a pump/Converter problem. You need to test your pressures as the next step.

Customer: replied 1 year ago.
On tap (E) for pump is suppose to be 310 psi at idle. Is that with axles in or out?
Expert:  Dan replied 1 year ago.

At all times engine running....

Expert:  Dan replied 1 year ago.

the chart will tell you if you need to be in gear, at idle, or full RPM

Expert:  Dan replied 1 year ago.

When you lose pressure the first to always go is lube which is everything left over and is non adjustable. There is no need to adjust anything and do not try or it will complicate the troubleshooting procedure. The machine worked with the existing shims, etc. There is another issue not related to the adjustments. And trying to shim or adjust to compensate for the actual problem is a waste of time and will just be a waste of time and make it tougher to test and analyze the test results. See that you have for lube, converter in and out, then clutches.... Let me know the results for each

Customer: replied 1 year ago.
On tap (E) for oil pump it only has 75 psi at idle and don't go over 150 at high idle.
Customer: replied 1 year ago.
Pump bad or do I need to check converter still?
Expert:  Dan replied 1 year ago.

Bad pump. If you did not have aluminum, friction material, or metal in the filter or suction screen change the pump and then reconfirm your pressures and run through the tests. No reason to go further with low pump output.

Customer: replied 1 year ago.
Pumps is on top side of transmission correct? Removal procedure by any chance. Thanks for all your help buddy much appreciated.
Customer: replied 1 year ago.
should I check anything else before I change that jewel?
Expert:  Dan replied 1 year ago.

Yes, Remove the covers under the cab to access the hydraulic pump. Drain the hydraulic system oil, Remove the hydraulic pump lines and mounting bolts and remove the pump. Unbolt the transmission charge pump and remove. Clean all sealing surfaces and reinstall both pumps with new o rings installed lubricated with grease.

Customer: replied 1 year ago.
Ok so need both pumps or just transmission charge pump? And drain transmission oil and hydralic tank or just hydralic fluid tank? Thank you
Expert:  Dan replied 1 year ago.

Just the transmission pump unless you are losing hydraulic oil into the transmission and overfilling from a faulty hyd pump seal. If not the hydraulic pump just needs to be removed to get to the charge pump

Expert:  Dan replied 1 year ago.

Be sure to get all new o rings to mount and seal it and for the lines. Both hydraulic and charge pump.

Expert:  Dan replied 1 year ago.

Drain the hydraulic. The entire tank of oil will spill out if not as the pump is lower than the tank. The transmission Id service after a couple hours of running and then after do a filter change and cut open and inspect for signs of a problem. Monitor it a couple times for confirmation there are no more issues

Customer: replied 1 year ago.
Any way you have a breakdown image of pump our parts guys can't find it hard much appreciated!
Expert:  Dan replied 1 year ago.

The charge pump? What parts are you looking for? Did you get a replacement pump?

Customer: replied 1 year ago.
No sir not yet. And yes the charge pump for the transmission.
Expert:  Dan replied 1 year ago.

I do not have SIS to look up parts diagrams unfortunately. Your Cat Dealer cant find a transmission charge pump?

Customer: replied 1 year ago.
They said it's not called that under their books? Haha
Expert:  Dan replied 1 year ago.

I worked for a Cat dealer years ago and the techs looked up their own parts.... This is part of the reason why... haha

Customer: replied 1 year ago.
sir I understand that! Haha
Expert:  Dan replied 1 year ago.

Try them again and tell them to type in Transmission pump group under your serial number and it will pull up. i promise you. haha

Expert:  Dan replied 1 year ago.

You can buy them aftermarket for a lot less. The link I posted is likely the correct one for your serial number but you would have to confirm that with the seller.

Customer: replied 1 year ago.
Man changed the charge pump and same issue. Are we skipping a step or something? Thanks for the help
Customer: replied 1 year ago.
Absolutely no debris to show internal failure. With pump pressure not building like it should what could cause that?
Customer: replied 1 year ago.
What's causing pressure to bypass or drop when in neutral not moving just idling I don't have any hair left too pull haha
Expert:  Dan replied 1 year ago.

What are all your pressures? If the pump is no picking up the oil, check the suction screen. sometimes a little grease helps but a new pump should be picking up the oil. You have no pressure at all?

Customer: replied 1 year ago.
Same pressure as before 75 psi and no restrictions.. don't know other pressure. Started with pump pressure and was low. So changed pump like you recommended but maybe I skipped a step? Or something
Expert:  Dan replied 1 year ago.

The pump is a fixed displacement so it sounds like you have pressure dumping off either in the converter or in the transmission. This is odd that you only lost 4th gear but have very low pressures. Try testing your pressures in the other gears and let me know the results.... I will have a better idea being able to see the rest of the pressures.

Customer: replied 1 year ago.
I have 4th gear. Just when I go to scoop a load it looses power like torque converter slipping have 75 psi at idle in neutral don't have to shift it to gear for it to drop.
Expert:  Dan replied 1 year ago.

Ahhhh gotchya.... It is common to replace both the pump and converter on a converter failure. Usually the filter and strainer will get stuffed full of aluminum when the converter fails.... But if you are not getting any pressure beyond the converter but the pump suction strainer/tube is not sucking air and it is not restricted, it is a converter problem.... Especially if you are still not getting full pressure to the transmission clutches.... Replace the cooler as well as it could be plugged and will cause an overheating problem

Customer: replied 1 year ago.
Don't think is sacking air but that's the pressure straight out of the pimp on filter housing. Don't know converter pressure
Expert:  Dan replied 1 year ago.

Check at A and B, and C ports at the TC regulator, inlet and outlet pressure. and the others.... sounds like pressure id dumping off somewhere.

(A) Pressure tap for lubrication
(B) Pressure tap for converter outlet
(C) Pressure tap for converter inlet
(D) Pressure tap for speed clutches
(E) Pressure tap for the pump(F) Pressure tap for direction clutches

Customer: replied 1 year ago.
Only have one gauge so can I check them one at a time?
Expert:  Dan replied 1 year ago.

Yes, That is perfectly fine.

Customer: replied 1 year ago.
Converter inlet is only 50 psi at high idle
Customer: replied 1 year ago.
Converter outlet 47 psi
Customer: replied 1 year ago.
How would you check to see if sucking air?
Expert:  Dan replied 1 year ago.

Inspect the suction tube for leaks and the suction screen for restrictions. Make sure the o rings for the hoses are sealing. Inlet should be a lot higher. Either theres a restricted suction line, sucking air, or you have a defective pump out of the box.

Customer: replied 1 year ago.
Checked suction screen again and keep getting Red fuzz from a red rag it looks like. Maybe they left it in there when they rebuilt transmission but can't find it and it's not enough fuzz to stop it up. Checked suction tube and seals and all seem good. Something on inside of transmission on other side of screen that could be wrong?
Expert:  Dan replied 1 year ago.

Maybe the rag is in the suction tube itself....

Expert:  Dan replied 1 year ago.

Check to be sure the tube is totally clear.

Customer: replied 1 year ago.
Tube is clear. The one that bolts to pump itself right?
Expert:  Dan replied 1 year ago.

That is correct. either the Pump is not picking up from a cracked or leaking suction tube, etc. or the pump is defective, or if the line and pump are good assuming the pressure is the same with both pumps you are dumping off pressure after the pump such as in the converter indicating a converter problem. Let me reach out to another expert to see if he has any thoughts as well.

Customer: replied 1 year ago.
Awsome thanks man. About to pull tranny so sooner the better on suggestions. Thanks for all your help!
Expert:  Dan replied 1 year ago.

Pleasure to help. I am right with you on that that the transmission and converter have to come out for rebuild/repair.

Customer: replied 1 year ago.
No cracked pickup or restriction to pump so what's the first thing fluid goes too dick you get another opinion?
Customer: replied 1 year ago.
Did* sorry
Customer: replied 1 year ago.
Don't wanna pull it for no reason because like you said there should be some aluminium in screen or something.
Expert:  Dan replied 1 year ago.

Hi, Yes and we both agree that the red material has to be a red rag that went through the transmission at some point and likely is just shredded into the pieces you are finding. Also, your last step before pulling the transmission is to pull the valve body and disassemble and inspect all the valves and spools, polish with crocus cloth and be sure of free movement in the bores, reseal and reassemble, Recheck pressures and operation.

Customer: replied 1 year ago.
Pull valve body on top of transmission? One with solenoids in it?
Customer: replied 1 year ago.
What is solenoid body and valve body sealed with
Expert:  Dan replied 1 year ago.

Gaskets and o rings. Your cat dealer can print you out a diagram from the parts department

Expert:  Dan replied 1 year ago.

Please take a few moments to rate my service as that is how the experts get credit for their time on the site. Thank you

Customer: replied 1 year ago.
There is no type of gaskets or silicone in between valve body plates but silicone between solenoid body and valve body.
Customer: replied 1 year ago.
Don't see no debris in valve
body though.
Expert:  Dan replied 1 year ago.

It should not be silicone.... O rings seal the solenoids. Obtain a parts breakdown with part numbers from your dealer and go by that. That way there is no room for error. If the valve body checks out then unfortunately you will be removing the transmission for rebuild. Please take the time to rate my service as I have taken the time to help. Its been a pleasure helping.

Customer: replied 1 year ago.
No not on solenoid in between the valve body plates. But I will chwck with them but any way to check anything else to make sure of what's bad because no debris in tranny besides the red fuzz in filter and tranny just rebuild it seems odd but of course I will your getting 5 star haha
Expert:  Dan replied 1 year ago.

Someone used silicone there? I believe there is a gasket that is supposed to be there. If the valve body was installed with only silicone between the valve body and transmission, this is likely a big part if not all of your problem.... Make sure all the o rings are changed as well

Expert:  Dan replied 1 year ago.

silicone wont hold up to the transmission pressures

Expert:  Dan replied 1 year ago.

Use it on the top cover maybe... haha

Expert:  Dan replied 1 year ago.

Also check for straightness with a straight edge and make sure no one used a cookie wheel on the machines surfaces causing them not to mesh and seal

Customer: replied 1 year ago.
Sorry haven't rated yet because knew would need further help. Any removal procedure of torque converter and disassembly of transmission. Have it out and valve body off and where do I look for seals blown in the clutch packs. Can't get cat to send good breakdown.
Expert:  Dan replied 1 year ago.

Hi, Unfortunately Cat breakdowns aren't the greatest with the cut open side views but that unfortunately is how a lot of them are. If you are doing a rebuild on the transmission and converter I would not go in too far without a copy of the shop manual on hand as there are specs and tolerances to follow and one missed step could cost the whole job and a redo. I do not have the complete service book for your serial number for the disassembly and assembly. A lot of times you can fond good used manuals on the web on E bay, etc. I would by all the seals and o rings and at the very least, Re-bearing and reseal everything and inspect the clutches per specs in the manual.

Expert:  Dan replied 1 year ago.

The initial links I posed have the troubleshooting information. Here is some info directly from the links I posted. Let me know the results of these tests. I believe you might be skipping around on the tests and you will never be able to isolate the problem that way and will just get frustrated. I see you opened a new question and are getting the same information we already went over.

Problem: The transmission does not operate in FOURTH SPEED FORWARD position or in FOURTH SPEED REVERSE position.
Probable causes:


  1. Number 3 FOURTH SPEED solenoid valve (2) is inoperative.

  1. There is a problem in the electrical circuit.

  1. The FOURTH SPEED clutch is not engaged or the FOURTH SPEED clutch slips. This may be caused by any of the following conditions:

    1. There is low oil pressure due to leaking piston seals.

    1. The clutch discs and clutch plates have too much wear.

    1. Clutch components are broken.

  1. Selector spool (18) is stuck.
Customer: replied 1 year ago.
Selector spool 18 is located where? All solenoid body and piston seals are good what else could cause it? It don't have power to move any dirt in any gear. Just acts like slipping and have tried everything you recommended with no luck.
Expert:  Dan replied 1 year ago.

Thanks for the update. Its the 2nd and forth selector spool in the control valve. Click on this link for the diagram.

Diagram

Customer: replied 1 year ago.
Took valve body completely apart and had no excessive wear or broke springs. What else do I check for?
Customer: replied 1 year ago.
Could it be the flow control office (10)? Noticed it there
Expert:  Dan replied 1 year ago.

You can check it for a restriction but i do not believe it will cause the problems you are having. I am going to opt out and a fresh set of eyes to come in and help you with this. We have been on this for several months and one question prior to this one. Maybe someone new might have other suggestions.

Customer: replied 1 year ago.
K so how will that work? They'll see what we've already went through and opt in?
Customer: replied 1 year ago.
Where's flow control office located exactly?
Customer: replied 1 year ago.
Transmission neutralizer limit switch location?
Customer: replied 1 year ago.

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