Hello and welcome to JustAnswer!
Can you explain a little more about what happens?
Does it slip when it's under a load?
Does it slip only at a shift point?
Does it sort of feel like it's shifiting back and forth a couple times at a shift point?
Does it do it more or less depending on the temperature?
Does the check engine light come on?
Does the fluid have a burnt smell at all?
Is it second and third gear that both slip, or it's either one or the other but you're unsure which?
First of all, thanks for the quick response.
1. It slips when shifting to 2nd or 3rd (I am not sure which gear).
2. It does only slip at a shift point.
3. It does feel like its shifting back and forth a couple of times.
4. It does it after it gets on temperature.
5. There are no lights coming on.
6. There is no burnt smell.
7. Only one gear slips, I am not sure which one, but it is more likely the third gear.
A mechanic did attach a computer to trouble shoot, but he says that it appears that the transmissions of the Dodge diesel trucks are not electronic. He checked the rest and the computer did not give any sign of problems with the truck.
When the transmission slips, I have to draw back a little bit on the gas and than it will shift.
Hope you can help me with my problem. I went to the dealer and they charge me about $1,600.00 only to lower the transmission to see what is wrong.
Awaiting your prompt reply, I remain.
There are a few possibilities.
First, there was a service bulletin for shift issues on these at the 1-2 shift. They will shift hunt on light acceleration, feeling like it's going back and forth between first and second gear quickly a couple times before it stays in second. The TSB involved relacing the governor pressure solenoid in the trans. This is mounted to the right side of the valve body.
If it's happening going into second it could also be the kickdown band slipping. This is the front band and it's only used for second gear. It could be slipping from lack of adjustment (should be done every 30,000 miles), or it could be slipping because the servo that applies it is leaking. I've seen this issue caused by a deformed O ring on the servo piston that applies the band. This allows fluid pressure to bypass the piston and the band slips. This wouldn't require trans removal either.
Another possibility whether it's slipping into either second or third would be a slipping rear clutch. If the clutch is worn or leaking when the band comes on for second gear it will overpower the rear clutch and allow it to slip.
I've also seen some front clutch failures in these. This would give you slippage going into third gear. The 48RE's have held up very well, but if I had to pick something as the most common internal issue, a failed front clutch would be it.
I would rule things out systematically. If it's slipping going into second, start with adjusting the kickdown band. If that doesn't help and it's second gear, then I would drop the pan and replace the governor pressure solenoid and/or have a look at the kickdown band servo piston. (This would require valve body removal)
If these things didn't help, or the problem is happening going into third gear, then it would be time for disassembly to inspect the front and rear clutches.
Thanks very much sprinkles.
By the way you explained it to me, I can see that you really know what you're talking about. Indeed a mechanic explained to me that the 2nd gear is a band and that the band might be slipping and that it has to be adjusted, but that you will need a special tool to do the adjusting.
Again, thanks a million. I will follow your advice and try them out. I will let you know how it turned out.
The only thing special to adjust the band would be an in lb torque wrench. The aduster lock nut is backed off and the adjuster itself is torqued down to 72 in lbs. It's then backed off a certain amount of turns, 1 3/4 turns in your case, and then the lock nut is tightened back down while holding the adjuster from moving. It's not hard or time consuming really, and isn't a bad place to start.
I'd love to hear an update when you do get it fixed. You can come back and reply here at any time. Thank you for the accept and the generous bonus!
My pleasure, I will let you know as soon as I get the trans fixed.
Have a great night!