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Ask Glenn Bradley Your Own Question
Glenn Bradley
Glenn Bradley, Technician
Category: Hyundai
Satisfied Customers: 830
Experience:  Ex Transmission Shop owner, Hyundai Powertrain diagnostic specialist
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hyundai Elantra I changed trans fluid and filter on my 1998

Customer Question

I changed trans fluid and filter on my 1998 hyundai elantra and now have no reverse or 2nd and 3rd gear...... Also autozone sold me dex/merc trans fluid and they said thats what their computer said to use but after putting this in is when it started..... I have not had any problems since and the car has 80000 miles on it...... so i drained the trans axle and trans and put the mopar atf 7176 fluid in that chiltons book said to use but still no reverse and it doesnt want to shit out of 1st gear and when it does it slams into second and third is like neutral also reverse is like neutral..... Also when the pan is off and the car not running but the key on when you shift to drive or reverse you can hear the solinoids acuating.......
Submitted: 5 years ago.
Category: Hyundai
Expert:  Mark replied 5 years ago.
If your transmission is failing to engage reverse then it sounds like you have an internal failure of the transmission.

To confirm this, I would suggest you have the vehicle scanned with a fault code reader to get the transmission fault codes that may be stored.

Having said that, the failure to engage reverse is almost always the sign of an internal failure since it does not require any electrical solenoids to make it engage.

I hope this information is helpful and let me know if you need further assistance with this.

Customer: replied 5 years ago.
I had no issues with the transmission at all no hesitation no slippage or anything untill I changed the filter and gasket and replaced what fluid I lost when doing this....... Like i said autozone's computer said to use valvoline max life dex/merc fluid so I did and then took it for a test ride after filling it up and letting run to normal operating temp and checking it again to make sure it is at the level it needed to be at........ Then after driving it for about 15 min it starting not wanting to shift correctly like I said previously not wanting to shift to second gear till very high rpm's then when it shifts to 3rd it acts like it is in neutral like reverse does now also........ Why would I have no issues previously and now I do...... I even rechanged the filter and fluid and put the correct fluid in that Chilton's manual said and still no change
Expert:  Mark replied 5 years ago.
If the only thing that changed from the time the transmission was working fine, until now, was the fluid and filter change then you have to go back in and triple check that the filter is seated properly and not allowing the pump to suck up air instead of fluid.

If you are happy that the filter is installed correctly, then the wrong fluid may have done some damage to the clutch friction materials in the transmission and this would explain why there is no gear engagement or it feels like it is neutral.
Customer: replied 5 years ago.
I've put 2 filters in with the same outcome now there is 4 bolts that hold it in and very little room for it not to seat properly...... Now would this issue cause it to have first gear with no problem and failure on all the rest?
Expert:  Mark replied 5 years ago.
Yes it can because each gear will use a different combination of clutch packs to achieve the desired gear ratio but if there is a common clutch pack that is not used in first, but is used in all others, then that will create your trouble.
Customer: replied 5 years ago.
Now why would the fluid change and filter cause this problem when no other issues have been present or in reality the wrong fluid and the vehicle was ran a very short period of time the car idled for about 30 min total and drove for 10 min and in that amount of time is when it messed up wouldnt it take longer if the fluid was the reason for the problem......
Expert:  Mark replied 5 years ago.
It is important to keep in mind that this whole scenario may just be a coincidence and your transmission could have developed this problem even without you changing the fluid.

Your question revolves around the fact that the fluid change somehow caused the problem, and the possible reasons why it may have caused the trouble, I have given you.

So, what we are left with is a transmission that wont engage reverse, and you are confident that the fluid and filter change are done that eliminates that theory. So that would leave this as being a coincidence..............but it would still mean an internal failure.
Customer: replied 5 years ago.
Now what is it i can change and look into to correct the problem after i scan it and find any trouble codes or what if it doesnt bring any up because the mil is not on at this point....... and what about solinoids and sensors that I can change without getting into a serious trans rebuild job....... when you shift it into reverse or drive or any gear at that I can hear a buzzing sound and in reverse it lasts about 10m seconds or so but when you put it into drive or 2 or 1 it does the same for 10 seconds then comes back on constant and doesnt shut off...... I do not recall hearing these noises before and it does it regardless if the motor is running or not
Expert:  Mark replied 5 years ago.
I'm going to open this question up to the other experts in case I am missing anything..............that way you can get a second opinion.
Customer: replied 5 years ago.
Relist: Other.
Expert not fully certain as to what is going on with my car and unsure as to what the issue could be
Expert:  Glenn Bradley replied 5 years ago.
Hi, it’s Glenn here. I can help you with your question.

I've read the post completely and would like to give you a definite diagnosis.
It's almost impossible to fit the transmission filter incorrectly.
Valvoline Maxlife is ok in this transmission.
Before we get started I just have some questions for you:

1) What was the condition of the original fluid?
Compare it to the scale here:

2) Was the new filter the same shape/size as the original one?
3) When you filled the transmission with fluid each time did you check the level with the engine idling in park or neutral?

Even if I'm offline please post your reply here and I'll respond ASAP. The JustAnswer system will automatically send me an email to let me know of your response.

Cheers Glenn.
Customer: replied 5 years ago.
The fluid was still red not brown or black which would indicate overheating or "burn't" fluid...... It also did not smell burn't like most do...... And the filter was ok no damage twists or anything and like I said I changed the filter twice thinking it was that and not picking up fluid like it should since it took ten min of drive time to mess up.......... Also the engine was running on level ground and idleing in park.......... And if you go off your chart the color of the fluid is right in the middle of the color of new to service due....... It acts as though it is in limp mode and I unhooked the negative battery terminol adn reset the computer to see if that would make any difference and that is when I rechanged the filter and refilled it with the atf 7176 fluid that chiltons says to use...... But still no reverse and I havent driven it again to see about the forward gears but I would asume they are the same....... It just has me completely flustered because like I said there was no issue before and I was just doing normal routine maintenence
Expert:  Glenn Bradley replied 5 years ago.
Ok, thanks for the extra information.

The fluid on this transmission should be checked engine idling in neutral. From memory if it's reading full when in park it may be low when checked in neutral.

Check the fluid level and top it up if required then let me know if it's any different.

Cheers Glenn
Customer: replied 5 years ago.
I checked it both ways and no significant change in level from park to neutral at normal operating temp........ My biggest concern is is it mechanical or electrical..... I talked to a trans shop and he said most likely it is mechanical or I could of pinched a hose or disconnected a wire but there are none anywhere near when changing the filter and putting the pan back on....... And after talking to the hyundai dealership they are leaning more to electrical but without a scanner its hard to tell what it is....... my normal obd2 scanner doesn't bring up trans trouble codes is there a way to check by jumper wire like you can on dodge vehicles to get trouble codes without an expensive scanner....... I just don't want to dump hundreds of dollars on towing to get it scanned and paying to scan and things when I can go and spend a couple hundred on a good used tranny and just be done with it but dont know what to do cause if it is just an input or output sensor of something then I could just change them cheaply and be done...... Idk what to do
Expert:  Glenn Bradley replied 5 years ago.
Ok, I can tell you that you don't have an electronic issue, it has to be mechanical.
If the cable to the transmission was unplugged then the transmission would be in limp mode giving you a good solid engagement into drive (high gear takeoff with no shifts) and a solid reverse.

Your transmission at best has a stuck valve or at worst has a failed low/reverse clutch pack which matches the symptoms exactly.
These transmissions can fail at an early age and I would say that it's nothing to do with the work you have done, more of a coincidence in fact.

A quick pressure test would reveal the problem for sure, if it's a stuck valve then it may be caused by an internal failure which contaminates the valve body, or just simply require a valve body overhaul.
If it's a clutch failure then it will require an overhaul or exchange.

I suggest that you have your local transmission shop look at it for a diagnosis.

Don't forget that if you have any more questions or you are unsure of what I mean in the information provided please ask for more clarification, I'm only too happy to work with you to achieve a good result. Cheers Glenn.
Customer: replied 5 years ago.
Thankyou so much you've given me the best answer so far I appreciate it very much
Expert:  Glenn Bradley replied 5 years ago.
You are most welcome. Thanks for using JustAnswer.

Cheers Glenn
Expert:  Glenn Bradley replied 5 years ago.

If you need any further help with this matter please come back to me via this post and we can continue the current conversation on this question/subject until it times out.

Cheers Glenn.