Transmission Problem? (PLEASE HELP!)

[quote:fa2828596f="Jeepster01"]I have a 2001 Jeep Grand Cherokee and when it goes into 4th gear, over 80 km/hr, it will do the following:

If the car is reving at 2500 RPMS before shifting to 4th gear it will jump up to 2600-2700 RPMS then down to 2300-2400 RPMS then back up to 2500 RPMS.

So in other words when it shifts into 4th gear it jumps up in RPMS, then down and back and then back up to its current RPM.

(THIS IS ONLY DONE IN 4th GEAR ALL THE REST ARE PERFECTLY FINE!)

I have brought it to have a diagnostic done and there was no problems with the transmission. The transmission place told me that it could be a wiring problem but not sure if this would be the cause of it doing it to only one gear.

I was thinking it could be a temperature sensor but not too sure.

If anyone has any answers or suggestions please post them.

Thanks![/quote:fa2828596f]

Hey Jeepster
When you had the diagnostic done, were there any codes pulled? Does it feel like the trans is slipping or just having an issue with it trying to "find" the right gear? Let us know!

Chris

There were no codes and I had the TPS checked and it is within range.

I had one of the Transmission shops take a "Movie" of the car shifting and he said that everything seems to be normal.

To answer your question it seem to have a difficult time finding 4th gear. It could also be considered asslipping but the thing is it is on 4th gear every other gear is perfectly fine a smooth going in.

Thanks for your response and I hope you can help.

Hey
After re-reading your description, it is possible the solenoid that controls fluid for the 4th gear shift is clogged w/ debris or may be failing. Another possibility is that the fluid may need to be flushed, did the tech make any recommendations to that respect ie:fluid old, worn or burnt smelling? Allot of these types of shifting problems can be solved with a fluid flush (not just a drain and fill)

Chris

No the tech only came up with the solution that it may be a wiring problem and that was all.

How would I be able to tell if it the solenoid or if has something to do with the fuel?

How would I go about troubleshooting this to find out if it is the problem?


Thanks for your help and please post any suggestions.

[quote:4d20c6df67="Jeepster01"]No the tech only came up with the solution that it may be a wiring problem and that was all.

How would I be able to tell if it the solenoid or if has something to do with the fuel?

How would I go about troubleshooting this to find out if it is the problem?


Thanks for your help and please post any suggestions.[/quote:4d20c6df67]

Hey,
Testing would require a mutimeter and a wiring diagram or a scantool that can view transmission data

Chris

p.s. You mentioned fuel???? Is there something going on w/ the engine also?

I did a scan on the transmission and came up with nothing. Everything is within range and this is why the Transmission shop I went to had mentioned it being a wiring problem.

I mean to say fluid not fuel, sorry.

So what would you recommend I do first, a full flush of the transmission and all lines and see if that solves it, if not then would you recommend changing the solenoid?

Can a test be done on the solenoid to verify if that is the problem and if so how do you test for that?

Thanks again!

[quote:dd0e52f404="Jeepster01"]I did a scan on the transmission and came up with nothing. Everything is within range and this is why the Transmission shop I went to had mentioned it being a wiring problem.

I mean to say fluid not fuel, sorry.

So what would you recommend I do first, a full flush of the transmission and all lines and see if that solves it, if not then would you recommend changing the solenoid?

Can a test be done on the solenoid to verify if that is the problem and if so how do you test for that?

Thanks again![/quote:dd0e52f404]

Hey,
Certainly the flush would be the quick and easy and if its never been done then I would recommend it. A good number of times the electrical part of the solenoid valve is fine yet the mechanical part of it is either "stuck" or very "sticky". Having said that, I would say that if the fluid flush gets you no results then a replacement of the solenoid assy would be recommended.

Chris

That soumds perfect, thanks.

Would there or could there be any other reason other than the solenoid that is giving me this problem. I dont want to have to go and change the solenoid to find out that the problem is something else.

Thanks again Chris!

[quote:23515f8646="Jeepster01"]That soumds perfect, thanks.

Would there or could there be any other reason other than the solenoid that is giving me this problem. I dont want to have to go and change the solenoid to find out that the problem is something else.

Thanks again Chris![/quote:23515f8646]

Sure there could be other reasons! (sometimes I really with I could "plug in" to everyones vehicle that I try to help here and give them an accurate, take it to the bank, diagnosis! Seriously!) If your going to do the work then a careful inspection of the connectors and harness inside the tranny is a gimme! If you need component locations, diagrams or procedures let me know and I'll post them here or zip 'em up in an email to ya! Let me know!

Chris

I appreciate your help Chris.

If you dont mind e-mailing that to me at the following address that would be great.

kingsi01@hotmail.com

Thanks again Chris!

Will gather up the goodies and send it to ya by the morning!

Chris

[quote:9cacfd4a99="carundell"]Will gather up the goodies and send it to ya by the morning!

Chris[/quote:9cacfd4a99]

Chris,

I am having what sounds to be the same problem. Could you please send me the same information?

Jeepster01,

Also, I would be very interested in seeing what you have done since and if anything has worked to solve the problem?

Here is a description of my problem (if it's applicable):
I've got a 2001 Jeep Cherokee 4x4 Sport with and Auto Trans. It's just when over 70K miles. I've just recently noticed that when driving at 50 or better it seems to jump between gears. When going 50mph it will jump from about 1500rpm to about 2100rpm. There is no change in modulation to the gas pedal and this is done on a flat road so there is no change in hill accent/decent. I first noticed the problem when the car was going between 60-70mph. The RPM's will jump up for a little bit then jump back down. It will continue to do this for a while. I'm not sure how long this would go on as my typical drives are not great in distance. It has been getting significantly colder and I am wondering if that could be part of the problem, but I fear that this isn't it. My inclination is that it might be: a sensor, something with the transmission, or throttle body (just putting it out there). Has anyone had a similar problem or knowledge of potential solutions to this problem?

Thank you for your time,
Sixstar08

Hey six,
By chance have you had the vehicle scanned? What is the condition of your trans fluid? Smell burnt? Or discolored? (should be bright red) Let me know!

Chris

[quote:6cc53e4aed="carundell"]Hey six,
By chance have you had the vehicle scanned? What is the condition of your trans fluid? Smell burnt? Or discolored? (should be bright red) Let me know!

Chris[/quote:6cc53e4aed]

I do not know the current condition of my trans fluid and I have not had the vehicle scanned. I am bringing it in very soon for routine maintenance. Are there any things in particular I should have them look for?

Also, I had sent my problem to another mechanic i know for and this was there response.

All - an extreme likelyhood it NOT internal to the trans (we simply don't have problems with AW-4s). Your description is consistant with:

1)A misadjusted Throttle valve cable.
2) a "noisy" (varying voltage with no position change) from the TPS (throttle positon sensor). Unless the condition is real bad, it won't set a fault or turn on you MIL light.

Transmission throttle valve cable adjustment is extremely important to proper operation. This adjustment positions the throttle valve, which controls shift speed, quality, and part-throttle downshift sensitivity.

If cable setting is too loose, early shifts and slippage between shifts may occur. If the setting is too tight, shifts may be delayed and part throttle downshifts may be very sensitive.

Hey Sixstar08

Did you by chance get your vehicle scanned and Iron out what the problems may be with your transmission?

Please let me know!

From Jeepster01
Hey Sixstar08
Did you by chance get your vehicle scanned and Iron out what the problems may be with your transmission?
Please let me know!

From Sixstar08
checked tansmision fluid color. still the red pink color it's suppose to be not burning smell. took it to the shop to get scanned. today. so far they're still not done, but they've had the car for going on 8 hrs. so that's not sounding too good. said they checked the tps and it was fine. they said something about it bogging and then having problems starting. possibly miss firing, but that's something that i had not experienced with it doing. funny it worked just fine when i brought it there this morning. anyways still waiting to hear back from them on the news. i'll give them a call back in a bit.

From Jeepster01
Can you please keep me posted as to what they find if anything. You have the same problems as I do and I cant seem to find out what it is no matter where I bring it.
I have brought it to 3 different shops, one had it for 2 days, one for the whole day and same with the third.

From Sixstar08
they said it was that they need to rotate the valve springs because the engine was miss firing. it's funny i brought it in this morning, they took 2 test drives and found nothing. they turned off the car were going to say nothing wrong with it, tried starting it up and it was bogging. they said it was miss firing and now to rotate the valve springs it's gonna cost $650 and that's not including the $70 scan. I'm supper pissed at the moment because it took them 9 hrs to figure it out and now i have scramble to get a ride to work tomorrow so i don't miss another day of work, but i hope this helps you with the problem.
ps sorry for the spelling mistakes

From Jeepster01
So there is nothing wrong with the Transmission?
You said you have a problem with it having a hard time getting into 4th gear. What outcome did you get from that?

From Sixstar08
From what they told me there was noting worng with the transmission. I know, i'm confused too, which leads me to believe that either they are fixing it because they "think" it needs to be done or because they did something to it while in there possesion. If it fixes the problem with the "slipping" feeling i'll let you know but i will not get the car back until tonight at the earliest.
I was talking a another friend of mine, on a side conversation and he said maybe the torque converter.
But like i said i'll let you know more when/if i pick it up tonight.

From Sixstar08
they said it was that they need to rotate the valve springs because the engine was miss firing. it's funny i brought it in this morning, they took 2 test drives and found nothing. they turned off the car were going to say nothing wrong with it, tried starting it up and it was bogging. they said it was miss firing and now to rotate the valve springs it's gonna cost $650 and that's not including the $70 scan. I'm supper pissed at the moment because it took them 9 hrs to figure it out and now i have scramble to get a ride to work tomorrow so i don't miss another day of work, but i hope this helps you with the problem.
ps sorry for the spelling mistakes

Six....... Rotate valve springs??????? the only thing you rotate is tires!!!!!!! Email me a copy of the bill ya got and lets get this on the straight and narrow ..... sorry for my frankness ....but ...... something sounds fishey as HE**!!! ....... you may be a victim!

Chris

My 2 cents. I agree with Chris on the filter and fluid change using the right fluid. This may or may not resolve the issue. Wouldn't surprize me if there was a sticking valve. ***What in the world is with rotating valve springs????

*never heard of it*-not that I have heard of everything. I will add that I have seen fuel injector and intake valve problems on the 4.0 motor that can be cleared up sometimes with cleaning procedures.

i agree with chris too on the fluid change, but rotating valve springs?! i guess they need to replace the muffler bearing too!!! sounds to me like a crooked shop.


shane

I have a 98 Jeep Cherokee XJ, 4x4, 4.0L, with 168,000 miles on it. This is the first time anything has ever gone wrong with it except for routine maintanence. Could you e-mail me the same info. please? jeeplover81@hotmail.com Thanks so much

I have a 2003 Jeep Liberty, it does the same thing. chrysler/jeep actually wrote this into the owners manual as normal operation, I think they couldn,t fix it so they put it in the manual. It's not downshifting like it seems, because when mine does it , I'll turn off overdrive then it downshifts to third gear. I've learned to live with it, but that sucks.