Whining Transmission

[fzj80kidpen]

I have a 96 that has 156k on her.
When I am accelerating I hear a whining EEE just before the trans shifts to a higher gear. This noise only last a second or two then goes away until I get to the top of another gear range then it comes back and does it again, stops after shifting to a higher gear.
Does not seem to happen in from 1st to 2nd, most noticed prior to shifting to O/D.
The transmission fluid was changed less than 10k miles ago.
I remember a similar thread not long ago but could not find it in the archives.
If I remember correctly someone advised about a vacuum hose being clogged.
I have the FSM but have yet to find and vacuum hoses related to trans.
Any advice will be greatly appreciated.

Bill M
FZJ80Kidpen

 

[Junk]

sounds like more of a whine from the exhaust

search for whine and you'll find it along with posts from folks like cdan

 

[cruiser4life]

I have the exact same scenario going on with my 97 with 150K.

FZJ80Kidpen: You described exactly what's going on in my truck. It started about 6 months ago and happened here or there but not frequently. Now, it's every time I drive around town. I agree that it's not in the low gears. Usually with gentle acceleration (how I normally drive anyway) in the 40-50 mph range. With a healthy push of the gas pedal it quickly goes away until back in that mph range with the rpm's climbing and ready to switch gears.

I've had it to the stealer where I get my trucks maintenanced. After they reportedly couldn't reproduce the sound I'm describing (on 3 or 4 different occasions), I requested a ride along with the mechanic who works on my trucks.

Of course, I produced the sound immediately and continued to do so during a 15 minute ride around town. End result, the mechanic heard the noise and acknowledges the sound, but still hasn't a clue. He feels that it's harmless. If that's the case, I can live with it. Fairly annoying but my main concern is that it's doing damage to the truck the longer it's unidentified and not fixed.

You can almost feel it in the gas pedal and it's right behind the dash around knee level. Right behind the firewall. It's tough to isolate because it won't do it in park or neutral by simply revving the rpm's...

Junk: You mention you think it's the exhaust. That may be the case FZJ80Kidpen but it's definitely not the case in my scenario. I've searched the forum multiple times to see if someone else has a similar problem and this is the closest matching description I've found.

Certainly don't want to highjack the thread, just saying that I have the same issue and would appreciate any insight others may have as well.

Thanks.

 

[fzj80kidpen]

Whining driver

Junk,
You maybe right. My enitre exhaust needs overhauling also but this is from up front. If it is exhaust then it should do it while parked and revd up so I am going to see if I can reproduce this sound while parked.

bill

 

[carolina_cruiser]

Usually with gentle acceleration (how I normally drive anyway) in the 40-50 mph range. With a healthy push of the gas pedal it quickly goes away until back in that mph range with the rpm's climbing and ready to switch gears.

[snip]

You can almost feel it in the gas pedal and it's right behind the dash around knee level. Right behind the firewall. It's tough to isolate because it won't do it in park or neutral by simply revving the rpm's.

I'm interested to find out if you determine if this is the transmission.

I've been trying to figure out what sounds like the same issue. What sounds like gear noise coming from the front of the vehicle picks up at about 40 mph under light acceleration but goes away under heavy acceleration or when off the gas. My suspicion is that it is multiple factors contributing to the noise.

A few suggestions that seemed to decrease the noise for me:
[li]check and thoroughly grease your u-joints - this quieted things down considerably for me
[li]check your front diff - birf soup will make things noisy in the diff
[li]try synthetic in your transfer case - this made things a little quiter for me

 

[cruiser4life]

CC: You're right on target. Other than the synthetic in the transfer case, I just had the things you mention done. U-joints checked and greased, front and rear diffs checked out and lubed, and transfer case checked and lubed.

You're also right that it made a big difference. Certainly not totally gone but much, much better than before the work was done.

My guess is that because these tasks had such a positive impact, it's not solely a tranny issue anyway. My tranny shifts clean and precise and seems OK.

Thanks.

I know you posted it before, but where in the Carolinas are you? I'm in Charlotte.

 

[carolina_cruiser]

As you may have seen in some of my other posts, while I was changing fluids and greasing u-joints my newly replaced axle seals were slowly leaking and re-forming birf soup in the front diff. I'll be very interested to hear what the truck sounds like when I finish re-doing the front axle service.

Another item on my radar is to replace at least one u-joint. When I had the front driveshaft off I noticed one of the u-joints wasn't very smooth - even with fresh grease. I plan to replace (or at least remove, disassemble, clean and re-grease) that u-joint and check the ones on the rear if the noise persists.

I also plan to have an alignment done. The local shop told me I'd have to take it to the dealer and I haven't gotten around to it yet. It's not badly out of spec but with a subtle problem like this I think it's better to cover all the bases.

If I get all of the maintenance done and am satisfied that no damage is being done I'll simply turn up the radio and live with the noise.

Answering your other question, I'm in Durham.

 

[fzj80kidpen]

Cruiser4life,
Your sounds seem to matchup with what I am hearing. From the knees is the location. I have not had a chance to test the exhaust theory yet but will probably do so tonight. I will let you all know what I find.
carolina_cruiser,
I have not greased the u-joints,etc so this will be second on my list.
I will then let you all know what changes.
As to location, I'm in Winston-Salem.
Looks like we have the piedmont covered.

 

[concretejungle]

Cruiser4life,
Your sounds seem to matchup with what I am hearing. From the knees is the location. I have not had a chance to test the exhaust theory yet but will probably do so tonight. I will let you all know what I find.
carolina_cruiser,
I have not greased the u-joints,etc so this will be second on my list.
I will then let you all know what changes.
As to location, I'm in Winston-Salem.
Looks like we have the piedmont covered.

I think that you guys are feeling the u-joints. I have the same issue from time to time. Not really a winning, but more of a vibration. I'll grease the joints and it's gone for a while.

I'm in High Point/Greensboro.

 

[fzj80kidpen]

Last night I tested out the exhaust theory.
Parked put it in Neutral and revd up slowly to 3500 rpm.
Stopped around 2000, 2500, 3000, 3500rpm
No noise.
I think this blows the exhaust theory.
This sound is more of a clutch sliipping sound.

FZJ80Kidpen

 

[carolina_cruiser]

Tossing out another theory, I looked at the splines on the inner axle where they enter the front diff and the "plateau" at the top of the splines was about 1/2 worn away. I wonder if this wear could be the source of the whining noise?

fzj80kidpen or cruiser4life - have you had occasion to look at your inner axle splines recently? If so, what was the condition?

 

[fzj80kidpen]

Repacked front axle last spring
Everything looked great
I would think that would produce a constant sound that would increase with intensity with increasing speed.
I really think this sound is related to the transmission due to how it is related to the shift points. I am going to carefully check the trans fluid while hot this weekend.

 

[cruiser4life]

Wt

My splines look OK. Really don't know.

For now, I am going to live with it and if it gets worse or easier to isolate, dig in some more.

I guess like Carolina_Cruiser said, just turn up the radio!

Carolina_Cruiser - I just PM'd you on another topic.

 

[robbie]

One place to look expecially if you have recently changed the t-case fluid(and sound dimished) is the output for the t-case. If you have any seal leakage or movement (up down, lateral) of the flange, it might be time to replace the sealed bearing. I have done this on a couple of truck with similar sound you guys describe, and it has been successful. Just a thought for you. (other info in a post on t-cases going on) later robbie

 

[cruiser4life]

Thanks Robbie. I will check that out pronto!

 

[concretejungle]

I swear, with the expertiese (sp?) on this board, it's like having your own personal mechanics 24-7 to help diagnose and fix your trucks. Truely awesome.

 

[cruiser4life]

It's truly invaluable in my opinion.

 

[fzj80kidpen]

Truely appreciate all the advice.

 

[carolina_cruiser]

FWIW, I got my front axle back together over the weekend - complete with new grease and gear oil. The whining is markedly quieter now. This may not be your specific issue, but fresh clean lube in the front diff made a huge difference for me.

 

[robbie]

A dignostic trick to find problems is to install heaver gear lube into certain areas, the front diff, t-case, or rear diff to see if the sound gets less, if so then you may have found the isssue in the componet. I have used 90-140 at times to find problems then change back to stock lube, unless I do not have the time to work on my truck at the time.
Noise travels at times and can be hard to pinpoint down, It some times takes great effort to find the problem. later robbie