Engine/Transmission (1994 - 1998) Need help with backlash

[HCanales]

I'm having trouble with my drivetrain, I should have put the thread in this section but I thought... well I wasn't thinking, the only thing I was thinking

was $$$. Anyhow, I put a thread on 911 forum, its about my drivetrain backlashing and clanking loud. I think its in the trans. because when I park the truck in first gear or any gear and rock it back and fourth it makes a skipping sound in the transmission. As long I don't release the throttle too fast or get on it too fast it won't clank. Is it possible that it could be the trans or

do they just wipe out. I don't think the transfercase is bad, because the noise is comming from the transmission. It started as a faint clank in fith gear in the morning and by the afternoon it ended clanking in all gears, "loudly!".

please help thanks

HCanales

 

[B.G. Smith]

If you have a place where you can run on a dirt road, try running in low range and see if it still makes the noise, since it is doing it in all gears, I would guess it's in the transfer case. Like maybe the shifter sleeve to the planetary gear. I am not experienced with this transfer case, just looking at a picture in manual. bg

 

[HCanales]

If you have a place where you can run on a dirt road, try running in low range and see if it still makes the noise, since it is doing it in all gears, I would guess it's in the transfer case. Like maybe the shifter sleeve to the planetary gear. I am not experienced with this transfer case, just looking at a picture in manual. bg

I did try the 4WD,it still does it in all gears, U joints looked good also . It stinks because this is my only vehicle now :{ !

Thanks Smith

HCanales

 

[Jschafer]

TDR issue47 has a tranfercase noise fix on page156 I don't know if this could be your problem.

 

[HCanales]

Hello TDR members,

Today I drove my truck and figured out how to make it clunk or clank on demand.

Here is how I do this, in sequence:

1. While in 2nd, 3rd, 4th, or 5th decelerate using the engine.

2. Push the clutch without putting a positive load(accelerating) on the drivetrain, the clutch must be pushed in a decelerating state.

3. Come to a complete stop in neutral.

4. Put in gear and let out the clutch and there will be a clunk a very noticeable one at that.

5. Hopefully that will paint a better picture to whats going on.



This noise has got me stumped. Maybe its not the transmission, I really don't know,

but I need help guys. The reason I thought is was the transmission, because the noise seemed to come from there when I rocked back and forth with the engine turned off in gear. Now my assessment has changed because I think it would have broke by now. How can I distinguish it from the transmission, transfercase, or the diff? Any help would greatly be appreciated, thanks.

HCanales

 

[bmoeller]

How much backlash in the diffs?

 

[Tardog]

Just a thought. Try shifting without the clutch and see what happens? I'm thinking that maybe the center is going out on the clutch? Although this would not explain why you don't get it in 1st. ?

 

[HCanales]

The diffs seem to be fine, I have not really pulled the cover off, but I checked it turned off in gear with someone rocking the truck. All my noise

was coming from the trans in the bottom by the pto covers. The noise resembled an auto trans selector shifting rod/linkage(clank clank), the noise sounded just like that. It reminded me there was a problem when I accelerated kinda hard to merge into traffic, it felt like it momentary disengaged and jolted hard when it engaged. It hasn't done this anymore because I've been babying it and I learned how to drive it accordingly, "like walking on egg shells!". Maybe these details will help you make a better assessment.



As for the clutch I've thought of that too, but I've always thought they're either good or bad. The center of clutches can go out? It kinda makes sense though, because it does it in 2nd on up throu 5th and barely in 2nd. How can I check this?



Thanks guys for your inputs it helps tremendously, I'm in a desperate need of

help so again thanks.

sincerely HCanales

 

[Tardog]

I'm not a clutch guru by no means, but I have had a clutch loose a spring that would catch the flywheel mounting bolts and produce a nock when I used the clutch. It finally gave up when sitting at a stop light things got bound up and truck learched into traffic. What about the T case drive chain having a split link or? Keep us posted as you diagnose, Cheers

 

[HCanales]

I'm not a clutch guru by no means, but I have had a clutch loose a spring that would catch the flywheel mounting bolts and produce a nock when I used the clutch. It finally gave up when sitting at a stop light things got bound up and truck learched into traffic. What about the T case drive chain having a split link or? Keep us posted as you diagnose, Cheers

Did this happen to your 97 with the clutch? If so how long did it last before

it gave out on you? As for the T case I'm not sure about the chain having a

split link. I know I have a busted t case that came with a pto plate and mine

doesn't have the pto plate, perhaps the internal parts interchange, if even

the t case is the problem. Thanks a million!

sincerely

HCanales

 

[HCanales]

I know one sure way to confirm my problem !

HCanales

 

[Tardog]

Sorry, shoudn't have got you worried. No it wasn't my 97, it was an 83 GMC with the diesel (was actually a pretty good truck).

 

[Tardog]

You can always remove the rear drive shaft (put a baggie and duck tape over the tail of the T case to prevent fluid lose) then drive in 4x4, this will tell you if it is a back lash/dif problem or not. Just a way to isolate things?



Edit: I just noticed you are a quad cab, so no baggie required

 

[HCanales]

Sorry, shoudn't have got you worried. No it wasn't my 97, it was an 83 GMC with the diesel (was actually a pretty good truck).

Tardog,

After trying several different things I'm beginning to belive its the clutch like

you mentioned. I was talking to a friend in Arizona and he seems to agree also. Reason being is because during deceleration I'm applying back pressure

on the drivetrain and the clank/clunk is present with forward pressure there after.



So here was the next thing I tried:

First, I set the parking brake and I put the trans in reverse. Then, I lugged the engine a little in reverse to apply back pressure. Finally, I applied forward pressure in a foward gear... NO CLANK!



Why no clank/clunk?

Reason, the clutch is turning the same direction, doesn't matter what gear your on. The only way I can manipulate the clutch is by decelerating or pushing and pulling the truck while the engine is off, this will move the input shaft inside the clutch.

Anyone else agree?

HCanales

 

[B.G. Smith]

Makes sense, the cushion springs in the center must be gone. bg

 

[HCanales]

Need a opinion... If it were you, would you replace the pressure plate and

throw bearing or just the clutch? The clutch system only has 40k and never

sliped once. The Centerforce pressure plates seem to be impeccable and

I hate wasting things, "its a shame". On the same note, I'd hate to have to

change the system out again. Perhaps, the other parts still have plenty of

life left and will get me thousands of more miles.

I guess what I'm trying to ask is what is feasible in this situation. Thanks

your perspective is greatly respected and appreciated.

HCanales



note: bearings are inexpensive I may just replace them

 

[B.G. Smith]

I would replace the pilot bearing and the throw out bearing. If the pressure plate shows no damage, I,d put it back in. bg

 

[Tardog]

Ditto, Are you doing the repairs yourself?

 

[HCanales]

Ditto, Are you doing the repairs yourself?

Yes, I'm doing it myself, but I have access to all the required equipment

for $2. 00 an hr. at the base I'm stationed at.

 

[HCanales]

Does anyone know if I can use a different brand of clutch disc other than Centerforce with a Centerforce pressure plate?

Thanks

HCanales