Engine/Transmission (1998.5 - 2002) Help please!!!

[cmills]

I've got a noise and a thud that comes from the transmission (I think) anytime I am going forward and let off the accelerator and every time I put it in reverse after I have been going forward, it sounds like the input shaft or something is siding forward and backward in the case. It is not a u-joint as they are both new, and the clutch is working fine. Any ideas because I sure don't have any.





thanks,

Cory

 

[blacksheepdiesel]

Engine mount or transmission mount.

Godspeed,
Trent

 

[cmills]

Thanks Trent, but, yeah we thought the same thing but they are fine, Forgot to say that we already checked.

 

[Bessler]

Have you checked the torque on the U-bolts rear axle?

 

[cmills]

Have you checked the torque on the U-bolts rear axle?

We're pretty sure it is coming from transmission by getting under it and listening you can tell that is where the noise is coming from.

 

[JLandry]

We're pretty sure it is coming from transmission by getting under it and listening you can tell that is where the noise is coming from.

Cory,



I had a 1976 IH Scout that did this. Turned out the bolts attaching the transmission bell housing to the engine block weren't torqued to spec. Apparently the bell housing was shifting slightly because of the torque. Tightening up the bolts eliminated the clunk.



Probably not the same problem you have but can't hurt to check.



Good luck,



John L.

 

[Bob4x4]

When you had the driveshaft out did you apply a high pressure grease to the splines of the slip joint ?

 

[Moe]

Is it possible you have chain stretch in the transfer case?

 

[cmills]

we checked most of the bolts that would have any effect and they are tight. Yeah, I did put some grease on splines of the slip yoke and as far as the transfer case I'm sure the noise isn't coming from there, plus it was just rebuilt about 40,000 miles ago so I'm pretty sure its ok.



Thanks for the ideas, keep them coming

 

[Moe]

One more thing. Check to make sure your spare tire is tight. I had a loud thump and it took a while to figure out, but after I cinched my spare, it stopped. Just a thought. Good Luck, Moe

 

[MAllen1]

One more thing to check. Check the driveshaft going to the front axle. The one on mine lost (to this day I can't tell you how) 3 of 4 bolts where it hooks up to the transfer case. Every time I would start off in 1st or reverse quickly it would sling the driveshaft around and hit the transfer case.

 

[cmills]

I know the spare is tight as I just changed the rear axle fluid and I pulled on on it a couple of times, and I checked the front axle and it also is good. I'm almost 100% sure it is in the transmission but I don't know what it would be.

 

[cmills]

I guess we are going to have to pull it out and see if we can see anything that is wrong, let me know if anybody thinks of anything else.



thanks,

Cory

 

[MAngelotti]

I agree with moe, I've had this happen before where previous owner ran case out of fluid and stretched the hell out of the chain. Sounds like any other driveline play but most often only experienced when changing directions.

 

[cmills]

I agree with moe, I've had this happen before where previous owner ran case out of fluid and stretched the hell out of the chain. Sounds like any other driveline play but most often only experienced when changing directions.

You guys might be right, I now think it has something to do with the transfer case, I have noticed that it will never do it in 4-low, only 4-high and 2 wheel drive, but the weird thing is that sometimes after I put it in 4-low and then back in 2 wheel drive it does not do it, which is where I have it right now. I'll see if it does it when I put it in 4-high in the morning because I will probably have to push snow in the morning. Do you still think that this is the problem?



I actually didn't think that when you are in 2 wheel drive that the chain was turning, am I wrong? I thought it just went straight through the transfer case.



If it is the chain how long before I have some major problems, and what is going to happen? I will fix it as soon as possible, just have to have the opportunity. If nothing else happens is the chain the only thing I will have to replace?



thanks,

Cory

 

[Moe]

Its a large chain. I dont think it will stretch to the point of jumping teeth but it might. Make sure it has plenty of fluid in the case. I had another truck that had the stretch for a long time before I had the chain and gears replaced. Keep us informed, MOE

 

[cmills]

Its a large chain. I dont think it will stretch to the point of jumping teeth but it might. Make sure it has plenty of fluid in the case. I had another truck that had the stretch for a long time before I had the chain and gears replaced. Keep us informed, MOE

I just changed the fluid less that 1,000 miles ago so it should be good, so does the chain turn in 2 wheel drive? If so, how could it actually have a load on it if its not turning the front driveshaft?