Trasnfer case chain slipping? Clunk/Clack Noise from TC

[Josh1254]

I picked up a 91 325ix Auto recently and didnt realize the front driveshaft was completely missing. The splines on the transfer case were good, and I drove the car home over an hour on the highway. From what I read, that means the VC is working just fine. The only thing I noticed was a vibration in the drivetrain, which I noticed the transmission/transfer case mount is pretty worn out.

I installed a front driveshaft this week and there is a loud clunk/clack sound under acceleration. Its pretty bad. AWD does work and I put a jack under the rear end and the car did move slightly forward with a bit of throttle.

Considering I am able to drive the car without the front driveshaft in place I have ruled out the VC. I read about the possibility of the chain/gears in the TC being worn and slipping. I have not checked the fluid level but I suspect it could be low.

Am I on the right track? Any other ideas?

[audiquattrot]

are you 100% sure that front driveshaft you put in has good splines? The symptoms do sound like something is stripped, whether it is the input/output splines.

[Josh1254]

I got the driveshaft from another R3V member who was parting his out. The splines looked great. On the TC side there was some light dirt I cleaned out but it also looked and felt great. No signs of wear at all. I used the proper grease and everything fit very tight.

I can get the car off the ground sometime this week and look closer, but I really don't think that's an issue.

[nando]

if there's no driveshaft the chain isn't going to slip. the only thing that the chain drives is the front wheels, so with nothing connected there's no load on the chain.

[Josh1254]

if there's no driveshaft the chain isn't going to slip. the only thing that the chain drives is the front wheels, so with nothing connected there's no load on the chain.

Correct. Thats why I was able to drive it home on the highway without any real issue.

Once I installed the front driveshaft is when the problem started.

[TehRaydarlover]

Maybe something to do with the front diff or axles? They wouldn't be under load when you were driving without the front driveshaft.

[nando]

if the splines on the TC are good I'd put money on the front diff being shot.

I'd be surprised if the VC worked but the chain was so bad that it skipped - that would normally imply the thing was run bone dry for an extended period, and a car that poorly taken care of would usually have a bad VC too.

does it only do it under load or is it constant?

[Josh1254]

The front diff was full of fluid that didnt look too bad

It does it under load, I went up my long driveway and I could hear it pretty bad, while going down the driveway it was not happening nearly as bad, if at all.

The previous owner wasnt an enthusiast, and the car was only locally driven for the last several years. Basically it was a second car. It has 138k with a working odometer.

[nando]

well, it could be the chain. either way, I think the reason the front DS was removed is because of the noise, and because it drives fine without it (except for being RWD).

The real bummer is the chain is essentially NLA - you can buy a new one but it's something ridiculous like $900.

[z122643]

Could he be missing a tooth on the front output shaft in the xcase?

[z122643]

also what ratio differentials do you have? If the shaft was missing this might be an unfinished or botched project?

[nando]

Could he be missing a tooth on the front output shaft in the xcase?

no.. either it's stripped, or it's good. there's not much in between. 1 tooth missing out of ~43 isn't going to do anything. :p

[audiquattrot]

i had a driveshaft that appeared to have good splines....but was slightly worn....it was enough for it to slip and not have another material to grab. Its crazy how fine they made these splines from the factory. Not sure why they didn't use a coarser spline.

[Bmjpv]

bad chain

Sound like it could be a bad chain. Because it is and auto trans the transfer case seal gets hard and leaks all of its fluid into the auto trans. Low/lack of atf in transfer case causes the chain to get hot/wear and stretch . Just my vote on what you will find . Good luck

[flyboyx]

i agree with audiquattrot. i have had a few ix's in my day making noises like that. for me it was always the connection between the front ds and tc.

do your tires match? were they all bought at the same time with the same tread wear?