Clutch noise

[miller]

I bought a tranny and tcase that I am going to start rebuilding in a month or so. My problem is intermittent. I drove it for a month and a half without any issues, but drives were short. I just took a longer drive and the issue came back. So when the tranny or transfer case are heat soaked the issues comes back. I do not think its the clutch. It sounds to be in the tranny, but I guess could be in the tcase as well. Keep me updated.

 

[miller]

I rebuilt a tranny and transfer case that is ready to go in. I removed the tranny and transfer case today. I pulled covers and inspected both, but no smoking gun. I removed the clutch and verified it was installed correctly. I inspected the pilot bushing. It has about 1/32" wear on the I.D. It does not appear that is was spinning inside the housing. I did not lube the pilot bushing, did some research and said not to self lubricated oil lite. All the clutch plate springs seem tight. Throw out bearing nice and smooth, KOYO brand. I went back and watched the video. I think it is most likely the squirrel cage bearings on the output shaft of the tranny. The noise changes when shifting from 1st to 2nd and that is right where the bearings are. At least I hope so!

 

[miller]

Here are some pictures of the clutch I removed. Everything looks fine.

 

[honk]

Are those flywheel bolts fully torqued to spec?

Are they the factory flywheel bolts?

It's hard to say looking at your photo but I don't like the look of those bolt heads. They look like they might have been rubbing or something.

A loose or cocked flywheel would make some hellacious and odd noises.

 

[miller]

The PO installed the clutch plate backwards and the springs were hitting the flywheel bolts. When I bought the truck the clutch was slipping and that was why. Thanks.

 

[miller]

I have installed the rebuilt tranny and tcase. I have a lot of short trips around town and a one hour trip. The noise has not returned. I do have the old units, but not in a rush to tear anything apart.

 

[miller]

Noise came back today down shifting into 2nd gear at the end of a 70 mile trip. Then once I got in the truck to leave and shifted into reverse it came back. No issues on the ride home. Same noise with different tranny and tcase .The only thing from the old tranny is the top shift plate was used on the rebuilt tranny. I am starting to think oil. I am using an autozone 80w90. What are others using? Thinking of going to the redline met-90 or mobile 1 75w90 to see if that makes a difference.

 

[miller]

Replaced autozone 80w90 hypoid gear oil with redline mt 75w90 in both tranny and transfer case. Just drove a 300 mile trip with no noise. I think it was the autozone oil!

 

[cult45]

Wow, what a way to find out!

 

[miller]

Yeah it would have been nice to to have tried a different oil first! Hopefully this thread will save somebody some time and money!

 

[RWBeringer4x4]

Hey Miller - just curious, did the noise stay gone after you replaced the oil? I only ask because I’m not having a weird grinding noise coming from my transmission - primarily when coasting with the clutch in, and the transmission engaged in 3rd or 4th gear. (ie: either a short coast or downshifting).

I’m fairly sure there’s 80W-90 Valvoline in there. Haven’t checked fluid levels just yet.

I’m leery of the usual culprit (throw out bearing) for clutch-depressed noises - because it only happens when the truck is moving and the transmission is in a gear. (So in gear, but unloaded) Otherwise there’s no noise.

Did confirm it’s not making contact with the pressure plate when it shouldn’t be - clearances seem ok from that I can see.

 

[miller]

Never came back. I run the redline MT90.

 

[RWBeringer4x4]

Never came back. I run the redline MT90.

Did you ever figure out where the grinding was coming from? Just curious how oil could change the situation… the only thing I can think of is if the synchros need a specific type of oil or something.

 

[miller]

No being it never came back wasn't worried about it.

 

[MDH33]

Good timing on an old thread. My '69 is making the same noise. I was sure it's the throw out bearing and was about to order a clutch kit, but now not so sure. Mine started off with just the noise but now it's difficult to get into gear while running.

 

[bikersmurf]

Good timing on an old thread. My '69 is making the same noise. I was sure it's the throw out bearing and was about to order a clutch kit, but now not so sure. Mine started off with just the noise but now it's difficult to get into gear while running.

Difficulty getting it into gear while running points to a clutch that isn't disengaging. Number one suspect would be a failing clutch slave or clutch master cylinder.

Does it work if you pump the clutch? Has it lost fluid in the clutch master? At the slave? They usually last about 8-10 years, but results will vary.