Hideous noise, I think transfer case

I need help identifying a hideous growling noise that I believe is the transfer case but I would like some second opinions. I'll do my best to describe what's happening.

If I sit stopped with the clutch depressed and in gear and rev up the engine, I hear (and feel) a nasty growling coming from underneath. Rev it up with the clutch depressed and the transmission in neutral, no growl. If I put the transfer case in neutral it doesn't make the noise regardless if whether the clutch is in or not. This is why I think it is the transfer case.

One other note, when it is making the noise, the car wants to move. For instance, if I have it in reverse with the clutch depressed and rev it up, the noise will start and the car will start creeping backward -- barely noticeable.

Any help would be very much appreciated.

 

Your clutch disk may be in backward.

Your bell housing bolts could be loose.

Your trans to bellhousing bolts may be loose.

Your throw out bearing may be bad.

If, as you state above, this happens stopped, but in gear, the noise is not tranny or transfer case related.

 

I remember being very careful about which direction the clutch went in -- not saying I still didn't mess up but...

I will check the bolts you mentioned to make sure they are tight. My first thought was throw out bearing but I ruled it out because it only happens while in gear and not neutral with the clutch depressed. In fact, I can have the clutch depressed, rev it up to make the noise and then knock it out of gear with the clutch still depressed and the noise subsides. Would a bad throw out bearing still act up regardless of whether in gear or not?

 

Yes.

My first thought was a bad throw out bearing...

As a side note - Stout - I've been reading your trials and tribulations of getting this Jeep back on the road and I wanted to tell you that I hope you're not getting discouraged. I remember the first time I finished a rebuild and thought I was ready to enjoy endless evenings of cruising to the ice cream shop, only to discover that I had "6 more weeks of bad wrenching"... Leaking brake lines, greasy U-joints, strange sounds, electrical gremlins... It happens to the best of us. But luckily, you're getting it worked out and once you do a few things twice, you won't have to mess with them again.

Keep posting the progress - we're all living vicariously through you and I, for one, really enjoy it!

(JEEP wave)

 

Thanks. No, I expected to have bugs to work out and I'm not getting discouraged. I'm regretting pulling the transmission back out but other than that, the bugs have been expected -- a few leaks and noises here and there.

So if the throw out bearing would act up regardless of whether the transmission is in gear or not, then that rules that out. What would cause the vibration and growl with the clutch disengaged in gear but not while in neutral? Even with the transmission in gear but the transfer case in neutral, the sound goes away. Only with both in gear but the clutch pedal pushed in does it make the nose and vibration.

Aside from the things that Mike suggested, which I will check, what else could it be? Pilot bushing?

 

It may possibly just be the new clutch friction plate. They can need some use before they break in and smooth out.

Under that theory the noise stops in neutral, because the driven plate is turning with the friction plate, due to drag. In gear, the driven plate stops coasting and the friction disc is rubbing noisily. Just an idea.

 

I just put a new clutch and pressure plate in mine and had a wierd noise also. Thought it was the throw out bearing till opened inspection plate on top of bell housing. I was what Petel was saying, clutch not broke in and was vibrating when clutch was depressed. It makes the noise when in gear because clutch is stopped then when in neutral it is free to spin and not make the noise. Let the clutch out and clutch is tight, no noise.

 

OK, well you guys are helping relieve some panic. Everything inside the bellhousing is brand new except for the flywheel so it could just need broken in. I may go ahead and pull the transmission back off anyway just to check that I tightened everything -- a good sanity check.

 

did it make those sounds before you changed the clutch?

 

It barely ran when I got it and that's when I tore it down for complete frame up restoration. So I'm not sure if it did or not. One other variable that I forgot to mention, though, is that I took it in to a garage last Friday to have it aligned. I asked them to check the brake and clutch adjustments while it was there. They said they adjusted the clutch but they weren't sure why it was engaging so high on the pedal travel. I didn't notice this noise before they adjusted it but I had only driven it a few miles before then.

 

I'm at work today and thinking about this problem (everyone thinks about Jeep problems while at work, right?) and the more I think about it the more I think I am looking at two separate issues.

Problem #1 is the clutch is not fully disengaging, I think that is a given. If it was fully disengaging then it wouldn't matter if the transmission was in gear or not.

Problem #2 is something in the transfer case. The fact that I can have the transmission in gear but the transfer case in neutral and the noise goes away tells me that the noise is coming from the transfer case final drive shaft. Neutralize it, noise goes away, engage it and it makes a bad sound. My theory now is that the clutch not fully disengaging is causing a vibration on this shaft that doesn't happen during full load.

So my final conclusion is that I have some sort of shim or bearing problem in the transfer case that allows a transfer of vibration from an on-again-off-again clutch disengagement caused by a clutch that has not yet been broken in.

Does this make sense?

 

The clutch should begin to engage at 2+/- inches from the floor and have about 1-1 1/2" free-play at the top.

 

I still think you have this wrong.

This is all based on your statement in your first post about being not moving, but the clutch in. In this condition, the tranny/xfr case drive shaft, and diff all combine to keep the clutch disk from rotating. By having the clutch pedal pushed in, the flywheel and pressure plate are rotating around the clutch disk, and that is where I suspect the viberation is coming from.

When you put the tranny, OR the xfr case in neutral, the clutch disk can spin, and the noise/viberation between the clutch disk and flywheel/pressure plate does not happen.

Adjust the clutch linkage so it releases sooner when pushing the pedal in.

Also, in another thread you mentioned that you used an orbital sander to surface the flywheel, instead of having a professional shop do a blanchard grind-----this may be a contributing factor.

 

Mike,

It just doesn't make sense to me why I can have the transmission in gear and the transfer case in neutral and the noise disappears. That is the part that baffles me the most and is why I keep thinking I have a transfer case problem. But I don't know because I do not have any abnormal sounds from driving. I will fiddle with the clutch adjustments and report back.

On the flywheel resurfacing, I used a sander with fine grit paper to essentially remove the surface rust and sort of scuff the surface up a little. I didn't use enough pressure to do any resurfacing and that wasn't my intention. Granted, I did not have the flywheel checked at a machine shop but I don't get any clutch chatter so I don't think it is out of whack.

 

When you are stopped, and the trans and xfr case are in gear, nothing inside either of them is turning. If all the internal parst are at rest, how can they be making noise??

But, the engine is turning, and the disconnect from that rotation is at the clutch. This is why I think the noise is in the clutch assembly.

Try letting the clutch out with the tranny in gear, and the xfr case in neutral----------the Jeep will not move, but the internals are rotating. I'll bet there is no noise.

 

This says a lot.

Also, go back and reread posts 6 and 7.

You may have a mismatched bunch of parts in the clutch release mechanism, thus requiring a different adjustment than normal. Put the adjustment back where you had it, see if that makes it better.

 

Correct, no noise. I re-read posts 6 and 7 as you suggested and I think I'm beginning to understand. It takes me a while to wrap my brain around things sometimes.

Thank you very much for your help and patience. I will check the clutch adjustments and see what variables change.

 

I noticed today that it doesn't act up when cold, it is only after I run it for a while. I was also able to reproduce it with the transfer case in neutral and the transmission in gear -- something it didn't seem to do last night. So I guess it does look more and more like a clutch issue. I guess that's a good thing.

 

Was at your website and what a project to be proud of. Hats off and hope that all the little quirks get worked out. Looks like you have the patience to get there. Loretta is beautiful.

Back to the problem... I have a 63 f134 with the t90 and I replaced the clutch, pressure plate and had flywheel turned. It has the 9.25 heavy duty clutch in it and the noise was there for about 3 to 4 weeks basically till got clutch wore in. Havn't had noise since.