Loud rattle and marble sound coming from bellhousing after clutch/flywheel job
 

First post on here!

I have an 88 22RE 4wd pickup with a w56 tranny. Did a top end rebuild and full gasket overhaul last November, and had a bad leak from the rear main after the rebuild so I pulled the tranny again a month ago to sleeve the crank due to a groove and decided to replace the clutch/flywheel/pilot/TO while it was off. I put everything back together to make a trip up to Oregon (from Tahoe) and had a bit of a crunch to the pedal, but no issues besides that. I got 1300 miles into my trip and started noticing an erratic idle (which could be a separate issue but started 400 mi before I broke down) and loud whirring/ringing sounds that sounded like TO and pilot bearing noises. After 400 miles of this, I noticed the shifting became more difficult and at a point went to put my truck in reverse, and everything locked up. There was a loud "thud" everytime I tried to start it, and it was unable to be cranked in either direction from the front pulley manually. Obviously, I assumed the engine had seized or tranny had blown, and I towed it home.

Flash forward a bit and I finally got around to dropping the transmission again. I noticed the plate between the back of the block and the flywheel was completely loose, and the two small bolts were almost shredded. Not sure how that happened, but as soon as I took the clutch assembly and flywheel off the engine cranked again. I can only imagine that the loose backing plate bolt has somehow kept the flywheel from spinning, but that's only a guess at this point.

I reinstalled the backing plate, and the flywheel and clutch, torqued and with loctite. I replaced the shift fork, collar clips, and the throwout bearing again in case it was a bad part out of the store. made sure everything looked smooth and put it all back together. Drove it for 100 miles but there is now a noticeable knocking/ticking coming from the bellhousing, and a marble sound from the transmission itself. I bought a stethoscope to try and narrow it down and although it's not clear where it's coming from when I listen to the shift fork it is super loud, and also on the bellhousing area, and lightly ticks on the length of the block but nothing loud. I can peek in there and see that the backing plate bolts have clearance so that's not the issue this time.

I noticed when the transmission was out of the truck that the input shaft had a bit of side to side play, but looked around the forums and didn't seem to think it was such a big deal. Seems the truck is running at higher RPMs.. but the idle is still erratic as it has been many times at sea level before. Sometimes surges in neutral unless I go into neutral from a higher RPM or tap on the gas pedal. Could be a separate issue, maybe IACV/TPS I honestly have no idea.

Could it be that the transmission input shaft has too much play because of a bad bearing?
Flywheel problems?
Just an engine knock? The bottom end needs a rebuild and is burning a lot of oil as it is.
Is everything just about to blow up on me?

I have now dropped and installed my tranny 4 times in the last year. That is no easy task for a 130 lb girl and I would really like to not have to keep doing it. Any help is appreciated

Well, that's quite the adventure. I had (I assume) a similar ticking sound coming from my bell housing area right before the rod went through the block. I thought it was the clutch coming apart until I saw the hole in the block. It's hard to tell what is really happening through your description though.
When there's noise coming from the bell housing, I don't trust it now.

• Have you drained the oil to see if any bits of bearing are in the oil?
• Do you see any new metal shavings near the backing plate/bell housing? I suspect something might be out of whack you didn't notice from its last bolt excursion.
• May sound silly but is the clutch friction plate and throwout bearing on the correct direction?
• Were your pressure plate fingers all in good condition?

Best of luck,
A 120 lb guy

Get a mechanics stethoscope and give the motor and trans a close listen. This will help you at least localize where the issue

On some vehicles (I don't know about this one) you can take off the starter and get in there with a borescope to look around. I'd do that if you could, and see if there's anything that appears out of sorts. I recently (different kind of truck) lost a very old clutch disc due to overspeed, and a quick look in the starter opening would have solved the mystery of the odd sounds pretty quickly.

No shavings in the oil
clutch and TO both on the right way
After I replaced it after 300 mi there was some wear on the front of the fingers where it meets the TO bearing, but nothing dramatic

I do have the stethoscope but having trouble distinguishing anything on any part of the engine besides sloshing sounds. No distinguishable knocks with the stethoscope, are they supposed to be loud and apparent if there is a rod knock or something to do with the bottom end? The transmission fork does rattle a bit. lots of noise coming from valve cover bolts (but not valve cover itself)

What should I look for in there with a borescope? They're pretty pricey, so if I have to get one I will.

Could there be an issue with the input shaft bearing of the tranny going out, making the input shaft have too much play?

1) With engine running, truck not moving and clutch depressed, do you hear the rattle?

2) With the transmission in neutral, if you slowly release the clutch, then what happens to the noise?

If you hear the noise during step 1, then clutch is depressed and tranny input shaft is not spinning, so noise here would indicate something maybe pressure plate or flywheel backing plate related.

If you only hear it in step 2, could be the input bearing maybe, could be throwout bearing, or clutch fork related.

If you don't hear the noise in either of those 2, then when exactly do you hear it? Is it only while vehicle is in gear and moving?


And by the way, I don't know that you need a borescope yet, but they have pretty inexpensive ones on Amazon that attach to your cell phone.

Last time I went to Oreilly’s I saw a borescope they had for loaner tools.

you can check the throw-out bearing with a borescope coming from the clutch fork opening.