knocking noise in transmission

hornet7288

Member
Oct 18, 2005
260
0
16
36
Savannah, GA
Yes, I know what you're all thinking...rodknock. But hear me out...

So a little background on the car. It's a 1989 with a swapped in/rebuilt 7mgte. Mods include full 3 inch exhaust with open divorced downpipe, AFPR, walbro fuel pump, FCON with GCC and VPC AND a ebc. The clutch started slipping with that setup which was no surprise considering the clutch in it was from the old nonturbo engine. Got a new clutch (southbend clutch can't remember the model number) and installed it. While it was all apart I had the flywheel resurfaced. Since the pilot and throwout bearings were both replaced when I did the swap 3 years/10k miles ago I decided not to replace either when I had the transmission off. Here I am approximately 1000 miles after the clutch install...started doing a few pulls today to get a rough tune with the GCC and VPC. After a couple of pulls I noticed a faint knocking sound. My heart sunk as I thought it was rodknock. It was happening around 2k rpms at its loudest, but seemed to quiet down in the higher RPM's. I didn't hear anything in neutral. However once I got it to the garage while the car was running, I noticed a "clunk" or knock sound when the clutch was almost fully depressed. Along with the noise I could feel the pedal give a little when I heard the sound. Not tons, but it was enough that I could notice it. Once again, when I rev the car in neutral I could hear the sound mostly at 2k rpm's.

So I went ahead and jacked up the front end and crawled underneath dreading that I would find that everything was fine and that this noise I was hearing was rodknock. Once I crawled underneath I found that the clutch fork seemed fairly loose. It would not move in and out, but I could push it with my finger up and down which would cause a fairly loud knocking sound. A few questions:

1. how freely is the clutch fork supposed to move up and down? If you push the bottom of the fork (facing the ground) up with your finger, how much should it move?

2. Could there be something wrong with the clutch/pressure plate/flywheel?

3. Is it possible the throwout bearing is jacked? I remember having a little difficulty figuring out how to attach the throwout bearing to the clutch fork, but I believe I got it right?

Anyway thanks for the help...like I said it SOUNDS like rodknock, but with a new engine, how religious I am about changing the oil/checking the oil, and having just replaced the clutch I really think something is up with the clutch. If it were rodknock I find it really suspicious that it starts knocking and this clutch problem both start at the exact same time. I HOPE my luck isn't that bad haha.
 

hornet7288

Member
Oct 18, 2005
260
0
16
36
Savannah, GA
A little more information...I noticed the noise after a good long drive with fairly hard driving. Like I said...I was trying to dial in the GCC.

Just went out to the garage a little while ago and fired her back up. I hear absolutely no noise now. No noise at idle (even though there wasn't really before at idle), no noise at higher RPM's and no noise when pushing the clutch in and letting it out. Are there any heat related clutch/flywheel/pressure plate issues that would cause a knocking sound under higher heat conditions and no noise after cooling down?

BTW the trans is a w58.

Thanks
 
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