Help diagnose my knock...

[Jeffncs]

I recently installed a new Luk clutch kit into my 82 CJ7. It’s a straight 6 and a T5 manual trans.

Scenario:
I have maybe 50 miles on the new clutch and it’s been perfect...until this afternoon. After flushing my cooling system, I took it for a test drive to help drain the water from the floors (washed it and rinsed out some dirt/mud from interior).

I came to a complete stop at a stop sign on a slight hill. I accelerated moderately from the stop as I turned left and heard a pop and subsequent knocking in time it’s the engine rpm. I immediately thought driveshaft as I felt the noise in the shifter.

Some additional details / observations:
Knock is present while trans is in N
Knock is present while clutch pedal is released
Knock is NOT present while clutch pedal depressed
Knock stays in tune with the engine rpm (speeds up/slows with engine speed)
Trans seems to function with with shifts with no impact on the knock
T-case works fine too with no impact on knock

My initial fear after confirming the driveshafts weren’t the source was engine failure. Oil pressure is good and engine runs at usual temp with no oil in the coolant. The intermittent sound with clutch situation rules the engine put in my opinion.

Clearly there’s something going on with the rotating assembly... I just have no ideas yet and really don’t want to pull the trans until I know if I should also be looking for a replacement engine (current engine has 185k and I have a line on a running, low mileage 4.0 with EFI).

Trying to get this thing going as I was hoping for a fall beach trip and URE. This is a major curve that I’ve never run into with a seemingly successful clutch job?!?!?!

I torqued everything and double checked before buttoning things up! I also used blue loctite on the flywheel and pressure plate bolts.

I’ll ask for advice on the 4.2->4.0 swap in a separate thread...after some add’l reading.

Thanks in advance!!

 

[Jeffncs]

I’m reading that it’s likely an input bearing in the trans based on the presence / absence of the noise during clutch operation.

Any trans rebuilders around Wake Forest?

 

[Jeffncs]

I had my wife operate the clutch while under the Jeep and sure enough I see the HB shift forward with the first clutch press and maybe with the second then it stops. If I manually turn the crank with the HB bolt, the HB will shift with the next clutch presses.

Any way to check thrust/main bearing tolerances with the engine still in the Jeep?

Another new issue is that the screaming starter is back and just as loud as before. It was quiet and “normal” until this issue reared it’s head again.

Theorizing a bit here... if the crank is shifted forward 1/16” or so, would that also create the screaming starter along with the engine-timed knock?

I pulled the inspection plate, shift fork boot and starter. Using a mirror and a bright light, I can’t see anything out of place. The pressure plate appears to be clearing the bell housing and the input shaft and all parts appear to be where they belong....

I’m debating a 4.0 swap with fuel injection with pulling this trans again.... I may as well go all in to maybe avoid doing it again this winter (was already planning to do it eventually).