Exploratory tranny-ectomy with clutch biopsy

After draping and prepping the patient, (a 1961 CJ5, F-134, T-90, and Dana 18) I made the initial incision.... er the intial bolt removal.... for an exploratory tranny-ectomy with clutch biopsy and pilot bearing replacement.

History of present illness shows that 3 weeks prior the patient had undergone a prior exploratory transfer case disassembly to repair a wore intermediate shaft... During the procedure, a complication occured, the front half of the main shaft of the transmission separated from the rear half causing a number of needle bearings to be dislodged and travel as transmision emboli to the bottom of the tranny case ... It seems the surgeon was a rookie

This required extension of the surgery to involve reconstruction of the transmission in toto.
After consultation with a local jeep custom 4X4 guy an arrangement for a surgical assistant was made. (said assistant looked over the shoulder of said surgeon (rookie) ) after rebuild... the entire unit was felt by both to be solid, tight and good.
Implantation of the repaired unit was performed without significant complication. However, the vehicle was gently driven 150miles when suddenly and unexpectedly the patient began vibrating and emitting a noise from the bell housing region, which was made worse with acceleration and with downshifting. the vibration and noise all but ceased at idle. and increased again in proportion to RPM's. Additionally the noise and vibration would change with clutch pedal manipulation:?

Current procedure involved removing the transmission. inspecting:?
removal of clutch and inspecting the clutch, pilot bushing, and fly wheel
after removing the components the rookie surgeon , is unable to identify a single certain etiology for the symptoms mentioned.
Surgeon therefore is consulting numerous experts (early cj5 forum) for second, third, fourth and gazzillionth opinions.
Possible problems -- 1. some play at front mainshaft bearing.
2. some play in clutch disc assembly (small amount) normal???
3. Likely too much end play at fly wheel.... estimate one sixteenth inch end play.

 

How old is the clutch? To my novice eyes, that pressure plate and flywheel look rough (discoloration), but that's just what I see in the picture.....

Don't worry, most of us are rookies once in a while!

 

ditto on the clutch
p/plate shows signs of slippage
were all bolts tight, none found loose during disassembly ?

 

:iagree:
The flywheel and pressure plate surface look like crap.

 

Yeah, they look like crap, but I've seen much worse....the one that came out of my F250 looked worse, but it still worked fine. 1/16" of shaft endplay sounds like a lot for some reason...maybe look at that... Good luck!

 

Might as well replace clutch and preassure plate, machine flywheel while it is out...

 

I think I'll replace clutch entirely and machine flywheel. Pilot bushing which was my first suspect seems fine.
The front bearing on the tranny seems a little sloppy, I wonder if it crapped out... couldn't be parts jealousy since it was brand new!

The clutch has worked great since I have owned it... about 7 years and 2000 miles... I have no Idea when it was replaced or serviced if ever.
The engine is the same... seems to work fine, but no clue if rebuilt or not. No loose parts found during dissection!

Flywheel end play seems like alot. I guess this translates to crankshaft end play... but how serious is that if the motor runs ok?

 

I wanted to post more pics of the tranny to go with this post so here goes!

 

When you have that flywheel resurfaced. Make sure you torque the bolts.

Don't ask how I know.

 

the only other oddity I notice in the pics of the flywheel is it appears the tapered dowel pins have been replaced with larger bolts, possibly larger holes drilled thru the crankshaft/flywheel. All of the nuts/bolts should be the same thread size, and its obvious that 2 of the nuts pictured are much larger than the other 4.
This probably has nothing to do with your problem, as long as the heads of those 2 larger bolts aren't hitting/rubbing up against on the backside of the flywheel. I only mention this as a curiosity as you mention a possible crankshaft end play problem as well.

 

Hmmm?? That's interesting

 

agreed on the resurfacing problem...the flywheel and clutch both look like they are glazing.

 

There is suppose to be a large snap ring around the outside of the bearing. It might be the photo, but I don't see the snap ring on my monitor.
If you have a 1/16" of crankshaft endplay your crankshaft thrust bearing is wore out.

 

There is a snap ring around the bearing. It's not the clearest photo, but it's there.

If the crankshaft thrust bearing is worn, is that a whole engine rebuild?

 

Jim, mine is the same way. I wouldn't sweat this other than being sure that they are torqued as per the FSM.

 

I realize that Thad
just wanted him to be aware and make sure there isn't a stack of washers or something else on the other side of that flywheel from some PO that's not visible, that's all

 

Thanks guys, I will remove it tonight and have it re surfaced tomorrow, will put pilot bushing in at the same time.

Regarding the possible stack of washers or something... what might that be?

 

I was referring to what the PO might have done
if he didn't use the right length bolt, he could have added spacers/washers under the bolt
that might cause the head of the bolt to hit depending on your crankshaft end play problem
just something to look at while it's apart, that's all !
you never know what you might find from a previous owner

 

The service manual says that when you install a new crankshaft or flywheel you can use Flywheel Dowel Bolt Installing Tool Kit W-231, whatever that is, and drill and ream out the tapered holes. Then install "two special flywheel bolts." Perhaps that's what has happened here.

Kevin

 

Ok! understood. Thanks!