OK... Now what's wrong?

Hello all,

Just finished a rebuild of my T-90 transmission and Dana 18 Transfer case last week. I did it at a Jeep shop with a mechanic looking over my shoulder and so I had lot's of confidence in the job when I was done.
Took it home and put it in. A little trouble with the clutch getting in aligned to fit... but after about 30 minutes it slipped right in flush with the bell housing... I've been driving it for about 150 miles... shifts a little stiff but otherwise no problems and quiet. Yesterday I took the wife for a ride of about 30 miles when something happened suddenly.... something started with some loss of power and vibration... Engine still running( sounds good at idle but if you increase RPM's (in neutral) sounds rough and somethings wrong... I thought at first my Tranny and T-case job went bad but I'm not so sure now. I wonder about the engine or the clutch.
I checked the compression this a.m.... cylinder 1 at 93, cylinder 2 at 115, cylinder 3 at 110, and cylinder 4 at 115. Oil level good (and clean)
Antifreeze level good (and fresh).
Engine temp yesterday started to get a little on the warm side before this happened. (gauge was between 3/4 and pegged) And it was just an easy 30-35 mph drive on pavement!

I thought if it threw a rod, piston or valve I would have zero compression in one cylinder.... right ?????

In neutral coasting there is no real noise or vibration from tranny or t-case.

Any thoughts???

Thanks in advance.....:?

Jim

 

I dont want to point you in the wrong direction, but could the timing be out?
The vibration part has me confused though.

 

I have'nt checked that yet but I will tonight!

 

Just a guess but I'll say fuel system. Maybe knocked some rust loose when putting tranny in? Pull the fuel line at the carb and check for good supply,maybe a bit of junk found its way into the carb?. Plugged fuel filter will let you idle but starve the motor under load. Vibration due to misfire??? Good luck.

 

Nope, the front bearing retainer gasket is clear of the oil hole... made sure of this when installing... thanks though!

 

The manual calls for compression between 120 and 130.... it's not a new engine but what do you guys think of the compression numbers?

 

All of the manuals I read say the lowest should be at east 80% of the highest. At 115 that would 92 so you are good there although all are low. Put a teaspoon of oil down each sparkplug hole one at a time and check again. If numbers go up its rings, if the same then look at valve train.

 

I'm thinking fuel as well. vibration could be from misfire. Need some more investigation...

 

Vapor lock? Condensation in the tank? Was it a cold night & a very warm day w/ the tank half-full?

 

I'd check the plugs. If you have how do they look? The points ok?
Basic things but important.

 

Tonight I'll check plugs, points, timing and re check compression. I'll pop the top on the tranny to see if anythings a miss there as well. T-case shifts nice all round.

Regarding Vapor lock... it was cool night warm day scenario but full fuel and I really don't get a sense that it is a fuel type problem. but I'll keep it in mind.

To describe the incident further.... I was going down an incline on paved road in 3rd gear at 35mph running fine but maybe a bit warm, suddenly as starting up the opposite incline(accelerating) a loss of power and metalic grinding noise with vibration... you could obviously tell something was wrong... took out of gear and let the engine idle... sound improved but immediately returns if engine rpms increased (clutch in , still, tranny in neutral. Oil pressure light did not come on. No leaks I can see.

Had to nurse it home. 5mph at idle speed any time the accelerator was touched she'd make some unpleasant noises(metalic sounding)


THANKS EVERYONE FOR YOUR RESPONSES!

JIM

 

Metalic noises are not good.
Think you can forget checking the timing.
What abot the rest of the drive train? Wheel bearings etc?

 

I hate to ask, but you did put oil in the tranny, right? I'm sure it wouldn't be the first time somebody forgot. Actually sounds like something I would do.

 

Had a clutch go bad in my '64 Chevy 1/2 ton one time. Spring came loose and made an awful racket, but clutch wasn't entirely functional after that, so not same symptoms you describe. Still, may want to check inside the bell housing mebbe?

 

Yep, I sure did... but it isn't leaking either so maybe it was dry! What's the saying... if it aint leaking, it must be empty ...

But I must say that is something I could see myself doing!

 

I'll check the bell housing!!! I'd rather have the clutch go bad than the engine!

 

did you check the balance weights on the drive shaft? would check the ujoints on the driveshafts as well.

 

Last night I took my stethoscope to the engine ... I couldn't find any area on the engine block making any more noise than any other!

I took off the shift tower to have a look... everything looks good inside the tranny... and yes there is oil in there. R)

The noise/vibration in question seems to be coming from inside the bell housing... although I can't see anything wrong with the clutch looking into the portal in the bell housing... and the clutch seems to work right... The noise and vibration though seem to change a bit when the clutch pedal is depressed (improves)

My plan is to remove t-case/ tranny and bell housing as one unit and take a good close look at the clutch... maybe just replace it while I'm there.

When I started the project to rebuild the t-case, The transmission shaft came apart and I lost the bearings on the main shaft so I had to rebuild the tranny... any way the tranny got a bit stuck coming out of the clutch... I wonder if something got messed up with the clutch then???

My engine just starts and sounds too good at idle to think it's the engine.. but then again I'm a P.A. not a professional mechanic!