Hey all,

I've noticed a thick film of oil on my Muncie tranmission case. It collects and shows forming dropplets at low points on the box. Inspection of the sides shows that it is on driver's side and not the passenger's.

The weird thing is that I haven't really been seeing drips on the garge floor after the car sits for a couple of days. I've checked oil level and haven't needed to add any oil.

On a related note: I get some heavy vibration through the shifter between 65 and 75 and then again at 85 and up. I've replaced the diff universal joint and have gotten an alignment. But it is still there.

I'm thinking that one possibility is that the seals at the shifter forks are leaking (film only on driver's side).

does this sound like a reasonable diagnosis? could the shifter vibration be causing this leak? if so, how easy is it to change these seals with the tranny still on the car?

could it be an engine oil leak? I do go through alot of engine oil (1 quart every 125+ miles.) any ideas about an engine oil leak that would leave as film as described above and NOT on the floor?

does anyone have a better idea of what may be causing this?

It sounds like the shift shaft seals are the culprit, but my question is why is it vibrating so much? Check u-joints and tranny and motor mounts.

To check motor mounts, hood up, front wheels chocked, put vehicle in a forward gear with foot on the brake and hit the gas pedal and see if the engine lifts up, then do the same in reverse, but move wheel chocks to rear of front wheels. To check trans mount, get under the vehicle and see if the trans lifts up, or moves side to side.

Muncie transmission cases sometimes have "porosity" leaks. If none of your seals or gaskets are leaking this could be the cause.

[This message has been edited by JERRY66SS (edited 11-18-98).]

First thing to do is get under there and wipe everything down. Drive a couple days and take a look. Could be valve cover, intake manifold, oil sender, etc. on engine - or front seal, sideplate seals on tranny. Seals are readily avail. at most NAPA parts shops. That type vibration is really a bear to find and fix sometimes. Could be engine, flywheel, pilot bushing, tailshaft bushing, driveline. tom

Hmmm. I think the vibration is due to the slipped harmonic balancer you have, and some kid named Joey is going to rebuild your crashbox in the future. I can see everything.... The future looks bright ahead..... http://www.chevelles.com/forum/smile.gifBTW, hows the secondaries opening for ya?

Mike, I rebuild Muncies blindfolded. If your noise is like a buzzing vibration coming up through the shifter, I can almost guarantee that it is caused by a worn and or pitted main bearing at the back of the main case. This is very typical of well used Muncies. The only way to fix it is to tear it down and replace the bearing. And if you have it torn down, you might as well go through it. Muncies DO NOT require a rocket science degree! If you do have someone rebuild it for you, make damn sure they are VERY knowlegable about Muncies. Over the years I have learned many pointers about how to save a tired Muncie. And no, you cannot change the shifter shaft seals with the tranny in the car. With a lot of effort you can remove the side cover and change those with the tranny still in the car, but you cannot change the reverse shifter shaft without removing the tail housing. Call, email or whatever and I will tell you anything you need to know about rebuilding a Muncie.

DZAUTO,

Thanks for you reply. The vibration is like a buzz at speed which increases in amplitude with speed independant of the engine (i.e. doing 90 and push the clutch it's still there.)

My plan is to do the rebuild myself with the help of my good friend "bitchincamaro" aka JoeyT aka Toecutter. I have a complete rebuild kit that I got through Medatronics Corp in Fla. The kit looks like the same as offered by Year One. I think that Medatronics are the "source" for said kit. It includes all bearings, seals, synchos, etc for the job. Any tips you care to enpart? Do I need a special wrench for that nut on the input shaft?

At the same time I'm going to address my significant oil loss, which I think is caused by the rear main seal. Perfect time to do so. Thanks again for your reply.

When you remove the rear seal you should also replace the rear bushing. To remove it, you find some to drive down into the tail housing and install the nwe one by using a block of wood to drive it in until the block contacts the end of the tail housing then use something like a BIG socket do drive the rest of the way. IT IS VERY IMPORTANT that the front end of the cluster gear is a very tight fit in its hole in the front of the case. When the shaft is in tight, it SHOULD NOT protrude beyond the front surface of the case (the front of the shaft is a taper fit to keep the shaft from protruding and also serves as an oil seal). If it protrudes when you instal it, the back surface of the bell housing will push it back into the tranny case and you have an oil leak, among other things. You can fix this your self, its fairly simple. The fix MUST be done when the main case is empty. If you need details, call me: Tom Parsons 405-745-8383 anytime.

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