bigwave

OK, I found me a used trany with 66k miles on it. How hard is it to replace? I have access to a lift and a trans-jack, basically a full service auto garage less the mechanic.
I'm pretty handy and have replace manual tranys and clutches. Are there any tricks I need to watch for other than making certain the torque converter is lines up? It is 4x4 so I do have to work with the t-case also. Has anyone done a write up? I've searched but no luck. Thanks

dave1123

With the lift and trans jack, you can pull the trans with the t-case attached, but be careful because of the off-center weight. The same thing goes for handling the t-case alone. The problem with the t-case is there is really no center of balance to jack on. If you pull them together, DO NOT use the trans pan to jack against.

Remove the exhaust pipe, starter and the crossmember, t-case linkage also, lower it down and remove the top bellhousing bolts first. Disconnect all the electrics and cables. Pay close attention to the CPS harness. Remove the bellhousing inspection cover and remove the torque converter drive bolts if you haven't already done so. Remove and install the trans with the torque converter on the trans, not attached to the engine. It's a good idea to bolt a small piece of steel to one of the bellhousing bolts to retain the converter so you don't lose it when it comes out. Watch the dipstick tube when lowering the trans. I've broken them off before.

Don't lower the trans too much when taking out the bolts because of the battery cables, radiator hoses and fan. I've pulled many GM trannys out leaving the engine balanced on the mounts, but IDK about the I6 if it's safe to do that. When I did the trans in my '87 Chevy 4x4, I pulled the t-case first because I'd never done it before and I was laying on my back under it. I built a cradle for the t-case out of pieces of steel angle and threaded rod to bolt to my floor jack. Everything was fine until I went to pull it out from under and the whole jack and t-case rolled over! Damn!

When I went to re-install the trans after I rebuilt it, I decided to install the dipstick last. Having never done a jeep, IDK how they are, but the GM transmissions have a hole that's bored into the case with sharp edges. You have to install the rubber grommet into the case first, then slip the tube into the grommet. I couldn't get the grommet to go into the case when it was already on the tube. A little silicon grease works well.

If you run into problems, PM me and I can probably help. I'm usually on the site every day.

OH! I almost forgot! When you bolt it up, don't draw it up tight before you make sure the converter spins freely. It's got to be engaged with the pump drive or you can damage the pump. When it's tight on the bellhousing, there should be a little clearance between the converter and the drive plate. A good way to check if it's engaged is to measure the distance from the engine block to the back of the drive plate and make sure there is AT LEAST that distance between the front of the trans case and the converter drive bolt bosses.

Again I forgot! Remove the trans cooling lines!

bigwave

Now, what about a transmission flush. I've read a few places saying to make certain and do a transmission flush before installing a new one or you're allowing all the old junk to keep circulating. I did just replace the trans-filter on this one a few months ago hoping that was part or all of the problem. I've seen a few people (youtube) unhook the cooler line and run fluid through until it turns clean. What do you think?

dave1123

When you pull the old one out, The only fluid you've got left is what's in the radiator cooling coil. Just flush that out with LOW air pressure. Be sure to clean out the aux cooler if you have one.

Remember there is about 5 qts of fluid in the converter so put a pan under it when you pull it off the trans. I didn't think I needed to tell you to drain the trans pan before you pulled it.

bigwave

The more I think about it; I did just put a new filter on the darn thing about 4000 miles ago hoping to help the issue. I left it set for a few hours with pan off so allot of the fluid has very recently been drained. When I look on the dip stick it is very bright red and looks like new. I think, by the way the filter looked the PO had just done the same thing. As for the drain pan, why on earth they did not put a drain plug on the pan is beyond me...... Dumb. They know the filter has to be checked every xxxxx miles.

dave1123

Why no drain plug? Cost of production, of course! Question. Was there a magnet in the pan? GM puts a magnet in the pan so you can tell if the clutch driven plates are wearing. IDK about jeep. Seems like a good idea to me.

My WJ has 163K on her and has had 2 T-Tech fluid changes that were on the maintenance records I got with it. The T-Tech uses a cylinder to push out the old fluid replacing it with new at the same time. That means to me, it's probably got the original filter in it. I'll change that in the spring. AND add a magnet if it doesn't have one.

Also, I've been told Mopar has a re-usable pan gasket that is a sandwich of steel and neoprene. I'm going to check that out. Knowing Mopar, it's probably $50!