My 1994 Jimmy was in a rear end accident and all the transmisson fuel leaked out. I aws able to operate the transmisson after the wreck so I think it is the rear seal. What's the procedure for replacing...
Replacing the rear transmission seal involves removing the driveshaft for access.
Depending on the ground clearance of the vehicle, you may need to raise the rear of the car and support it on safety stands. Please make sure that the car is completely stable before continuing any work if you do need to raise it.
You will need some tools, mainly the correct sized wrenches or socket set to fit the bolts and nuts that must be removed. A large screwdriver will come in handy, a hammer, a marking tool, tape and if the transmission has fluid in it, you should have a container for catching any fluid that will leak out. You will of course need the correct seal for the back of the transmission and transmission fluid of the correct type to replace any that leaks out during this procedure.
The first step is to mark the location of the driveshaft in relation to the connection on the rear end. Using chalk or some type of marker, make a mark on the driveshaft and also the pinion yoke. This yoke is the part that the driveshaft universal joint is bolted too. Once that is done, you can start unbolting the caps or straps that are holding the universal joint to the rear end. With those connections out of the way, gently use the screwdriver to lever the driveshaft forward far enough for the universal to clear the pinion yoke. Now drop the back of the driveshaft down and using the tape, wrap a few runs around the universal joint and its caps. This will keep them from falling off and getting dirt in the caps which can damage the inner bearings.
Now you are ready to remove the driveshaft. While not very heavy, it can be a bit tough to handle while laying under a vehicle. Take your time and simply pull the driveshaft backwards until the front input shaft slides out of the transmission. With the container in place, any fluid that escapes should be caught. You can now lay the driveshaft to the side, but place a rag underneath the input shaft to minimize any dirt being picked up.
You can now remove the rear seal from the transmission. Normally using the screwdriver and being careful to only pry on the seal, you should be able to lever out the seal. You may need to work your way around the seal, levering it out a little bit at a time, but it will come out. With the seal out, wipe the seal area to remove any dirt, fluid, etc. I prefer to put a touch of sealant around the outside circumference of the seal (painted area), but it is not mandatory, just a little insurance. Using the hammer, carefully tap the seal back into place. Take your time and do not damage or bend the rubber seal area.
Now you can put the driveshaft back in, but here are a couple of tips. First, place the gear selector in neutral, this will help you line up the back of the driveshaft with the marks that you made during removal. Second, wipe the rubber of the seal with just a touch of transmission fluid to lubricate it.
Once you have the driveshaft input shaft back in the transmission, you will need to line up your marks on the driveshaft and rear pinion yoke. You should be able to rotate the driveshaft as needed, then remove the tape and push the driveshaft back in place. Replace the caps or straps, start the bolts, then put the gear selector back in park. Now you can tighten down the bolts or nuts as required.
Safely lower the car back to the ground, top up the transmission fluid as required and you are finished.
Please let me know if you have any additional questions concerning this issue.
May 07, 2010 |
1994 GMC Jimmy