: Rear Main Seal Installer



Lawrence
02-21-04, 01:14 PM
Anyone know where I can get a rear main seal install tool? 1994 STS.

Is this the only way to install the seal?

BeelzeBob
02-21-04, 11:16 PM
Anyone know where I can get a rear main seal install tool? 1994 STS.

Is this the only way to install the seal?

If the rear main seal is not leaking I would not take it out and replace it. You can cause more problems with the interface with the side seals in the lower crankcase joint where they intersect the rear main.... The rear main will last a long long time so if it is OK it is liable to stay that way for quite awhile.

If you are going to pull the lower end down like you mention in your other post you can replace the rear main seal without the special installer. The lower crank case will split at the crank centerline exposing the rear main seal channel. When you reassemble the lower crank case, place the new rear main seal into the rear main seal bore or channel in the block and then install the lower crank case. It is actually better to do this as you can add a small dab of RTV to the intersection of the lower crank case split line seals where they contact the rear main this way.

The rear main seal has been superceded by a new part number that is a wider seal in the area where the seal intersects the block. If you just want to "update" the seal then that is pointless as the actual seal surface is the same...just the land is wider against the block. If it is not seeping then the wider land is pointless in your case.

Lawrence
02-22-04, 05:45 PM
Thanks bbobynski. As in that other post, the area is just so wet I can be sure if it is leaking or not.

Is there something here I am missing as far as diagnosis?

BeelzeBob
02-22-04, 09:17 PM
Thanks bbobynski. As in that other post, the area is just so wet I can be sure if it is leaking or not.

Is there something here I am missing as far as diagnosis?

No, I don't think so. The diagnosis of the lower end leaking really needed to be done in the car with the engine running. Putting dye in the oil would have positively allowed an ID of any potential lower end leaks then...but...impossible now.

If you suspect lower end leaks or the area is wet I would tend to agree with you and separate the lower end and reseal it just to be sure. Everything is pretty much reuseable down there anyway...so it is just time to take it apart and clean it up and put it back together. Just torque the main bolts in the correct sequence...that is important.

When you are ready to install the lower crankcase, put the anaerobic sealant on the block/LCC surface (GM has a specific PN sealer but the Loctite "gasket eliminator" product is pretty close....), slide the new rear main seal onto the crank and into the seal bore of the block and then install the lower crankcase thus "trapping" the rear main seal. Add a tiny dab of RTV to the immediate area of the rear main seal where the side seals of the block/LCC touch the seal for insurance. Just make positively sure that the rear main is purfectly straight on the crank...that is the only hazard of not using the special tool to press it in after the block is assembled.

Lawrence
02-23-04, 12:36 PM
bbobynski.........I would expect that the OEM case half seal is used in addtion to the anerobic sealer. Is this correct?

Thanks,
Lawrence

BeelzeBob
02-23-04, 02:32 PM
bbobynski.........I would expect that the OEM case half seal is used in addtion to the anerobic sealer. Is this correct?

Thanks,
Lawrence
This is correct. The anareobic sealant is used as a redundant seal or backup to the normal case half seal in the even there is a scratch or imperfection in the joint sealing surface against the seal.