[texaspro]

Quick question do i have to pull the motor on my 4 speed judge to change the seal ?

[tom s]

Pretty much,not impossible but damn near.Tom

[rexs73gto]

Pull the engine & make sure it's right. Putting in a rear main seal is a pain in the A$$ when it's out of the car. Which type of rear seal are you going to put in??? The rope seal will proberly leak & the 2 piece seal has to be out to position it correctly. The new 1 piece seal takes 2 people to install it because the way it goes in. So you have your choices.

[68ragtop]

If your changing it to stop a leak, its probably going to leak again, especially if its one of todays replacement rope seals.

I have installed several BOP rear seals with great success. However, they are not very forgiving & have to be installed correctly. Some blocks are not line bored dead center of the seals recessed area & you have to use shims to get the correct lip pressure on the crank. Then they have to be trimmed after that on the ends. Fantastic seals when put in correctly & will not leak, but its a complete crapshoot if the block is not upside own on an engine stand with the crank out to measure everything.

Here's a picture form the the last one I did. You can see the brass shims I had to add to get the right position of the seal. I installed it with somewhere around .010" of pressure against the crank at the lip of the seal. It can be measured with a straight edge right off the journal. On this engine I had zero seal pressure on my mock up. Then I installed the shims, had to add them to get it to fit correctly. worked beautify.

The only leaks that can get past are from the grooves in the crank that were originally designed to pull oil in against the rope seal. I have the machine shop polish that area to help minimize leaks there.

[ANDYA]

If you have a GM crank then I would use the Best Gasket graphite rope seal. There lots of folks using that seal without any issues. I installed one in my 428 3yrs ago and so far not one drop of oil has leaked out. The key to success is to have the engine out and upside down like others have said. Follow the instructions carefully and take your time.

[tom s]

Just use the new 1 Pc BOP seal,have 2 running now.Tom

[ponyakr]

As tom s said, it's not impossible. I did it in my '69 RA3. Had to make a punch, the basic shape of the groove, tap the ends of the old seal up into the groove about 3/4", work some pieces of new seal into the groove, cut & trim even with the block, then install the other half of the seal normally into the cap. You can find the exact instructions I used, in the '69 Pontiac service manual, section 6, pages 62 & 63.

Hey, it worked for me in '73. Raced it for 2 seasons--no leaks.

But, if I needed a seal today, I'd pull the engine and use the one piece BOP.

[texaspro]

I was hoping to avoid pulling the engine. I wanted to wait to replace some other stuff (clutch etc) so for the time being I'll put a pan under it to catch the drips and start looking for drive train parts. Thanks guys for the insight!

[rexs73gto]

There's a number of items in the parts store that will slow down & some times even stop your rear main leak , look for it & I think that will give you the time you need.