I believe the rear main seal is leaking. I have oil on the clutch. This is a 87 V6 motor. My question is, how hard is it to replace the seal with the motor in the truck? I already have the transmission out and the flywheel is off of the motor.

 

I don't know; when the mechanic had my motor out to replace the freeze plugs I had them do the rear seal.

I'd consider pulling the motor anyway.

While out doing that, since you pull the oil pan ANYWAY, consider doing the pump and pickup. And while the pan's OFF, consider pulling the timing chain cover and doing the timing chain, adding the tensioner, and replacing the harmonic balancer. That all has to come off to do the rear seal; might as well go back in with new.

RwP

 

Hey Ralph. As always, thanks for your input!!

Without making this too long, let me explain what Im trying to do.

My clutch was slipping badly. It was too the point that the truck could not be safely driven.
That being said, my intentions has been to put a 5.9 carbed magnum engine in the truck. (in time)
My work, being somewhat seasonal, restricts how much time I can work with this truck.
I already have a NP231 transfer case and a NV3500 transmission for the conversion.
I planned to put the bigger transmission and transfer case in now, along with a 11in clutch and a 318 flywheel.
But, when I tore it down, I found the oily clutch.
I would like just to repair the rear seal for now. BTW motor only has 83000 act. miles on it.

I guess what I am trying to ask is:
Has anyone replaced the seal with the motor in the truck?
I have read on other sites of it being done, but its mainly been in A-bodies etc. The FSM talks about pulling the oil pan with the motor in the truck and talks about replacing the lower part of the seal.
I would assume, I would need to loosen the main caps to releive the pressure on the seal, and hopefully be able to roll another in.

Thanks for your input.

 

On my 95 4x4 it was a 2 piece and I was able to do it with the engine and transmission in the car. Just dropped the front axle and oil pan. Not sure if an 87 v6 is going to be different. Not a very difficult repair just time consuming. If it is a 2 piece offset the seams to the seems on the bearing cap and dap a little Permatex on the seal seems. Also a good time to replace your oil pump.

 

I also had all this stuff off too to replace the timing chain and add a tensioner and to powder coat the cover. ( Really good idea if are going to keep the engine) however I think the pan still comes off with this stuff still all in place but I'm not positive on that.

 

On my 90 3.9, I replaced the rear main seal. I had to drop the front axle to get the pan off. Removed the rear main cap to get to the seal. Mine had the old two piece rope seal. Pulling the upper half of the seal was a pain. I used a long sheet metal screw very carefully. Once I got it screwed into the seal, I used needle nose pliers to gently pull the seal. New seal went in east. At the time the transmission and flywheel were removed for a new clutch install.

 

check the back of teh intake manifold, valve covers and oil sending unit. all common leak points at the back of the engine, all more common leakers, and easier to do than a rear main.

 

Quote:

Originally Posted by cs1984

On my 95 4x4 it was a 2 piece and I was able to do it with the engine and transmission in the car. Just dropped the front axle and oil pan. Not sure if an 87 v6 is going to be different. Not a very difficult repair just time consuming. If it is a 2 piece offset the seams to the seems on the bearing cap and dap a little Permatex on the seal seems. Also a good time to replace your oil pump.

Thanks for your advise. Could you explain a little more how you offset the split? I linked the seal that I ordered for this engine and I dont see how it could be off set.

http://www.ebay.com/itm/Fel-Pro-BS40...RVygJD&vxp=mtr

 

Quote:

Originally Posted by Carl_S

On my 90 3.9, I replaced the rear main seal. I had to drop the front axle to get the pan off. Removed the rear main cap to get to the seal. Mine had the old two piece rope seal. Pulling the upper half of the seal was a pain. I used a long sheet metal screw very carefully. Once I got it screwed into the seal, I used needle nose pliers to gently pull the seal. New seal went in east. At the time the transmission and flywheel were removed for a new clutch install.

Forgot about this being a rope seal. Hopefully it will come out without having to remove the crankshaft.

 

Quote:

Originally Posted by volaredon

check the back of teh intake manifold, valve covers and oil sending unit. all common leak points at the back of the engine, all more common leakers, and easier to do than a rear main.

While I agree, all of those are common leak areas, in fact, I do have some leakage at the valve covers. But I dont believe any of these could get on the clutch.