Rear main Seal Install??

[HiPerf360]

Rear Main Seal Leaks like hoover Dam!!



Installed new rear main with the cummins supplied "install" tool. Tool Sucks, having difficulty getting the seal to go in straight. And when it does go in straight it slides right back out on its own. We were able to get the seal to stay down by running it all the way into the hole against the block. Either that was the problem or that fact that we molested the seal so much trying to get it to go in straight caused it to leak?? Can't seem to understand why the depth really matters as long as it's in straight.



Has anyone done this with success?? $50 a pop for the main seal really sucks!

 

[Don M]

Jonathon,



The replacement seal should have a pilot tool and driver with it.

The service manual asks you to put some mild liquid soap on the outside diameter of the seal.

Drive the seal into the housing until the driver bottoms or from 12,3,6 and 9 oclock positions to make it square to the crank flange.

Make sure the seal is level with both sides of the block oil pan rail.

Tighten the cover bolts to 80 inch pounds. The cover bolts may only be on the 4B engine or the 12 valves. I actually cant remember now. Gettin old and dumb.



Don~

 

[HiPerf360]

Hmmm... . didn't know about the soap trick... Oo.



Tighten cover bolts to 80 inch pounds?





Thanks for the reply Don

 

[jwilliams3]

Make sure to keep the seal housing level with the block pan rail surface.

Torque the bolts in a "G" pattern (start from the inside of the G).



If your seal was leaking before, check to make sure there is no

scratches or dings on the applicable surface at the end of the crankshaft.

 

[Bad340fish]

The 24V doesn't have any bolts to torque. The main seal has a rubber lining on the outside of it that is supposed to hold the seal in place. Its a *&^^%% stupid design in my opinion. When you get the seal in there nice and straight it slides right back out. Cummins scores pretty high on the dumbass meter for that design... sounds like the 12V trucks had a better setup

Clark

 

[Todd T]

so what caused his seal to leak.



I heard the clutch layed down on him, did it somehow cause the seal failure?

 

[Bad340fish]

Well it was leaking, so the job was while we are in there type deal that has turned into a real PITA... I think we figured it out that. If you take the transmision adaptor off the piece that the seal goes in can be removed. Last time I talked to him he has installed it on the bench and was getting ready to fire it up and see what was going on. Thank god you can start these trucks without the transmision on them

Clark

 

[HiPerf360]

Todd, the rear main started leaking a few days ago... the clutch problem had nothing to do with it. I was just going to change it while I had the transmission out.

 

[jwilliams3]

Bad340fish,

I must have miscommunicted something here.

The rear seal housing is secured with six tiny bolts.

To properly inspect the crankshaft for damage (which causes many rear seal leaks).

I would advise to remove the housing, prep the new seal using the soap and water. Then press the rubber seal into place with a flat object that applies equal pressure to the circumference of the rubber seal (bye the way make sure to get the seal seated to spec. ).



The rear seal housing has a gasket that seals it to the block. The rubber O ring that goes around the crankshaft

seals the crankshaft from leaking oil.



Good luck!



Bad340fish,

I have installed these parts on the 24 Valve ISB,

Actually this design works pretty well, unless a defect is present.

 

[Don M]

Those tiny little bolts that jwilliams is writting about is the ones I was saying should go down 80 inch pounds.

Since I have never had the 24V ISB engines down I thought maybe you were trying to say the 24V did not have the cover or housing any longer.

Wish I was more in-tune with stuff.

If the crank has groove worn in it, you can usually get it smoothed out with abrasives. If not, they make a wear sleeve to install over the crank to get it smoth again.



Don~

 

[Bad340fish]

Well... it seems if you take the transmision adaptor off you can get to the little tiny bolts lol glad it was Hiperf 360s $50 for that seal not mine LOL. . Jon will like that one.



The crank was fine, the truck only has 27K on it. But while we were fixing a broken clutch we figured we would avoid a trip to the dealer. Its on the road now

Clark

 

[HiPerf360]

LOL thanks Clark