rear main seal

[Troutdog]

I got a little free time on my hands now and I think I'm ready to tackle this project. Maybe I'm just getting tired of looking at my usual parking spots. I just want to know whats involved in changing the rear main seal. Is it something I should let a pro do or can I do it myself. I'm pretty confident I can do it, I just would like to know some details. Thanks

 

[Steve Graham]

The hardest part of changeing the rear main seal is getting the transmission out of the way.....

Anyway Cummins has a seal kit that has the seal and the installation tool along with detailed instructions on doing the job. You will need a hand drill, a drill for a no. 8 screw and two no 8 screws that are not supplied and if you have a slide hammer it makes it that much easier. Just drill the holes into the seal, install the screws, pull the old seal out and use the supplied tool to install the new seal. And then your ready to install the transmission. I just did a real main seal on the 4BT in my scout and it was a easy chore.



STeve

 

[bkokotovic]

I'm real interested in this. I've had a main seal leak since I got the truck. Dealer said $600 for the job. Don't think so.

 

[Whitmore]

Steve you said the hardest part is getting the trans out of the way , and I couldnt agree more, do yourself a favor and buy a trans adaptor for your floor jack, they are the cats meow, got mine from Northern Hydrolics... ... ... ... ... Kevin

 

[KEENO]

Hey Troutdog & gang!



It's a fairly straight forward job as mentioned by others... . Just a few heavy parts.



The only thing I can add is to follow the Cummins instructions to a "T". The seal must installed "DRY" to properly mate to the crank because it's teflon coated.



I took my job one step further than the 'sheet metal screw' proceedure and actually removed the aluminum "rear mail seal carrier" from the engine and pressed the old seal out & the new seal in using a press w/ well distributed pressure. I felt better about removing a few more bolts and not using a drill near the 'main journal'. I know my luck... If I'm going to mess up, it's going to be on the most expensive - hardest to access part!



KEENO

 

[Lil' Dog]

For my money I am going to install the sleave kit as well. It is the same price for the seal kit with the sleave as without, about $140 Cdn from Cummins. That way if the crank is scored a little, you won't be replacing the seal again next year... MHO



J-eh

 

[Harlan]

If you install the rear main seal with the sleave you will need the instalation tool. It all goes in as a unit. Just did mine last week end and no truble. Read the instructions and fallow to the letter. I barowed the tool from case as there 4B is the same moter but 2 less pistons. Hope this helps.

Harlan

 

[Troutdog]

Since you put it that way

All I need now is to get in touch with a Cummins dealer, or would a dodge dealer have this kit?

 

[KEENO]

One other thought!



If you part the NP205 T-case from the Transmission you might want to consider replacing the input seal for $5. 00 from NAPA or other on the T-box. If not... Let it ride.



My truck's rear main was done @ 180,000 approx and the crank journal was perfect. So I just used the normal kit (w/o Sleeve) and had the Cummins shop press the seal into the carrier while I was there waiting. It was their suggestion to remove the "aluminum rear main carrier plate" VS the 'sheet metal screw' method for the extra few moments it takes. A new gasket is required w/ this method though (cheap).



The girl's truck now needs a rear main also ... . So I'll be back under there before I know it.



KEENO

 

[KEENO]

I used my local Cummins shop for the seal/kit and it ran $80. 00-$85. 00 USD complete (seal/installation guide/directions).



They even did the press work for free after asking nicely... Didn't want to booger up a $80. 00 seal on my own!



KEENO