The factory oil seal leaked at 155k km/6200 engine hours, the replacement went at 254k km/10200 hours. I expect I will be replacing the seal again in the near future.

Has anyone replaced the seal without taking off the gear cover? Cummins wants the gear cover removed and the seal driven in from the inside of the cover. The Haynes manual for the Ram trucks shows the seal being replaced without taking the cover off. I tried once without taking the cover off and I just could not drive the seal in. I ended up damaging the seal and had to go buy a new one.

Last time I used The Right Stuff gasket maker on the cover. It is really sticky stuff, so I expect some difficulty taking the cover off next time and cleaning the gasket residue off. Cummins does not have a gasket for the front cover, are there any aftermarket vendors with a gasket?

 

https://www.dieseltruckresource.com/...t-t126282.html

 

Strange, in the post linked to, the author mentions Cummins FSM showing the seal installed with the cover in place. I have the Cummins FSM, Troubleshooting and Repair Manual for ISB and QSB5.9 Engines, Cummins publication number 3666193-01 and it asks you to remove the cover to install the crank seal. I took a photo of a relevant page
http://i299.photobucket.com/albums/m...1/100_0521.jpg

Next time I change the seal, I will try pressing it in with a 2x4, without removing the cover, as shown in that post.

 

ive only done them by taking the cover off and resealing the cover with RTV silicone, I don't believe a gasket is available any more and cummins recommends grey RTV

 

If I recall correctly the gasket for the 12v fits but mine was done without removing the cover and once with the cover off using grey rtv