Just like about everyone else with a 5.9, I had a leaking rear seal. Always leaving my mark wherever I parked and rust proofing my tow car.

So I pulled the transmission, removed the flywheel and there was the culprit.

According to the documentation I needed to drill and use a sheet metal screw with a dent puller hammer to remove the old seal. What really happened is my old seal just about fell out. It was so bad I am not sure it was doing any good at all.

Anyway installed the new seal, reinstalled the flywheel and let the engine run for over an hour. No oil has appeared. Will remove the flywheel tomorrow and double check. If it turns out that the new one is leaking I will write it off as a learning experience and do it again.

Total time to R&R should be less than 8 hours or in my case 8 days. Social stuff keeps getting in the way.

I did take one picture after the seal was removed. Will take another with the seal installed. They will be added later.

If anyone needs more info speak up. Easy job. Just lots of bolts and nuts.

It appears the 8.3C engine uses the same seal so all this applies to that engine also.

Wow, sorry to hear that. Do you think hot rodding
the engine might have been a contributing factor?
I had a 5.9 in a '91 Dodge pickup at 175hp, at a
quarter million miles it ran like new and had never used a drop of oil. My '95 8.3C in a Winnebago stock at 300hp has also never used a drop of oil. Your experience is diametrically opposed to mine.

Hot rodding the engine had nothing to do with seal leak. This is a very common problem with the Cummins B engine, according to the shop foreman where I bought the seal. It appears the latest version will hold up.

Was talking to a neighbor down here. He had to replace the seal in his combine engine (5.9B).

Also check out the Dodge diesel forums. Lots of folks have or are doing the same thing.

The drain hole in the bottom of the housing is for wet clutch application. Cummins just uses the same bell housing for everything. Not sure if the Dodge version is the same or not.

Well Gary, you may shame me into doing this later. I have to go on the stupid cruise tomorrow so I can't start it until I get back.

I am NOT looking forward to this job, in my case with MD3060, it weighs 200 lbs more than yours (dry weight) bigger fixed hoses that will have to come off, they will not allow the trans to be moved much further back. Maybe I could swing it around a bit to get access but it is a HUGE, HEAVY unit.

I will replace the driveshaft "U" joints while at it. Probably clean/inspect/replace the "E" brake unit also.

Ed,
I'm surprised you're not replacing the seal with an 8.3 wrapped around it

I had considered it but the 8.3 is WAY to heavy for the 30' pusher. my preliminary research suggests that the 8.3 is about 500 lbs MORE than the 5.9. It is also 4 inches longer.

Engine change time for me will be the 6.7 crate engine that is tuned from Cummins at 800 lb/ft torque. Should do the job.

Just turned 165K miles so I think in 2 years I will be at or near 200K good time to refresh the engine and trans.