Engine/Transmission (1998.5 - 2002) How many people change rear main seal on motor when changing clutch

[TPlasek]

How many people changed the rear main seal on the motor when they change the clutch. I have my trany down and have the flywheel off to get resurfaced. The rear main is right there, but it hasn't leaked a drop. I am a little nervous to perform the fix it till it breaks routine.



I have 92k... How many miles do the rear main seals go before they start to leak???



Anyone have the part number(2000 3500 4x4)???

 

[JLinder]

Just put a clutch, let seal alone

I guess I'm sort of lazy, but I didn't change my seal. Couse, I've only got 30k on my motor. I think in your case I wouldn't worry about it. Can't saw for sure on our motorsl, but think of the bigger inline 6 diesels. They have similar overhaul intervals and don't have rear main seal problems.



I'm not an expert, but just my thoughts.

 

[Bigramguy]

If it ain't broke,don't fix it

Some people may disagree,but I'd leave it alone. The truck isn't that old or high mileage,so it will be fine. There are too many things that can go wrong (seal damage,wrong seal,seal lip folded over,etc etc) when putting in the new seal,and you sometimes don't know till it's all back together and running.

 

[BWilson]

I agree with Bigramguy 100%. My truck is at 392,000 and still doesn't leak out of the main seal

 

[bighammer]

I didn't change mine. I figured I had enough disassembled, didn't need to make the job bigger.

 

[A Johnson]

The new rear seals are really good, it was the older trucks that had problems and the problem was with the seal construction and loctite on the outer perimeter failing, causing leaks between the seal and the housing and the steel laminations of the seal carrier. I can't remeber what year this was changed but if you look at an old seal and the new seal, the new seal has a rubber coating on the carrier. So I say leave it be. More chance to cause a problem then prevent anything.

A Johnson

 

[WadePatton]

I've done it twice on the gas-burner.



But I agree with the other folks here. I'm going to leave the Cummins plug in when I do the clutch at 60k or so. Maybe after 250k.

 

[TPlasek]

Ok, you talked me into it, I'll leave it in there. Thanks for the info on how long the seal should last. That was the info I was looking for.

The seal hasn't oozed even a drop, and I would hate for something to go wrong when I put the new one in. I am aware of how many things can go wrong and how much work would be involved to change it again.



Thanks for all the info...

Tim Plasek

Houston, Tx

 

[fj40charles]

Hey Tim,



What kind of clutch are you putting in? Will you be ready for additional power?



BTW, I didn't change my rear main seal because I didn't want to touch it and screw it up.



Did you fix the NV4500?



Charles

 

[TPlasek]

My transmission had a bearing go out. All the rollers fell out on one of the two main roller bearings on the bottom cluster gear. It looks like a lubrication problem. The lube in the transmission looked very bad at 92k. It had lots of synchronizer material mixed in with the oil as well as the fluid looked dark brown and smelled burnt. The synchro material had already started to pack in the bottoms of the oil journals and in the bearing cages for the needle bearings that the gears ride on. Lots of "MUCK" throughout the transmission at 92k. I put all new synchros in as well as all bearings and seals. I think I will be changing the fluid on a regular basis from now on.



As far as clutch, I just put in the $275 South Bend. Peter talked me out of the more expensive Con OFE FOR MY NEEDS. The one I got is stock pressure plate, stock clutch disk hub, with "their" special disk material on the clutch disk. It looks similar to my old disk but the new one has more surface area contacting the flywheel and clutch.