Replacing CM871 crankshaft damper

[pearce trucking]

So I've removed the hood, CAC, condenser, and radiator. Tomorrow I'll be cleaning up the front gear cover.
My question is, what is the life of the front crankshaft seal. Should I replace it while I'm in there? I saw a special tool is used in the directions on quickserve. I don't want to replace it and find out I didn't install it right, thus creating a problem.
Thoughts?
I will be painting the new damper and replacing a couple squeaky pulleys.
Thanks.

[Waterloo]

You will need that seal tool to do it properly. I think, from my bad memory, run around $300 for that tool... If high miles on the truck, may as well replace it, especially with everything tore apart. If you are removing those front covers, they have those o-ring style gaskets. If you for some reason pull those covers, replace those o-ring style gaskets and save yourself a headache, been there, done that.

[pearce trucking]

I meant to do this sooner.
I changed the damper, pulley, and backing plate.

[pearce trucking]

The front motor mount bushings and lower gear cover seal

[pearce trucking]

Learned about the plastic spacer that is included in the crankshaft seal installation tool.

[pearce trucking]

And generally had a good time.:waaaht:
Plenty more to do next time.

[JMBT]

Pearce Trucking: looks good man!! I just did the same thing about 12K ago. Tell me about the plastic spacer? I ordered a knock off from a machinist on eBay. The tool worked great. It had metal spacers to control the depth of the seal when pressing the new one in. But no plastic spacer?? Maybe different between the 2250 and 871?

[pearce trucking]

I bought the tool from Cummins. I believe it is designed for more than one engine. Possibly 570 or 870, not sure.
The side pic of the seal that I posted is of the seal after installation with the metal tool. The plastic spacer looked like a piece of packaging to me. Well I overlooked the instruction regarding the spacer as I was using quickserve. There was also an instruction sheet in the tool package that specifically mentioned the spacer.
So without the spacer, the outer ring of the seal went to correct depth against the lower gear cover. However, the inner ring of the seal was left about 8mm shallower, hence the gap in the pic.
I actually bought a second seal to reinstall with the spacer, even though I was pretty certain no damage was done to the first one. I figured $88 was cheaper than tearing everything down again on the off chance it leaked. Using the spacer with the metal tool the second time set the inner ring to the correct depth on the crank, and there was no gap between the rubber parts of the inner and outer seals the second try. I did this in October, and have put 25k on the odometer with no leaks.
I do think I need to retorque the engine mount bushings however.
Incidentally, the screws included with the seal installation tool that are used for removal of the old seal were the wrong size, and I went to Home Depot to buy the correct size.
All in all I'm happy with the results, as the vibration went away after I changed the mount bushings and vibration damper. (Imagine that) Also I used ATRO polyurethane bushings.
However, if I'm going to spend $300 on a tool, it would be nice if quickserve had the correct instructions, and also if the correct hardware was included. Go figure.

[JMBT]

Gotcha! Yes it must be different for the 2250. I had no plastic spacer or mention of one on quickserve. But thanks for the info, very interesting.