Need help with Cat 3406C rear main seal

Carefully cut through it with a small chisel then pry it off. Then go and borrow an installer tool from a shop to install the new seal assy.

 

I'm with Bender on this one. The ring on the Crank is only a runner. A special tool is needed for seal replacement. The new seal is called a seal group. DON'T replace only the outer of the seal IT WILL LEAK. GUARANTEED.

 

If the shop has the installer then they most likely have the deliver tool it is a still ring that fits inside the flywheel housing then you insert a special tool with a cutting side that looks kinda like a square easy out and rotate the remover tool and it cuts a line in the wearsleeve similar to a hammer and chisel do that a couple diffrent places then the sleeve comes right off

 

Bender is correct on the seal installation .
The old wear sleeve comes of with a special tool a steel ring that protects the housing and a triangular tool you turn to stress the wear ring. It makes the wear sleeve larger untill you can slide it off. Where you bought the seal should lend you the removal tool.
Do not try and cut it off with a chisel you will damage the crank and then the new sleeve will not go on properly and the seal will leak.

 

all these tools that is being talked about is very hard to come by. if you do use a chisel and dent or mark the crank, i would use some kind of liguid steel in the mark then fine sand paper then polishing cloth. take off the excess liquid steel with out taking any off the crank. i live in between st louis and memphis could not find a installer tool any where close. had the local black smith make me one. its odd lookiing but works. if you are near you are welcome to use it. if you know or if you are a decent tinker they are not that hard to make.

 

i have a hard time finding truck shops with mechanics old enought to know how to work on a mechanical cat. i will useualy try to get a heavy equipt. place to take it in for engine work. if the dealer cant plug their lap top in to it they are lost.