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Old 09-17-2010, 05:22 PM
Billybob Billybob is offline
Join Date: Nov 2001
Location: Cape Cod Massachusetts
Posts: 1,427
Originally Posted by Army View Post

I've not seen this information on this forum before (disclaimer:- but that doesn't necessarily mean it isn't here) so I thought I'd add the thoughts of this engine builder I've pumping for information.

This is regarding the rear crankshaft seal NOT THE FRONT ONE but nevertheless may be of interest to some...

According to this guy if the REAR crankshaft seal is incorrectly fitted a lot of heat can get build up that can speed the failure of the main bearing closest to the REAR crankshaft seal.

For rebuilding my engine (that I'm now about to embark upon) I have been told to carry out the following procedure for fitting a rear crankshaft seal.

1) Before you start with the seal - fit the crankshaft and tighten the mounts (make 'em tight but don't go as far as torquing them) and make sure that the crankshaft spins freely. Remove crankshaft and remember how freely it span.

2) Once you are ready to fit the seal - lubricate and place a new seal in block and do the "usual" trick with a hammer handle to gently push the seal into position

3) Cut the ends slightly proud and then with a punch tap these ends flush

4) Now refit the crankshaft - torque as specified - and make sure that that it spins as freely as before.

5) Repeat the necessary steps above to make sure that the rear crankshaft seal on the upper oil pan isn't restrictive.

It seems like a good plan to me. Anyone got any comments?
So the plan is to fit things together without torquing to spec, observe and "remember" something, then install something that inparts friction, torque things to spec, then observe and compare to a "remembered" prior observation of something under different circumstances? And if not reconciled, repeating that procedure until you've convinced yourself things are correct!?

I suspect the heating bearing damage to be complete BS, and I'd follow the FSM rather than someone who came up with that. MB engineers are not perfect but you've got to give them some credit where credit is due and assume that they at bthe very least have considered the obvious when designing these systems and maintaining them.
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