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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: chevyh20 on December 03, 2010, 09:14:55 pm

Title: rear main seal replacement steps
Post by: chevyh20 on December 03, 2010, 09:14:55 pm
Hi Guys ,
I am changing the transmission on my1989 blazer while i have everything apart i thought i would replace the rear main seal also. can some one give me a step by step procedure for me to follow? thanks a lot for the help in advance. i am putting in the replacement tranny tomorrow and hope to do the rear main first.
Title: Re: rear main seal replacement steps
Post by: VileZambonie on December 03, 2010, 10:08:21 pm
Are you planning on changing the housing seal too? If not just carefully work the seal out without scoring the crank. Lube the new seal and on the outside you can put a small coating of liquid teflon. Start the seal onto crank carefully without damaging the lip. Then rotate the crank a little to get it to slide on over the crank. Once you're sure it's OK drive it into the housing eaither using a seal driver or a flat punch working it in til it's flush.
Title: Re: rear main seal replacement steps
Post by: Psycho71 on December 04, 2010, 12:16:05 am
I've always been told to run the 2pc rear mains with the seams about 1/3 offset from the seams on the main cap. Keeping them staggered supposedly helps prevent leaking (so I've been told). I do it, and don't think I can remember one leaking on me. Do you see any merit to doing it this way? Just curious?

Respectfully
Title: Re: rear main seal replacement steps
Post by: Irish_Alley on December 04, 2010, 12:30:43 am
ive heard that two i think it was on horse power
Title: Re: rear main seal replacement steps
Post by: VileZambonie on December 04, 2010, 08:46:14 am
The 89 would be a one piece rear main seal but yes stagger the gaps from the caps
Title: Re: rear main seal replacement steps
Post by: chevyh20 on December 04, 2010, 09:25:57 am
yes ,
it is a one piece seal. should i also change the gasket under the retainer. or is changing the main seal enough . by the way the seal is not leaking , just thought it would be a good oportunity for pre-emptive maintainance
Title: Re: rear main seal replacement steps
Post by: Psycho71 on December 04, 2010, 12:21:03 pm
Ahh, I guess I overlooked the '89 part in the OP. Doh!
Title: Re: rear main seal replacement steps
Post by: chevyh20 on December 09, 2010, 09:47:35 pm
ok,
this was really easy. pryed out old seal and pressed in new one. i used the old seal to tap in the new one. it worked good. thanks for the advice.
Jeff