Author Topic: LM7 Oil pan leak / Rear Cover / Rear Seal  (Read 1790 times)

Offline jfkelley

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LM7 Oil pan leak / Rear Cover / Rear Seal
« on: August 14, 2023, 07:01:38 PM »
:emotions122:
I have an 1977 K10 4X4 with an 2003 lm7 / 4l60e/NP241C ...I have a leak on the driver side oil pan the very last bolt ...The weird thing is it only leaks when I turn the truck off ..While its running no leak on the ground ..I changed the cam sensor thinking it was truly the culprit..SURPRISE!!! I was wrong :angry1: ...It doesn't leak anywhere else but from that very last bolt ...I have used mirrors ,dye and still cant locate the leak .. I was going to to drop the pan maybe put some silicone on the corner ...Honestly it could be coming from the barbell, rear cover or rear main seal when I changed all the gaskets i may have not aligned everything right .. I assume its coming from the top and running along the inside and dripping from that bolt for all I know .I can put my finger into the bottom of transmission cover and there is oil there as well ..I was hoping I could get some insight from some of you more experienced gentlemen...Thanks in advance ..

I do recall putting the black silicone on all four corners of the pan ..But then again i second guess myself If i used enough ...
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline VileZambonie

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Re: LM7 Oil pan leak / Rear Cover / Rear Seal
« Reply #1 on: August 14, 2023, 07:34:50 PM »
Very common for them to leak at the pressure point and run back toward the rear pan bolts. Tightening sequence, right stuff rtv, torque to spec.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10