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Old 09-11-2019, 05:53 PM
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How to inspect 4L80e pump and TC for damage?

Because I have the brain of a hamster, I installed my rebuilt 4L80e and triple clutch billet-backed TC along with a pilot bushing that came with my engine adapter kit that was labeled as "mandatory."

Long-story-short I got all the bellhousing bolts hand-tight, then heard "POP....... POP". The flexplate and TC were unable to turn. I disassembled everything and found that the pilot bushing had separated into two halves,... I attributed the popping sound this this. However, it could have been the bushing AND the trans pump I suppose.

I'm not extremely experienced with the 4L80e (obviously), can anyone tell me what to look for to determine if my pump is toast? If I need to remove the pump to be able to see the damage, is it as simple as unbolting it, pulling it out, unbolting the two halves, inspecting, reassembly and torquing the pump back down? Or is there some precision that goes into reinstalling the pump like setting depth?

Also, would the amateur move described above also potentially damage the torque converter? Such as if the trans shaft got pushed in too deep? How would I confirm that it is fine?

Thank you in advance!

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Old 09-11-2019, 06:23 PM
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Yes you could have damged the converter. Look at it for damage, scrapes, dent, dings on the hub...

You say the pilot bushing cracked in half? On the converter or what part are you talking about?

Checking the pump: an experienced person could look inside to see if the inner pump gear is broke or damage to the bushing.

If you remove the pump and disassemble: Yes.... this is a precision process. It is not a simple remove , unbolt the pump halves , bolt back together and replace deal.
Dont worry how old you are... it is the mileage on your body that adds up.
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Old 09-11-2019, 06:30 PM
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Thanks for the quick and helpful reply!

I had to use an adapter plate between the engine and trans. The plate came with a pilot bushing to extend the rear hole of the crankshaft a distance equal to the thickness of the plate. However it ended up just getting in the way and caused the TC to not be able to slip deep enough into the crank. That bushing came apart under the pressure, leaving half inside the crank and half as a ring around the TC.
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