THM400 grinding at medium throttle
Thread Starter
Race Director
Joined: Oct 2000
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THM400 grinding at medium throttle
My friend has a ZZ502 in his truck attached to a built TH400.
Under light throttle, or heavy throttle, it is fine, but at medium throttle, right before the torque converter grabs(2800 stall) it grinds pretty badly.
The transmission is still under warrantee, but the tranny guy is stumped as to what is causing it, so he doesn't know how to fix it. The trans shifts just fine and stays a reasonable temperature, it just grinds...
Thanks for any suggestions.
Under light throttle, or heavy throttle, it is fine, but at medium throttle, right before the torque converter grabs(2800 stall) it grinds pretty badly.
The transmission is still under warrantee, but the tranny guy is stumped as to what is causing it, so he doesn't know how to fix it. The trans shifts just fine and stays a reasonable temperature, it just grinds...
Thanks for any suggestions.
Melting Slicks
Joined: Apr 2000
Posts: 3,341
Likes: 6
Re: THM400 grinding at medium throttle (NoWorries)
The FIRST thing I'd do -
Haul the pan off and get it out where you can see into it easily. Stick your fingers into the oil and swish them around. This will stir up anything that has settled onto the bottom of the pan.
No stuff in oil = good.
Metal flakes in the oil = very, very bad.
The SECOND thing I'd do -
Take out the filter. Once again, you are looking for metallic contamination.
If you find metal flakes, chunks, etc --> take the pan + filter (as is) to the tranny guy and show him what you found. The ball is now in his court.
Haul the pan off and get it out where you can see into it easily. Stick your fingers into the oil and swish them around. This will stir up anything that has settled onto the bottom of the pan.
No stuff in oil = good.
Metal flakes in the oil = very, very bad.
The SECOND thing I'd do -
Take out the filter. Once again, you are looking for metallic contamination.
If you find metal flakes, chunks, etc --> take the pan + filter (as is) to the tranny guy and show him what you found. The ball is now in his court.
Thread Starter
Race Director
Joined: Oct 2000
Posts: 16,477
Likes: 1
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Re: THM400 grinding at medium throttle (45ACP)
Thanks for the reply. The truck is at the transmission shop now and he is going to look at it, but it doesn't sound like he knows whats happening.
Its a known builder too, which is weird, he's built 400's to run behind engines with twice the power my buddies truck is making.
Its a known builder too, which is weird, he's built 400's to run behind engines with twice the power my buddies truck is making.
