help! locked up lb7 or is it transmission??

justin19

New member
Jul 1, 2024
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booger019.
i have a 02 that has ran fine its whole life at 310,xxx i finally decided to do headgaskets. i let the shop do the job(sinister gasket and arp2000s kit) and got 1200 miles out of it and it completely shut off and locked up on my wife. Thankfully she was only doing 20mph and was able to safely pull over. didnt happen under heavy acceleration, no smoke from exhaust, no noise, no nothing just shut off. I went to where she was on the side of the road and sure enough it acted like bad starter or dead batteries, checked belt, checked voltage all good. i put key in on position and crawled underneath to jump starter and i could hear the bendix come out but no crank. towed it home and put a breaker bar on the crank bolt and all i did was tighten the crank bolt (didnt move either direction)Any ideas? ive read that its possible for the pump in the allison to fail and lock up input shaft but at this point thats wishful thinking.

ps no metal in oil or filter
 

2004LB7

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Dec 15, 2010
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Another member had something similar happen. Was the transmission. Had to cut the converter with a plasma cutter to get it off

Check in the little inspection plate where you can see the converter. Bump the starter over and see if you get any movement at all. If you can get the engine to rotate then maybe you can get all the converter bolts out and see if it frees it up

 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
It is a bit of an involved process, but you should be able to tilt the back of the engine & transmission down, then slide the trans off the torque converter. Then you will know for sure which one is locked up without doing any destructive disassembly.
 
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justin19

New member
Jul 1, 2024
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booger019.
Another member had something similar happen. Was the transmission. Had to cut the converter with a plasma cutter to get it off

Check in the little inspection plate where you can see the converter. Bump the starter over and see if you get any movement at all. If you can get the engine to rotate then maybe you can get all the converter bolts out and see if it frees it up

I haven't had a chance to pull it yet but this is where I will start. Its 2wd won't take much
 

2004LB7

Well-known member
Dec 15, 2010
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idk it would have to fill the cylinders awfully fast to lock up and shut off, it didnt smoke at all
If it was hydro locked it should free up in a few minutes after it leaks past the rings. If it's just as stuck now as before then it's not hydro locked. And I'd start with doing as Dave suggested