help! TH 400 problem
help! TH 400 problem I had my ATI TH400 rebuilt by ATI just before I ran the Pinks race and during the third pass I lost second gear. I was hot lapping the car so it was hot. I pulled the trans and the only issue I saw was that the second gear sprag was flipped so I put in a new sprag and went to the track and first pass I have second. next pass it goes again pulled it tonight and the second gear sprag has flipped again! What could be causing this I'm not making enough power to destroy a 400 every time at the track help I have another race this weekend and need to figure this out fast. Thanks
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hey Sprag inner or outter race to big on the outer or to small on the inner assumeing your useing good quality 34 unit sprags and not this chineese imported, junk.alot of that on the market..Hope this helps Dave
TECH Regular
Joined: Feb 2004
Posts: 439
Likes: 1
From: burbank ca
when the sprag rolls it usuallly ruins the inner race, so it is best to get a new one. if you have a way to measure the id of the outer race and the od of the inner race use the largest inner and the smallest outer. by the way change both races. oh, you CANNOT swap inner races. they are ground after they are pressed on.
I'm using the best sprags ATI sells but thats all I replaced. The rest looked ok but I didn't measure anything just threw the new one in damn! This is gonna get expensive! Any other thoughts what parts would you guys recomend I replace and where should I get them? Thanks!
TECH Regular
Joined: Feb 2004
Posts: 439
Likes: 1
From: burbank ca
races l have production inner races before they are ground, and have them ground to the max allowed. l don't know what else to do. l feel for you but some folks grind the roller races to fit the sprag and that aint good
