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Author Topic:   Broken Drive Train
Robert Carson
unregistered Total posts: 92
posted October 15, 2002 01:32 PM
Trying to figure out what happened: Limited Late Model, stock front clip actually full frame car, multi-leaf, solid engine mounts, engine-to-tranny mid-plate, tranny is T350, rear tranny brace (brace is constructed out of square tubing with 2 rubber “doughnuts” that the tranny rests on), stock drive shaft, 9” rear end. Been running this set-up for 1.5 seasons. Have cracked bell housing twice now. 1st time thought it was fluke (my mistake for assuming maybe uh?).

Last weekend was last points race of season. 1st time out since recently rebuilding tranny (new pump & planetary). Started on pole in heat race, race went green, made it to flag stand when loud “CRACK/POP” & I coasted to stop all the way around track to pit exit.

Results: bell housing cracked totally in 2 from driver to passenger side, drive shaft twisted in two, pinion gear snapped in two behind yoke, went from finishing season 6th in points to 7th.

Any ideas as to where to start looking?

Dirt Full Roller

Total posts: 69
posted October 15, 2002 03:03 PM
i would say that trany is too ridged it needs too have flex at the rear mounts . this will also slow the vibration fron engine . this would be where i look first if trany is solid.
good luck


Robert Carson
unregistered Total posts: 69
posted October 15, 2002 03:10 PM
"Skullhull" (Is that a "helmet"?), thought about rigidity factor. I've try to account for that:the rear of the tranny was set on & rubber doughnouts, with a bolt through the doughnouts eye, securing the brace to the tranny.

Appreciate the reply though & I'm still researching (1 more race this year)

Dirt Maniac

Total posts: 199
posted October 15, 2002 09:10 PM
When you bolt through the donut the way I think you did, you only have flex one direction. Stock rubber mount does not have steel to steel contact so it can flex in all directions. If you put a donut under the bolt head, then another under the mounting flange and one more between the mounting flange and the nut, all this with the mounting flange hole larger than the bolt you will have a truly non-rigid mount.
It think a stock mount might be easier.

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