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Author Topic:   Breaking 3 speed tranys Help
Dirt Roller

Total posts: 19
posted August 30, 2004 02:19 PM  
Been breaking Saginaw 3 speed Trany ears and alum bell housings all season long. Really starting to drive me nuts. The ears break usually starting with the driver's side top ear. Then the passenger side top ear will break next. They don't break out by the bolt, they break at the base of the ear and crack into the case. Then fluid will start seeping out. Hopefully someone can help. Here's a rundown of the engine and trans setup:

83 Monte Metric chassis, 400 SBC engine with original factory crank, original factory balancer, and original factory flexplate. Ram triple-disk clutch with hydraulic throwout bearing. Using Saginaw 3 speed transmissions. Solid Moroso engine mounts and solid mount pads welded down.

Here's some of the things I've tried to remedy my problem:

I tried the solid engine mounts with the factory crossmember and a soft trany mount. Tried adding all types of roll cage bars to stiffen the chassis. The chassis is pretty stiff now. I tried mid-mounts and let the trany hang with no crossmember. Put the crossmember back in and tied a solid trany mount. The drive shaft has been balanced with new universal joints and the slip yoke sits 1" out of trany. Driveshaft only travels about 1/4". I've changed the 9" pinion yoke.

Currently, I'm running the old, heavy cast iron bellhousing. It seems to be able to hold up. But the trany ears keep breaking at the top and crack clear into the case. Whenever I try an aluminum bellhousing, it cracks right in front of the starter. I thought once I took out the crossmember and installed the mid mounts that would fix it, but it still breaks the same way. Anyone have a clue as to what might be causing all of this stress and breaking trany ears. I can put in a new trany and break it during the first heat.
Any info is greatly appreciated. Any other info needed I can provide.

Dirt Forum Champ
Total posts: 879
posted August 30, 2004 02:55 PM  
Sounds like an alignment problem.

maniac motors
Dirt Maniac

Total posts: 128
posted August 30, 2004 04:03 PM  
this may sound stupid but check the pilot bushig for wear. helped work on an act late model that boke 5 or 6 cases then we were changing clutch and the alignmet tool was way sloppy in bushing.changed the worn bushing and never broke another. as a note we did try all the things you have and had sorta given up and started stockpiling 3 speeds before we found the worn pilot bushing.(sometimes the simplest things will kick your a$$ for the longest time)

Dirt Freak

Total posts: 298
posted August 30, 2004 04:41 PM  
did you check the clearance between the throw out bearing and the clutch, If there's not enough the trans will not seat into the bellhousing flat.

Dirt Roller

Total posts: 19
posted August 30, 2004 10:57 PM  
I will check for alignment. Tranys go in and out fairly easy. The pilot bushing is a roller bushing, maybe I drove it in a little crooked or something. I usually set the clearance between the throw out bearing and the clutch at .100" like Quarter Master recommends. Thanks much for the info, I'll get to work.


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