M200 breakage
 

Well I finally got my stocker out after a year and a half of work, sweat and money. Booked in for the friday test day before the first bracket race of the year. Did some driving on the return roads and set the lash etc. Went down when the lanes opened and made my first pass ever in a class car. All was good, the launch felt excellent, pulled hard in first, second pulled hard, shifted into 3rd gear and BANG!! felt a thump on the floor after the BANG. Motor kept running, shut it off and pulled over to the side. Found the driveshaft in 2 pieces, twisted in the middle. The u-joints were both intact as well. The tranny case is busted all the way around and the trans pump and converter is busted up good. So my question is, the chicken or the egg scenario, did the trans case bust, push the trans backwards and bottom out the shaft and break it? Or did the shaft break, causing the destructive forces to break the trans case. I have read about the weak bell housing area of the 200, and the braces available, but I would have thought that a 305 would be easier on them, as I know guys run them behind big blocks. After I pulled everything apart, I think the trans case went first. Any thoughts on this? Also where can I get some of the bell housing braces? thanks in advance.

Dave

Re: M200 breakage
 

Thats why McClays come with a case brace.
I'm not sure if he will sell you one if you are not a trans customer.
How hard did it leave?

Re: M200 breakage
 

My car did the exact same thing . I believe it was caused by the stock driveshaft whipping. I installed a transmission brace and a larger diameter custom driveshaft and never had the problem again,

Re: M200 breakage
 

Bill,

It left good, felt good and looked good on video. It was 1.64, it was just ok.

Re: M200 breakage
 

What type of rear trans. mount do you have, should be stock rubber mount. Most guys with 200's (non Mclay) don't have a brace. There is a guy in B.C. Jim Mantle who does 200's I don't have his number, maybe somebody on the forum has . Sounds like there might be other issues. GSA 612

Re: M200 breakage
 

I spoke with Jim this weekend, he was at the track and he freshened that trans not long ago. He suggested the brace. He will be building me a new one.

The rear mount was one of the urethane energy suspension models, which came in the car, with the same trans, shaft rearend etc. It was working for years that way. thanks

Re: M200 breakage
 

I have a T200 without any bracing, but I do use a rubber trans mount. TurboAction 200 and never have had any problem. I was thinking you might have had a driveshaft problem, and it worked its way up stream. Mine isnt fast , by any means, but it goes 1.56-58, with a 1.54 best ever, at 50 over L weight.

Re: M200 breakage
 

We have never had a brace on a T 200 and have never cracked a bellhousing .
In fact , I always cut the ears off with a skillsaw and a carbide tip blade and de- burr the edges., Factory type engine mounts with a good, solid torque strap ,and a poly type mount.
I suspect your problem started with the driveshaft. Not sure why though.
On my Omega, (350 Buick stump puller), I shortened the original 2 and 3/4 ,thin wall shaft to accommodate the 12 bolt rear, and never had a problem with that either.

Re: M200 breakage
 

We use a stock rear mount on our Malibu M200 and the same trans has over 1000 runs without any breakage. We have a Mark Williams driveshaft with about 1 degree pinion angle. Smooth as anything.

Re: M200 breakage
 

Thinking about it more I would agree with what Bob and Mark both said. With the 60 foot you had the trans and drive shaft did not see a huge amount of torque. And I assume from what you said it did not shake or shudder on launch. It didn’t happen until the trans was in drive and starting to get up in RPM.
So probably something driveshaft related. The one thing I would check on the remnants of your transmission is the tail shaft bushing to make sure the yoke was not super sloppy in it. Could your drive shaft have been bent or dented? or overall length or yoke length a little short? Or touching drive shaft loop?
When Jim works on it you may want to also consider a roller bearing in the tail shaft.
Is that Peter Legg’s old car?
Are you going to have it back together for Bosie?