Stock class transmission case breakage
 

Recently, I have received a large amount of concern over automatic transmission case breakage and safety concerns. I am interested in finding out how much a problem this is in the stock class. Your comments are greatly appreciated.

Tracy Winters

Re: Stock class transmission case breakage
 

Not a problem for us. However, we already approached NHRA, they are unwilling to accept aftermarket cases in Stock Eliminator. Well, at least for the automatic transmission cars.

Re: Stock class transmission case breakage
 

The only time I have encountered trans case breakage was due to chassis flex. With a properly installed roll cage and proper bracing there should not be any case breakage. Solid motor mounts, rubber trans mount and no chassis flex should eliminated breadage.

Re: Stock class transmission case breakage
 

I recently had this problem with the TH350 in my stocker. We never could figure out why the case broke like it did, but I called Wesley (Div. 4 tech man) and was told that OEM case only. It seems as though NHRA would rather leave it alone or move Stock into Superstock rather than allowing more superceded parts like trans cases.

Re: Stock class transmission case breakage
 

I've broken just one case in 30 years of racing and that was related to a U-joint failure....knock on wood!

Re: Stock class transmission case breakage
 

I agree. I think using the wrong type of mount would cause our cars the most trouble. On a related note, do the JW bellhousings with the 30.1 flex plate sheild rating require indexing?

Re: Stock class transmission case breakage
 

So NOW the NHRA does not want to allow better parts. It like closing the barn door after the cows have all left the farm !

Re: Stock class transmission case breakage
 

The bellhousing is SFI certified 30.1 for the flexplate shield and it fits onto the stock transmission case. You do not have to use an aftermarket transmission case. If I am correct the flexplate shield is required for vehicles running 10.90 or faster. I am not sure that I understand the question regarding the indexing? Let me know how I can assist you further.

Re: Stock class transmission case breakage
 

Tracy- PM Sent

Re: Stock class transmission case breakage
 

We index them. Have seen them off as far as .035". I'd rather be safe than sorry. $0.02
Larry

Re: Stock class transmission case breakage
 

We were not looking to solve a breakage issue. Rather, we were looking at improving a safety problem. If you've ever tried to get a transmission shield on a 3 speed in one of the upper class cars, as well as a flexplate shield, you'll know what I mean. They require us to use such equipment (I'm not opposed to safety at all) but then they force us to try to cram it into a stock transmission tunnel. Actually, solving any breakage issues was a side benefit.

Re: Stock class transmission case breakage
 

This. It would be much easier to have a certified case

Re: Stock class transmission case breakage
 

The racers that I have spoken to are interested in using the "Ultra-Bell" that bolts to the stock transmission case to help eliminate breakage and for safety concerns. The transmission case is not a concern at this time. My purpose of participating in the forum is determine if there is a problem with case breakage or a concern for safety. Thank you for input.

Re: Stock class transmission case breakage
 

Our only breakage issue was a TH350, and I'm sure that was a driveshaft problem. Had we had a bolt on bellhousing, I'm sure the case would have broken at the next weak point, behind the pump. That would have put fluid on the track.

The safety issue is a good one to pursue, however, if you need a flexplate shield, you also need a transmission shield.

Your Ultra-Bell helps with the flex plate shield, and that's great, but that leaves the racer with a blanket as the only option for the rest of the transmission, since you cannot cut or modify the form fitting carbon fiber style shield, which, for many of us, is the only thing besides a blanket that fits in the tunnel.

Re: Stock class transmission case breakage
 

I understand your position and thanks for all your input.

Re: Stock class transmission case breakage
 

I have seen several th200 break the cases, somebody even sells a girdle to prevent it.

Re: Stock class transmission case breakage
 

I have broken several TH200 cases. In my situation, I fabricated a brace along the passenger side of the case connecting the two factory "ears" made of 1/2" thick aluminum about 1" to 1 1/2" wide. In addition, I bought a Turbo Action cast aluminum deep pan to help stiffen the case. The third item was to install a torque strap on the front left cylinder head to the frame. After those changes, there has been no further breakage. If you do these changes, be prepared to notch the crossmember to clear the pan on a Camaro or Nova. Also, the transmission cooling lines need to be figured out before installation of the transmission because the brace (at least the one I made) makes it almost impossible to install the upper line afterwards in the car. We used a 45 degree angled top end on a hydraulic hose to solve this problem for our cooler lines. Hope this helps.......

Grant Eldridge
E/SA 6650

Re: Stock class transmission case breakage
 

If the girdle works than that is great. We do have a 200 metric bellhousing to a GM engine that is available. It is available through a distributor who paid the tooling and etc... to make the product for their specific market. It may be of interest to those racers with a 200 metric transmission. Thanks for your input.

Re: Stock class transmission case breakage
 

I was in Norwalk this past weekend at the NHRA event. For those racers who are interested interested in safety and have case breakage issues I suggest that you voice your opinion to Bruce Bachedlder of NHRA. They are willing to listen and look into the matter further. Your safety is important to the manufacturers and the sanctioning bodies. If you need contact information please e-mail me at tracyw@racewithjw.com.

Thanks

Re: Stock class transmission case breakage
 

What case is used on the Cobra Jets and Challenger 2-speeds?

Re: Stock class transmission case breakage
 

I am not sure, but I will check into it and get back with you.

Re: Stock class transmission case breakage
 

See the information posted below and whom you may contact to voice your concerns to NHRA regarding this class and safety.