Author Topic: Tranny supports?  (Read 983 times)


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Tranny supports?
« on: January 21, 2024, 10:55:59 AM »
New build, trying to figure everything out.  Got a 200" frame, w/alky 555 BBC and 2 speed glide.  My question is do most people use a conventional support for the trans running across the frame rails, or no support at all?  I've talked to some guys who said they run a support bar inline with the trans, rearend and motor to prevent frame flexing.  The trans is set up to be bullet proof and is extremely heavy and seems too much weight to be hanging off the motor plate without a cross support of some sort.  Thanks in advance for the help.


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Re: Tranny supports?
« Reply #1 on: January 21, 2024, 06:40:17 PM »
I use a rear crossmember mount>
It is not a good idea to bolt it rigidly to the crossmember. There will always be some minute degree of chassis twist between the rear block plate and the crossmember. That will strain the trans case and internals.
Rather, I use a 1/2" thick hard rubber block between the tailshaft pad and the crossmember pad and do not torque the bolts very tightly, allowing some amount of twist but no up-and-down movement.The holes in the rubber block are undersized such that when the bolts clamp it all together the rubber squish-locks (!) the bolts in place. Hope this helps.

Offline JEFF/21C

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Re: Tranny supports?
« Reply #2 on: January 22, 2024, 07:36:46 AM »
I've always used a flexible mount, and don't like that amount of weight hanging off the back of the motor , have also seen problems occur when mounted solid

Offline wideopen231

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Re: Tranny supports?
« Reply #3 on: January 23, 2024, 03:45:49 AM »
 I can't say I have seen a glide with a rear mount in any drag race car. Not saying nobody does it just have never seen and that means huge percentage do not have
 I am talking mostly door cars and rear engine dragsters. WIth the transmission being in the cockpit on FED and that only part with real spec it probably has less flex than any other style car. That said the front of the motor is in an area with a good amount of flex, most further out about still flexs.

 Anohter thing IMO is why carry extra weight that is technically doing nothing beneficial. Just my 2 cent and probably over priced.
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Offline Ray Hadford

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Re: Tranny supports?
« Reply #4 on: January 27, 2024, 05:33:50 PM »
Highly recommend rear trans support cross member. 

Our Dedenbear glide case is full length with a rear mount. Our motor is out 52 in... our car is a 225 inch ,  2002 Spitzer  FED....with a 388 supercharged small block on methanol. It runs 6.70s and 205...  We used to run nat. asp...  A/ND and Jr Fuel...    The drive shaft is Mark Williams with Greek couplers on the rearend and trans. , secured by clamp collars, leaving 5/16 front to back clearance in the drive shaft assembly..    Google ...Hadford Racing and car picts.  will come up.

The transmission mount is a heavy duty urethane style mount..... it is two metal plates molded to a urethane block, not solid metal mount. Jegs and Summit have them...... about  $35.00

The lower side of the mount bolts to a plate that is welded  to a slip tube that runs parallel to the drive shaft...  This tube set up is a front to rear slip joint...  tube inside tube set up. 

This set up provides  support for up and down and side to side movement, but does not restrict front to back movement.  ( motor plate flex)...

Our car is  sub  1.0 sec.  60 foot capable and all has survived for hundreds of runs... over the years.

Ray Hadford

Offline Finnish Fireball

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Re: Tranny supports?
« Reply #5 on: January 31, 2024, 08:57:30 AM »
I have shorty PG without support, zero issues. But with full length case I'd do like guys above. Support it but not totally solid.
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