transmission mount

[hemidakota]

Is it bad to have tailshaft of trans solid mounted to frame on a fed? I have read all about no mount to must have some cushion in the mount. The FED I help out with has never had mount bolts in it, just sits on cross member. Last time out it wiped out the tail shaft bushing. If mount is bolted up everything lines up perfect and coupler slides back and forth smoothly. Would it be a bad idea to bolt it down? I have pics and will down size them and up load them soon.

[dreracecar]

My only expierience is with High HP cars,  The engine moves around a bunch at launch even though it tied in very well. High possability of cracking the trans case if one bolts the tail housing to the chassie. 20 years of not running a rear mount and just letting it hang off the back of the engine.

[hemidakota]

Do you use a shorty glide or a regular glide? Sorry just trying to learn. Bushing or Needle bearing in output? Wiped out a nice Teflon coated bushing in 8 runs is why I ask, with no mount bolts.

[gregm784]

Some info, may or may not apply.

I ran a 8 second mild steel chassis Nova, and never had a rear trans mount.  It hung off the rear of the motor (motor plates) only.  Full length glide. Stock case.

Ran a late model circle track car, no trans mount, hung off the back of the motor only (motor plates).  Full length glide. Stock case.

My 7 second dragster has a shorty glide, never had a trans mount.  Dedenbear case and JW case

Let it move.  no mount needed. 

[PSweeney]

I ran a mount in my previous altered.  Reid case and stock tail.  I put over 200 runs on it with no problems.  With my digger I won't be running one as it's a shorty box and as pointed out on here by Bruce and others it's a pain to mount off the governor or pan rails

[Tim Jones]

After breaking the tailshaft on the glide in this car , all the dragster guys told me to stop bolting the tail down , after that no problems, this was back in the late 70's when I had this car,, Tim Jones

[rooman]

I recently re-worked an altered that was trying to break the trans mount bracket off the cross member. The car had other issues (no uprights where the motor mounted etc) and when I fixed them I also cut the remains of the trans mount off the cross member. In the factory installation of a Chevy motor/trans the entire package hags off mounts near the front of the block and one on the extension housing so the transmission is obviously strong enough to carry a lot of load. As Bruce notes, even on a tube chassis car there is a lot of flex due to torque and mounting at three points (front, mid plate and trans) can have a tendency to tear things up. If letting the trans float is killing the bushing I would look at the chassis itself--it may be flexing enough to put excessive load on the coupler.

Roo

[hemidakota]

Thank you for all your input. Cannot find anything wrong with chassis. Should we cut the mount off?

[Dolmetsch]

Interesting thread. I always ran a mount but never solid. At the very least two layers of tire tue rubber under the trans pad with the bolts in and loctited or captured but not super tight however I ran torkflights which are in most cases long transmissions compared to a PG. I had one friend , engine customer, who said I was nuts and is constantly having to weld or replace his trans case because of severe cracking. Usually every season.
don

[dreracecar]

Yes cut that mount off,  I'm running a long glide and a standard tailshaft bushing

[Van]

Interesting thread. I always ran a mount but never solid. At the very least two layers of tire tue rubber under the trans pad with the bolts in and loctited or captured but not super tight however I ran torkflights which are in most cases long transmissions compared to a PG. I had one friend , engine customer, who said I was nuts and is constantly having to weld or replace his trans case because of severe cracking. Usually every season.
don

   This is how I have always done it . A soft pad under the trans mounting pad - never cinched down. I also make my mount as a bipod with small tube and a plate on top, this is never welded to the frame, just hose clamped to the frame. I have never broke anything or wiped a bushing.

[wideopen231]

Seems most say don't need mount and can actually cause problem. Seems win win. Cut it off less weight at no cost and possibly avoid damage to trans.

I have thought about making one and thought about it causing problem,decided not to do.For once my over thinking keep me from trouble and extra cost.That rarely happens.

[George]

No mount on ours and no problems. Full length glide.

[hemidakota]

Well it appears the mount is getting cut off. Thanks for all the input. Was thinking mount might be causing problem but there I go thinking again. There is no room for error on this one as for trans sits right on mount bolts or no bolts. Thanks again for all the input. See everyone at the HRR. Good times soon to come!