How necessary is a transmission mount pad?

[swatman260]

When I mocked up my engine and transmission in my chassis, I did so without a mounting pad. I've now purchased a pad, but it's thicker than I expected. As a result, the transmission now hits the floor of my bucket. Is this mounting pad necessary or is it acceptable to bolt the transmission directly to the transmission crossmember? If it matters, I'm running a BBC 454 and a TH350. Thanks for the advice.

 

[Mike]

If you are using rubber motor mounts, absolutely do NOT tie the trans case to the crossmember without rubber. You will break the trans case in a New York minute.

 

[flmnwlf]

I agree. That little twist the first time you step on it and bang!!! Ya pushin it home

 

[benT]

Agree with the above - unfortunately, I think you'll need to refab your mount.

 

[swatman260]

That's what I was afraid of, and why I asked. Sounds like I'll be cutting out some more of my floor. Thanks guys.

 

[choppedtop]

I think you would be ahead to redo the tranny mount. You will change the angle of the driveline, if add the mount and raise the tranny. I know its a lot of work, but you will be better off doing it.
Lee

 

[kcline40]

I don't know how your body is attached to the frame, but have you considered raising the body with a small rubber mount. If you are only talking about clearing an inch or inch and half wouldn't it be easy to shim up the body a little bit for some clearance rather than hacking up the floor. Couldn't you install a small piece of rubber between the frame rail and body. This would cushion the body and may provide the space needed to clear the trans and still may look good.


Good Luck.

 

[roadmonster]

Glass tunnel is cheap. Cut the old one out and start over. If tail of transmission goes up, rear end housing must go down to remain parallel.

 

[RPM]

Can you redo the cross member and lower it so the trans stays in the same place? Just make it lower to adjust for the thickness of the cushion.

 

[EX JUNK]

Can you redo the cross member and lower it so the trans stays in the same place? Just make it lower to adjust for the thickness of the cushion.

I think that is the most sensible way to do it.

Jim

 

[swatman260]

Yeah, I'm definitely going to redo the transmission mount to account for the thickness of the mount. While I'm not excited about the process, it's only a few hours worth of grinding and welding to have the peace of mind of knowing that it's done right.

 

[flmnwlf]

Glass tunnel is cheap. Cut the old one out and start over. If tail of transmission goes up, rear end housing must go down to remain parallel.

Ok I dont get this one?..

 

[bigblk1177]

You might be able to make some rubber bushings for the ends of your trans. mount ala mustang fox body type, then you could bolt the mount strait to the transmission. But it might be more trouble than its worth. Just an idea.

 

[bigblk1177]

Ok I dont get this one?..

Its really quite simple what goes up must come down!! Physics I think !! But I've been wrong before once. LOL

 

[choppedtop]

If the tranny is up 3 degrees, the rearend must be down 3 degrees. This is to keep the U-joints from shake, rattle, and rolling.
Lee

 

[Screaming Metal]

OK, heres the question. Dd you set up your drive line angle and pinion angle with the rear solid trans mounts? If you have aplasma machine OR a torch, your looking at 30 to 1 1/2 hours minutes cutoff and reweld time of trans mount depending on your setup.
Now, if you already have all the driveline set up, I'm with Ron, redo your rear crossmember to drop the trans. When you do this, your gonna have to redo your pinion angle. If not, your liable to have a bad driveshaft vibration if theres a misalignment.
I always say 'Measure 3 times and cut once, it doesn't take as much time to do it right than to redo things'....ALWAYS THINK 3 STEPS AHEAD! When building a car, something always interferes with something else....
Theres no quick way to do this, unless you redo your front motor mounts solid....then you will have to put up with the vibration. If your a hardcore racer type....it might be your cup of tea....

Best bet is to cut and reweld your trans mount, using the correct mount, then if your rear has a buggy spring you can use a spring taper shim to correct your pinion angle. But that will also mean cutting your hairpin/4-link or parallel bar brackets where they weld to your rear, unless you have adjustable ends.

 

[2old2fast]

IF the OP has the "usual " ladder frame , mounting the motor solid won't keep things from breaking , this style frame twists/flexes way too much for solid mounts !!
dave

 

[Screaming Metal]

I agree. That little twist the first time you step on it and bang!!! Ya pushin it home

Been there, done that! Bought a car, 69 Nova fire breathing 427 with Powerglide, 4.56's out back with some tall, wide slicks.
Ran it back down the road a little a little, jumped down on it, 'Ka-Boom!'....trans case let go....needed a mid motor mount

 

[swatman260]

Fortunately, its a relatively simple fix for me that will cost nothing but a little time. Since my driveline angles are already set, I'm just making up a new transmission hanger that is a little lower, to account for the thickness of the mounting pad. This way, the transmission angle doesn't change and everything is happy, happy, happy.