Fabbing a tranny mount...

Take off from this thread....
http://www.naxja.org/forum/showthread.php?t=72417

Looking to make a low profile tranny mount. Liked the idea that of Jess's mount pictured. I was originaly thinking of making something similar to the model pictured, but wondering if it would better to have them mounted like Jess did. Rather then use the leaf spring as Jess did I was thinking of using two smaller bushing's welded to the skidplate and then using a similar upper mount as Jess did. Comments?

Not sure if this helps or not, but here's another alternative...this is in my friend's YJ build so the constraints are a little different, but the same idea could be applied to a higher-clearance crossmember.







It's basically two bushings, one on either side of the crossmember. The trans is hardmounted to the crossmember, and the bushings are relocated off to the sides. Depending on what material you use and what constraints you have on the inside, you can make a pretty high-clearance crossmember without the additional height of a trans mount between the trans and member.

I believe it's a set of poly spring-eye bushings he used, just found some tube they fit in and welded it, then welded tabs to the frame.

do you have any info on that brake on the yoke for the t-case. Thats kinda cool

scottsxj said:

do you have any info on that brake on the yoke for the t-case. Thats kinda cool

Click to expand...

He's running a GM 14FF rear w/disc conversion, so it was going to be very difficult to set up an e-brake on the axle. That caliper/rotor on the yoke is his e-brake. I believe he got it from Jesse @ High Angle Driveline.



Weasel, here's a clearer pic of what went on.

I've seen those setups and have decided against them for a couple reasons.

1) There's been plenty of disscusion on P4x4 about this setup and lots of people have broken different things due to these mounts. Theroies range but ones that make the most sence to me it that it would be difficult to get everything to line up correct and doesn't allow enough give for any errror in missalignment.

2) I don't think mounting such a bracket for the bushing on the unibody would be a good idea without some additonal plating or another bracket, making it more complex.

I'd love any new ideas!


I went to the dealer to get a replacement Trans mount... $88.92!!!

Why'd I go to the dealer? ...

The Napa replacement didn't fit!! the 2 'plate' bolts lined up fine, the 4 that go into the Xmember were offset by a 1/2" ... when I went back to Napa to return it, I asked if it was the 2wd mount, they said there's no difference between 2wd/4wd OR Manual/Auto mounts!

I need a new mount fast! I can feel my drivetrain!

Bowzer said:

I'd love any new ideas!


I went to the dealer to get a replacement Trans mount... $88.92!!!

Why'd I go to the dealer? ...

The Napa replacement didn't fit!! the 2 'plate' bolts lined up fine, the 4 that go into the Xmember were offset by a 1/2" ... when I went back to Napa to return it, I asked if it was the 2wd mount, they said there's no difference between 2wd/4wd OR Manual/Auto mounts!

I need a new mount fast! I can feel my drivetrain!

Click to expand...

I've gotten mounts from both advance and autozone that fit. IIRC it does matter which way it's put in, and it can be a pain to align the crossmember to framerail studs after replacing.

Weasel said:

I've seen those setups and have decided against them for a couple reasons.

1) There's been plenty of disscusion on P4x4 about this setup and lots of people have broken different things due to these mounts. Theroies range but ones that make the most sence to me it that it would be difficult to get everything to line up correct and doesn't allow enough give for any errror in missalignment.

2) I don't think mounting such a bracket for the bushing on the unibody would be a good idea without some additonal plating or another bracket, making it more complex.

Click to expand...

Fair enough, like I said, it's a YJ which makes it a different ballgame to us unibody folks.

FWIW though, the tabs on the frame rail were the last thing to be welded in the drivetrain. The motor mounts for the 454 Chevy were the first. We built the crossmember, put the tabs on it, and welded them where they wanted to be. A 454 and NV4500 trans (+atlas) don't exactly line up to anything.

As for #2. Let's say that your unibody had 3x3 angle plated the entire length of the frame rails, all the way from the front spring mount to where the rear 4-link conversion happened. Would you say that'd work? Reason being, I'm putting an NV4500 in my XJ with a fully reinforced frame and 4-link rear, and this is one of the methods I was considering. If you've got a reason it wouldn't work though, please let me know before I put too much time and thought into it.

The only real problem I see with those mounts, is that the bushings are farther from the centerline of the drivetran than the motor mounts are. This means that when your motors torques the motor mounts give a fair ways, but the tranny mounts can't take up the difference, as they'd need more movement due to the longer lever arm on them.


Hope you understand me. Either way, that's my reasoning for drivetran failures associated with this style of mount.

Yeah, that makes perfect sense. I don't know why I didn't think of that before. Durrr...