Offset Transmission Crossmember

[BruiserOutdoors]

well I haven't made much progress. I loosened up all the motor mounts and ratchet strapped the t-case to where I thought it needed to sit, tightened everything up, then loosened the ratchet strap to see if everything would stay put. It didn't.

So my next move is to try stock motor mounts (currently using WH Extreme Motor Mounts) and see if it still "wants" to sit crooked.




A good friend/life long mechanic told me that I am overthinking it. He said to leave it crooked (as this is normal for the vintage of vehicle) and build the crossmember accordingly (put the cross bar perpendicular to the frame rails). He thought it might strain u-joints but not the solid mass parts (transmission/t-case).

 

[nvrstuk]

Can you swap those HD mtr mounts side to side?

Otherwise, weld that crossmember up at 90deg to the frame like we'd talked about and because of the dbl carden design you have no concerns about DS angles. None. So give us a report tomorrow night on how it's running!!

 

[BruiserOutdoors]

This thread linked below is very relevant and well timed with my issues. Having the same issues with my WH Extreme Motor Mounts. It kicks the transmission towards the driver's side for some reason.

Why would the extreme motor mounts cause this shift? That has me puzzled. Is it because the stock motor mounts are staggered and these aftermarket ones aren't? (not sure if they are or not, they are not sitting in front of me to analyze).



I attempted to swap motor mounts last night but it was impossible with the body still on, and the transmission/tcase attached to the motor. couldn't get all three pieces raised up enough to swap mounts (fought things hitting the firewall). I will have to drop the transmission and transfer case out, lift up the motor alone, and swap mounts. This 6r80 and atlas combo is a beast to manhandle, not looking forward to dropping it off the motor (for what seems to be the 10th time now).

This thread has me convinced to take the extra effort to swap motor mounts to stock.

https://classicbroncos.com/forums/threads/4r70w-crossmember-trouble.316887/

 

[nvrstuk]

You can't unbolt frt/rear mtr mounts, the slide the engine fwd two inches or enough to raise it so you can jam the engine to one side and remove the opposite mtr mt and then repeat?

Beats pulling a 213 # 6r80 & tcase if you don't have to.

I just don't see why this wouldn't work as I've had to do it.

 

[BruiserOutdoors]

You can't unbolt frt/rear mtr mounts, the slide the engine fwd two inches or enough to raise it so you can jam the engine to one side and remove the opposite mtr mt and then repeat?

Beats pulling a 213 # 6r80 & tcase if you don't have to.

I just don't see why this wouldn't work as I've had to do it.

I could with the drivers side mount but the weight of all three pieces is heavier than I can manhandle and it just "falls" against the firewall as soon as the mounting stud clears the frame. And I wasn't able to lift it high enough on the passenger side to get it to come out of the frame mount, it would start to lift up the whole bronco.

 

[BruiserOutdoors]

UPDATE:

After an absolute slug fest wrestling the whole combo (motor, trans, tcase, transmission jack), I was able to swap motor mounts with stock ones, without pulling the trans off....Used some ratchet straps and made things work after a pep talk from NVRSTK. The fight began when I was trying to reinstall the motor. Valve covers got trashed in the process (lesson learned). as did the firewall. Few hours later, it fell into place.

The setup is much happier with the stock motor mounts. It is not so "stiff" aka no binding! I welded up the cross member and taking it to a fab shop tomorrow to get a completely new one worked up. This go-around the brackets and cross bar ended up too short so gotta start over with some new metal but the rough dimensions are present on the mock up crossmember.

Finally.. some progress!! Will post some photos of the finished product in a few weeks. There will be some back and forth with the fab shop on the final version of the cross member.

Thanks for all the input and advice Bronco Brothers!

 

[chris]

UPDATE:

After an absolute slug fest wrestling the whole combo (motor, trans, tcase, transmission jack), I was able to swap motor mounts with stock ones, without pulling the trans off....Used some ratchet straps and made things work after a pep talk from NVRSTK. The fight began when I was trying to reinstall the motor. Valve covers got trashed in the process (lesson learned). as did the firewall. Few hours later, it fell into place.

The setup is much happier with the stock motor mounts. It is not so "stiff" aka no binding! I welded up the cross member and taking it to a fab shop tomorrow to get a completely new one worked up. This go-around the brackets and cross bar ended up too short so gotta start over with some new metal but the rough dimensions are present on the mock up crossmember.

Finally.. some progress!! Will post some photos of the finished product in a few weeks. There will be some back and forth with the fab shop on the final version of the cross member.

Thanks for all the input and advice Bronco Brothers!

Glad my thread on the Cross Member and Stock Motor Mounts helped to point you in the right direction. I was really surprised at the difference between the stock and Extreme Motor Mounts pushed the alignment of the motor around. Maybe someone at Wild Horses should take a better look at that product and see what's going on. I went with those because I has a set of stock ones break on the trail and didn't want to go through that again.

 

[BruiserOutdoors]

Glad my thread on the Cross Member and Stock Motor Mounts helped to point you in the right direction. I was really surprised at the difference between the stock and Extreme Motor Mounts pushed the alignment of the motor around. Maybe someone at Wild Horses should take a better look at that product and see what's going on. I went with those because I has a set of stock ones break on the trail and didn't want to go through that again.

I have heard of stock ones breaking. What causes it? Too much torque?

I went with them for that reason and to gain some clearance for the explorer front dress. The extreme mounts appear to match the stock ones, other than height. Having a hard time picturing how that would mess with the geometry

 

[nvrstuk]

Just rednecking here...

Tranny jack under the tran and another under the Harmonic balancer with a safety floor jack or cherry pi kernel connected to the engine.

I have just the cherry picker in the next pic and it balances out fine

 

[nvrstuk]

My post above didn't seem to go thru till this am?? Posted it yesterday- I thought. lol

Oh well, you fought the fight and won!!

 

[BruiserOutdoors]

My post above didn't seem to go thru till this am?? Posted it yesterday- I thought. lol

Oh well, you fought the fight and won!!

What motor mount setup have you used in the past and currently? What has been your experience with stock?

 

[nvrstuk]

I use stock mts. Make sure they have the rivet that goes thru to keep them from separating in half if the rubber fails. I have talked to 2 different guys that work at Bronco houses we buy parts from that they went back to stock after the HD mounts transferred a very noticeable amount of vibration through to the frame.

For insurance I am going to & this will sound a bit crazy maybe, but I am going to put a HD worm clamp on either side of the mtr mt. I have found out that they can hold a ridiculous amount of load. Cheap insurance, sleek looking compared to the old skool pc of chain we used to use on our BB 454 Chevs and 455 Pontiacs when we tore those decades ago..