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Torsion bar alignment and crossmember

Started by Msbaugh440, April 05, 2023, 06:51:25 PM

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Msbaugh440

My project took a huge pause at this stage after having kids and I'm trying to pick it back up. I currently have the floor pans and the torsion bar cross member removed. I braced the car side to side in multiple locations after removing the floor pans, but before cutting out the crossmember and separating the crossmember from the subframe connectors. I took a ton of measurements and leveled the car and everything seemed to stay in place. Door gaps are all the same as well.

I'm trying to test fit the torsion bars to verify they slide into the LCAs appropriately, but can't get them to line up to get this thing welded in and the project moving forward. The happy spot where they slide in and out of the cross member well puts the torsion bars 1-1/2-2" above the LCA sockets, like shown in the pictures.

Could the car have tweaked this bad despite no evidence of that when removing the old?

Could the AMD torsion bar fitment or angle of the sockets just be off?

Or... do I really just need to spend more time with the crossmember mounting flanges and fitment better till it lines up?

I don't think forcing the bars in with this much offset and welding it up would be appropriate, but not sure how much "forcing" is normal on these old mopars. Thanks for the advice.

Msbaugh440


Msbaugh440



moparx5

feel fortunate you found the problem now. i had same problem but had all floors replaced and welled in. one side slid in fine the pas side i had to use a ratchet strap to pull it over enough to line it up and nock it in. i asume the cross member arent remade peerfect or atleaset some of them. i would tweak the cross member till they line up. mabe pie cut it in the middle or just outside the trans mount on both sides. you can rework the front frame rail tabs a little for the movement of cross member. honestly i was gonna remove the sockets inlarge the holes a little then make plates for either side of cross member the weld it all back up . make sure you mark the sockets so the flats of the hex stay in same clocked location or u may loose ride hight ajustment. i was in pretty deep on my project and that was the only problem i ran into dont let it slow you down work through it

moparx5

having re looked at your picture again,  roll the cross member down a little 1/8 of an inch at cross member will be about 3/4 to an inch down at other end of t bar you should get it pretty close. mine was pointing out towards frame rail , not straight up like yours.
there the old saying for restoration parts,,,,, they bolt right in,,,, hahahah they never do!!!

Msbaugh440

Good advice. I'll shim the rear flange of the crossmember an 1/8" at a time and see how that fairs. I suppose I'm paranoid about something having tweaked, but I don't think that's what's happening. The crossmember has needed some persuasion to get in place with a rubber mallet but nothing abnormal.

Msbaugh440

Well I removed and reinstalled the crossmember 5 or 6 times. There's really only 1 spot that it will fit. I finally just pounded the torsion bars in with a rubber mallet and a socket.

Is it completely wrong to have to smack these in with a mallet? There's no way that I was ever going to be able to line the crossmember and LCA sockets up enough to slide the torsion bars in and out by hand. Is that really a realistic goal?


moparx5

here is a long version
i would suggest tipping crossmember until bars line up more freely before welding anything you would be surprised how much the flanges on end or rails and crossmember can be manipulated. i agree they should slide in very freely so to achieve this  may take a little patience . try a speed screw in forward tab on cross member to top of rocker  and top flange into top flange on rails. use that as a pivot point, then push down on bars to and lock in front sockets. asses how much rear tabs lifted off top of rockers and how much space is between end tabs of rails to front face of crossmember. frame tabs will be tight at top and open at bottom. hammer dolly those tabs a bit to close this gap ,, work top of tab forward and bottom of tab back without  crossmember in your way. at same time you can work front flange up on crossmember because as it rolled down to align t bars that flange rolled down as well. u will need to work that uo to remain flat to new floor pans. once those front flanges are  tight and weldable tack weld in place then use a c clamp on top back flange of crossmember to bottom of rocker and use this to bring down to close gap to top of rocker. the rear flange of crossmember will probably need to be hammer and dollied up to meet new floor pan.
  at end of day u dont want a shit ton of preasure to get bars in , simpler solve is to either try get a new x member ( mabe that one is just junk ) but i have done quite a bit of metal work in my life its only metal, cut it bend it weld it back together , these parts arent perfect ,,, dont put that hammer away u arent done with that yet

PLY474

The body service manual has reference dimensions.  Not sure if this is helpful or not.  71 figures below.  https://mymopar.com/service-manuals/


Msbaugh440

I suppose I was getting in my own head. I got the torsion bars lined up to the point where I can get them sliding in and out by hand. Thank you #MOPARX5 your tips were great. Troubleshooting the alignment was a huge PITA though!

One of the braces I installed had the rear of the front frame sitting up slightly higher than they should have been. I cut it off and was able to lower them about 1/8", which rolled the torsion bar crossmember forward ever so slightly and lined the torsion bars up almost perfectly. I still have some hammering to do to line up some of the other flanges better, but I think I'm almost ready to start welding!!!

moparx5

thats great im glad  was some help. have patience, some of this stuff fits great and some of it needs a liitle love. get yourself some speed screws your gonna need them to suck that floor pan down and pre fit it !!!!
keep going at it!!!! your doing great