installing weld in sub frame connectors

[Brightyellow69rtse]

ok i got the motor and tranny all bolted inplace. the car is up on 4 jackstands. is there anything i gotta do before i weld the connectors inplace? i dont wanna just slap em on and weld em up and when i get the car down find out the doors wont open or close.  i gotta fit my 3" exhaust and x pipe too so i figure the subframe connectors should go in before that. tomorrow is gonna be a busy day. i actually worked on the car till about 10:20 tonight 

any tips would be great thanks guys!

[BBKNARF]

What I did to mine was park the car on a flat surface (garage floor) then jack up the rear end only, rear wheels off the ground and support
with jack stands. I had no problems with the doors opening and closing and plenty of room for the exhaust 

[ChargerST]

Where did you place the jack stands? the stands need to be under the rear axle and LCAs - otherwise the body is twisted slightly.

[BBKNARF]

Where did you place the jack stands? the stands need to be under the rear axle and LCAs - otherwise the body is twisted slightly.

Yes your right you do need to place the jack stands under the rear axle.

[HPP]

There are two pedominate schools of thought on this.

1) if your car is all assembled, completed, painted, and in driver condition, put the connectors in with weight on the susension members (4 stands-two under lower control arms, 2 under the axle) to duplicate normal static loads This ensure that nothing changes with panel alignment, allows gaps to remain consistent, and firms up the unibody structure in its "as used" condition.

2) Install in a "surface plate" type installement. This approach can be used if the car is apart or under construction- using up to 8 jackstands (2 near core support, 2 near firewall, 2 near rear crossmember, 2 near rear bumper), adjust all in heights in all position to be perfectly horizontal. Weld in connectors to lock in this corrected position.

[tan top]

 

with full weight on the wheels / suspension  !!
or as i done mine & empty  bare body shell  

[dangina]

with full weight on the wheels / suspension  !!
or as i done mine & empty  bare body shell  

is it beter doing it on a empty shell - I'm at this stage and was wondering if it would be better now or when the motor/tranny seats ect are all back i the car

[HPP]

If your body is a shell, now is the best time. This way you can get it up on stands and verify the position of everything. I found when my car was checked, it actually was curled like a potato chip. I had to load a bunch of engine parts in opposite corners of the car the spring back to proper dimensions. Then I welded in the bracing and everything was locked in to a more correct position.  Otherwise, I would have increased chassis regiditiy, but would have had differing amounts of preload on the suspension in each corner.

[Musicman]

Page #1 from Hotchkis...

http://www.hotchkis.net/_uploaded_files/4011S.pdf

[dangina]

Page #1 from Hotchkis...

http://www.hotchkis.net/_uploaded_files/4011S.pdf

Thats what I thought - I didn't know that the subframe connectors connected to the rear leaf spring brackets - I thought it was welded onto the rear frame rail...

[Musicman]

Thats what I thought - I didn't know that the subframe connectors connected to the rear leaf spring brackets - I thought it was welded onto the rear frame rail...

There are 2 or 3 different designs out there, consequently there are 2 or 3 different methods of attachment. They are all designed to perform the same function however, regardless of attachment points.

[elacruze]

There are two pedominate schools of thought on this.

1) if your car is all assembled, completed, painted, and in driver condition, put the connectors in with weight on the susension members (4 stands-two under lower control arms, 2 under the axle) to duplicate normal static loads This ensure that nothing changes with panel alignment, allows gaps to remain consistent, and firms up the unibody structure in its "as used" condition.

+1.

Be sure your door adjustments are as good as they can be, suspension is loaded as it would be on the tires, and install. Theoretically speaking, the frame connectors should have no load on them until you transfer engine power through the car.

[HPP]

I've read through the Hotchkis instructions and they are very good. I'd say their recommended approach is good for 98% of all the Mopar enthusiasts out there. No doubt they were put together with research from their technical staff and then subsequently reviewed by their legal staff. Keep in mind that if in any place in their instructions they even reference stripping your car to install their components, they could be held liable by some knucklehead who strips down his all original, numbers matching car then reassembles it incorrectly with old parts which allows the engine mounts to break, which then flops over and binds up the steering shaft, which locks the front tires in an oblique angle, which then causes the car to plow on to a sidewalk full of people. Yes, I can see why they recommend you leave everything in the car.

By contrast, every competition car that is a serious effort is built on a surface plate to ensure that all of its components are square, level and plumb. Why is this done that way? To ensure the chassis provides the most stable, consistent, repeatable platform to the suspension. If you build a chassis just hanging out in space, the heat of welding will cause the components to move around and change their spatial relationship to other components which then will create a situation where chassis response is not consistent from side to side nor end to end. Not an ideal situation when you trying to tune a chassis for maximum performance.

With that said, do you need to strip the car down to install frame connectors, no. However, if your car is already all apart and a shell, it only takes a little more effort to put it in a state that will create a better starting point from which to begin. Do you need to do this, again no. Do you want to do it, it depends. What is your intended usage and how in tune with the car are you? If you are a driver who can feel the difference in chassis oversteer that results from fuel load changes in full tank to a half tank, then you might notice the difference in an unequal chassis. If you never push  your car harder than the occasional trip down the dragstrip at the local mopar show, then you probably won't notice the difference in equal or unequal chassis reaction, but you will definitely notice the increase in rigidity and consistency of panel alignment that results from installing connectors.

So decide how your going to use your car, how important consistantcey of chassis reaction is to you, and decide what is the best approach to use. I'm not saying either one is right or wrong, just that each way has its advantages and drawbacks based on driver and usage. Understand those before you jump in.

[Musicman]

By contrast, every competition car that is a serious effort is built on a surface plate to ensure that all of its components are square, level and plumb. Why is this done that way? To ensure the chassis provides the most stable, consistent, repeatable platform to the suspension.

This is also done with the end product in mind... much the way that some flatbeds designed for carrying heavy loads are designed with an arched back knowing that it will level off correctly if the designed maximum weight is applied. These platforms are designed to sit correctly once fully loaded, which brings us back to the principle behind the Hotchkis instructions for adding frame connectors "after" the fact.