I ordered a removable crossmember from IPSCO which is on the way. I have access to a four post lift to to get under the car. Should I cut the crossmember while the car is on four wheels or is it better to cut it jacked up? Thanks.
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Well I guess is better to FIRST push the new one in as hard as possible and as close as possible to the stock location - with the car on is weels! This puts pressur on the rails in drive conditions/engine weight. Then cut the old one out.
I do not have the add on.. but you will see if you even might put some (hand crafted) shims on as well, BEFOR you do any CUT..
Is the cross member adjustable?
Do you want to cut the existing cross member with the motor in place? Caution to the oil pan !!!
If you don't have a porta power then tap it or another piece of steel in place like Matt said....
Thanks for the feedback. I guess I am a little confused. My understanding is that people install the removable crossmember so they can remove the crossmember when they need to service the oil pan. My thought would be the the crossmember should be able to be removed when needed or it kind of defeats the purpose. I am not an engineer by any measure but I would think the frame rails would be less prone to flexing while not in the air. That being said, is the existing crossmember really there for lateral loads while driving?
ok I see..the removable is ment to ease access the oil pan as required. What I am saying is in oder to have the correct width of the removable you want to push it in with the original still in place, to see if it has a tight fit in YOUR APPLICATION - All Panteras a slightly different. If if it is somewaht loose add some shims. Do this with the car on its weels. Then you can lift it all up and do the cut. You might then need a device the widen the rails so the previously optimimzed removable can go in at the correct place. The current spacer is DEF to stabilize the two big rails! Hence my hint to make the removable as tight as possilbe toward the rails.
There are def chassis experinced folks on the forum to give you the static and dynamic implcation if the rail is too loose. The rear of the car is def susceptible to "deformation" under load - weight and torsion.
Yes, the cross member, original or removable, is there to absorb the lateral forces and prevent the rear axle from deforming.
When stationary, there are no lateral forces and it therefore only absorbs those produced by the inclined suspension springs if the rear wheels support the weight of the car, the chassis should therefore not or very little. deform.
In any case, to put it in place you have to remove, at least partially, the lower arm supports and for that the wheels must be in the air. But to tighten the bolts definitively it is preferable to rest the voture on its wheels so that the chassis is in the position as close as possible to the one it has in operation.
Once replaced, you will have to adjust the geometry of the rear axle and if the cross member pulls or pushes, it varies the camber, hence the advantage of having an adjustable cross member.
Although there are adjustable lower cross members available as part of the chassis stiffening kits, the IPSO piece is non adjustable. It sits between the forward rear a-arm bolts, on a lift or ground there should not be a lot of flex at that point as the frame rails are confined by the rear crossmember. Access and maneuvering definitely easier with the car in the air. I cut my support out with a sawzall, car on jack stands, engine in the car. If you have a 9-10 quart pan you'll need the removable parking brake bracket as well to allow the oil pan to be removed.
Thanks, everyone! I read a ton of prior posts but I think this will be helpful for the next guy.
That said I started grinding the spot welds (my first time) using a belt grinder per some prior posts and it went relatively painlessly. I will take some pics for posterity. Next I will grind them other side, then take out the saws all!
Hmm ..we have a car with 500 Nm out of the engine app 2500Nm at the shafts, this is tremendous "force" on the chassis rails. The center cross althoug in the middle of it (!) perfect fit is VERY evident ..All I can say. I still recommend measure the perfect fit with weels down - static mode. Might lead to no realignment. Then do the rest..as required.