Front Reinforcement Plate Installation - Loaded Suspension Or While On Jack Stands??

[E46_M3_ZCP]

Been meaning to ask this for a while but if removing then re-installing the front reinforcement plate, should it be done with final torquing while the suspension is body weight loaded or while on jack stands? I've been doing it on jack stands as I figure that's how any professional mechanic would do it while it's on the lift.

[Obioban]

Body weight loaded.

The strut tower brace, too.

…. and the rtabs, and the rear inner rear control arm bushings.

All of the above is a lot of why I prefer a 4 post lift with a quick jack on it to a 4 post lift.

[E46_M3_ZCP]

Body weight loaded.

The strut tower brace, too.

…. and the rtabs, and the rear inner rear control arm bushings.

All of the above is a lot of why I prefer a 4 post lift with a quick jack on it to a 4 post lift.

Thanks Obi, not doubting you but as President Reagan said "Trust but verify", it is stated so in the Bentley manual right? I guess I'll have to remove and re-install it using my race ramps. Any permanent damage possible if installed on jack stands?

[Obioban]

Thanks Obi, not doubting you but as President Reagan said "Trust but verify", it is stated so in the Bentley manual right? I guess I'll have to remove and re-install it using my race ramps. Any permanent damage possible if installed on jack stands?

Don't know about the Bentley, but it's certainly in the TIS.

[terra]

I don’t see it explicitly stated in TIS. Only thing it seems to mention is not to drive without the brace. I’ve always installed it with the suspension unloaded. The other stuff you mention being different (though in the case of rtabs and inner bushings, if you replace with a ball joint, it doesn’t matter)

[heinzboehmer]

I don't see it in TIS either.



None of the bolt holes are slotted, so if there was any significant movement in the chassis/subframe/control arms/FCABs with the suspension unloaded, then the plate would be really hard to refit, no?

[oceansize]

None of the bolt holes are slotted, so if there was any significant movement in the chassis/subframe/control arms/FCABs with the suspension unloaded, then the plate would be really hard to refit, no?

This was my first thought. Everything lines up perfectly whether loaded/unloaded.

[Obioban]

Hmm. I swear I saw it in the TIS, but that’s pretty irrefutable.

[E46_M3_ZCP]

Going back to what Terra said, I fully understand the reasoning behind preloading of the OE/OEM rubber bushings in parts like RTABs, FCABs, etc. upon installing them into the vehicle in it's free or unloaded state as you want the press-fit rubber bushings to be in a neutral state with the suspension normally loaded and why this doesn't matter when replacing the OE/OEM parts with spherical ball joints equivalents but was just curious if there was any such logic behind the reinforcement plate.

So what was the final verdict? No need to preload the suspension before tightening?

By the way, where do you guys source your TIS information from? I've been using the Russian Translation BMW TIS website but I would certainly be down for a better source or comprehensive downloadable copy.

[old///MFanatic]

..was just curious if there was any such logic behind the reinforcement plate.
So what was the final verdict? No need to preload the suspension before tightening?

Nah. Nothing has rotated. Unlike when some rubber suspension components twist.

I’ve read the TIS many times and never recall seeing that listed.

The Bentley Manual also has nothing stated about it. In fact the photo used in section for the M3 shows a four point lift used.