Originally Posted by trader4 (Post 1031638)

Baloney. Have you even been under the car? There are 6 bolts that
hold the stiffening plate/cover to the chassis. That is all they do.
There are other bolts in a completely different location that are the same
part # that hold the stabilizer/sway bar mounting brackets to the chassis.

Originally Posted by StephenVA (Post 1031591)

Guys

The X5 had two different plates under neath our vehicles. The aluminum one used until sometime in 2003 and a steel one used after that point until production ended on the E53. All the 4.8is have a steel one. As far as I can tell all the 4.6is had a aluminum one. The 3.0 models had both but when they changed to steel, I have no personal knowledge.

Bolts: The factory used one time fasteners (nuts and bolts), that are torque to yield. Torque to XXX and then 90 degrees more. These nuts will then change their shape and "lock down" with greater force. Yes, they are expensive. 1 year ago they were $25 for a set. Now Higher. Can you use grade 8 bolts with lock washers and get a solid connection for the bars and structural rigidity? With only a few years of auto engineering education/experience, I would say "yep". But I would also post the "no testing done to confirm acceptability" clause.

Bottom Line: Do not use the old nuts. At least replace them with known good grade 8 and lock washers. Just for safety.

Most of us on the forum, are high maintenance DIY who go above and beyond what the normal owners do to 10 year old cars. A lot of us are not the first owners and have spent $$ to get them "just right" once again. The reason? We want everything to work correctly and not leave us stranded somewhere. I like to believe we are care takers of the things we own, not just "users". Hell, I even weekly wash and detail, Qtrly clay and wax my Minivan! :thumbup:

Originally Posted by StephenVA (Post 1031761)

Why is it that everyone gets the good looking Alloy plate and I got a nasty black steel one?

With the last posting, there goes my change date theory. Maybe some had what ever was laying around at the time of build or each assembly line had different suppliers? It would be interesting to hear of other later production models had either plate at the same time.

My X5 4.8is Build date: 6/2005----Black steel

Originally Posted by StephenVA (Post 1031761)

Why is it that everyone gets the good looking Alloy plate and I got a nasty black steel one?

With the last posting, there goes my change date theory. Maybe some had what ever was laying around at the time of build or each assembly line had different suppliers? It would be interesting to hear of other later production models had either plate at the same time.

My X5 4.8is Build date: 6/2005----Black steel

Originally Posted by bcredliner (Post 1031682)

It is beyond ridiculous for anyone to decide that they know more than the E53 design engineers.

I have been doing my own work for many many years. If I can take it apart I can put it back together. I have always applied the saying to know what I don't know---I never test it. There is simply no logic in not changing the bolts.

Originally Posted by admranger (Post 1031790)

I guess you should be thankful you don't have this flimsy, tin foil aluminum plate like some of this have. You know, the one with no strength. :rofl:

I suppose you could always retrofit one off a junkyard X5, but I'm guessing the 4.8iS has the steel plate for a reason. Man, that must be a PITA to put back on after taking it off. How much does it weigh?