So I have the front bumper cover off, and want to start the top refresh, I have it on jack stands and need to know if it is OK to remove the cross brace if it is on stands?



The front end on stands.

 

I’m no expert on stress affects on the body, but your jack stand placement doesn’t seem wise.
A long way away from jacking point and putting a lot of weight on the front subframe.
Also, use of jack stands, almost fully extended, that don’t appear to have safety locks is risky.
Any yes, I know I haven’t addressed your question, but I don’t claim to know if removing the brace with jack stands in this position is a problem.
I do know it should be ok if the weight is supported at the jacking points.

 

The chassis -has- lift points on it.

I would use those....

 

Well I would think the lower “A” arm attachment would be sufficient to hold it, I have moved the jacks to the lift points also the rear tires where chocked.

 

It will hold it..but it puts more stress on the front of the chassis.

Use the proper lift points if you remove the brace.

Do this by the book..you priced out a windsheild lately?

 

Just replaced my OEM Porsche windshield from Porsche $$$$$$

 

Those antenna windshields are no joke when it comes to price. It's now the P# Porsche gives for all windshields for the 928 IIRC.

 

per the WSM, the cross brace is removed before lifting the car. However, for years, many people on rennlist swore you remove it only after lifting the car, as otherwise you could crack your windshield. I have always followed the WSM procedure, except in a few cases where I forgot, and I just opped it off once it was up on stands. The upshot is that you can remove it once the car is lifted, without an issue for the most part. Normally follow the WSM procedure, though.

 

This question has probably never been subjected to rigorous investigation, so there may be nothing more than "I've always done it this way to prevent [hypothetical problem]."

I don't think some permanent chassis-bending deformation is a plausible problem, but I kinda like the one about taking the brace off under one supporting condition and putting it back on under another. The shift might lead to an undesirable change in chassis orientation. On the other hand, we often don't know when it was put on, so we can expect a shift when it is removed.

It can be argued that the uneven business of jacking up a car one corner at a time puts your windshield at risk, more if the brace is absent. That's certainly a hypothetical (?) problem difficult to ignore, suggesting you wait until the car is raised. But uneven road surfaces can also twist bodies and put stress on any glued-in, "part of the structure" windshield; however, I've never heard a story like "I hit a bump and my windshield cracked." An existing crack might grow, sure.

Something else to consider is that our braces are thin-walled aluminum tubes — not very stiff, really. They're useful because shock towers are not naturally stiff in torsion, not as stiff as the body at and behind the firewall. Shock towers are like U-channels compared to a closed tube — floppy in torsion. Strut braces sorta close off the U-channel, in the direction of making the structure tubular, but not a lot — not much meat is there, and there's no meaningful attempt to brace the corners of this "tube". Still floppy compared to the windshield/firewall panel and the body to the rear. Yeah, this sounds a bit like bullish*t to me, too, but I have a license for it.

My "I've always done it this way" answer is, based on this thinking — that is, practical ignorance, though my windshield has survived me doing it twice — is to make sure the car is evenly supported (no twisting - hah!) and then remove the brace. And, of course, try to remember to put it back on before lowering, dammit.

More importantly, as said by others, assume your jack stands will try to kill you. Every 928 owner is precious!

 

For doing an Intake Refresh, you don't want the front of the car that high, unless your really really tall or like standing on a box

Using a Floor Jack placed centered on the lower Engine cross brace (where the steering rack is, Jack Up the entire front of the car evenly and place the floor jacks on the proper Jack points.
Then remove the upper cross brace, when your all done lower the via the same centered point, once the car is back on the ground install the upper cross brace.
After the car is settled (moved around to settle the front suspension) loosen and re torque the upper brace.
The key is not to grossly jack a corner with the cross brace off.

As for the extended stands, I'd be concerned if only the front is that high, not so much it the car was level (4 stands were used) to jack the back evenly use the rear cross brace.
With that said I'd place some other solid thing like a rim or even another jack stand so the car can not go flat to the ground

Dave K

Note: S4 and up w/ the factory front belly pan in-place, the Centered jacking as described above wont work as it covers the lower engine cross brace and you will need to be a bit creative until it's removed.

 

Doesn't need to be that high for an intake refresh.

IF you want the car to be that high, do yourself a favor and invest in a set of lift bars. Seriously one of the best investments i made when i bought my 928.

Good luck!

 

I'm 6.4, between my 928, 2 XKs and an XJS I always raise the front of the car for doing extended engine work. Always. Next days pain,,, that last longer and longer as I get older and older,,, have been a great teacher.

I'm my experience, much of the weight on in the front of these cars rests heavily on the front cross subframe.