Jetdriver69

When I first started working on my 82, I thought I would save a few $ and get a rebuilt rack from a supplier other than "our" guys.

Well, when it was time to install the rack, I found the mounting tabs were clocked 45 degrees off from each other. Don't ask me how that happened and needless to say, you couldn't use it.

Then I had to call, complain, ship it back, get refunded and order one from 928 International.

All that for saving about $40, which more than cost me in being royally p*ssed off.

SeanR

The previous owner of your car did that with a fuel tank. He ordered a cheap replacement and I drove the 50 miles to his place to put it in only to see it was going to leak. He ordered one from Roger and we drove down again. It cost him twice as much to than it should have, if it had been done correctly the first time.

Can't tell you how many times this happens just to save a buck or two.

safulop

Hmm, a lot of facts are coming together for me here. My car has 18" Cup II wheels from a 911, and they do not have the correct offset. A couple of years ago I hit a sinkhole so big that the right front wheel is very slightly bent on the outer lip. Guess which end of the rack blew out? In future I will be more vigilant with the fluid flushing and boot replacement.

Jherriott

Having to do the same job with my rack, I found that you still can get new racks from the dealer. At 2K plus taxes... it's painful. I wonder *if* they are legit BRAND NEW... I still think I'm gonna go with 928 int.

AO

Are the rebuild kits any different between the earlier racks and the "low effort" kits? I need to do this on my GT.

SeanR

Just go with the rebuild units from Roger/Greg/Mark. You can't go wrong there at 1/3 the price.

dr bob

The main difference is the spring in the spool valve. That's the servo that the steering wheel attaches to, between the input shaft from the steering wheel and the pinion gear that reads rack position when power assist is available, and mechanical steering ability with no assist. The spool valve adds assist pressure to one side of the hydraulic cylinder when the ends of the spool valve are displaced from each other, as would happen when you turn the steering wheel. A weaker spring means more displacement is available for the same steering wheel effort, essentially providing easier steering.

Promo and tech literature suggesst that the later racks use "low friction" seals too.

Rebuild kits don't change the spring in the spool valve. These are visually identical, so rebuilders often put any valve in any rack. That in turn drives folks like Greg to rebuild the later racks one by one, so the valve stays with the rack that came in the car.

I think Nicole recounted a rack replacement effort that took two or three tries to get the right low-effort rack back into her late S4.

dr bob

Yes. The power steering is functionally unchaged throught the model's life. There is a change in length of the rack at one point, and the latest racks have a different low-effort spring in the servo/spool valve. IIRC there are three different pumps used, all the same type but with different mountings and pressure relief settings. Pumps do wear and are very easily rebuilt with new internal wear parts, meaning the "wear" debris is circulating through the system.

AO

Thanks Bob. Great info. I will rebuild with caution.

Rod Handsfield

I'm readying myself to attack my worn out steering rack. I'd like to order everything I will need in advance. What are some suggested WYAITs? Thanks and Merry Christmas, Rod Handsfield

123andrewe

hi

i have a 1989 928 s4 and the steering rack is leaking , what is best
is it worth changing seals , i dont do the work so i have to pay someone
or is it better to buy a recondtioned rack and have that fitted

Mrmerlin

Rod I would suggest that you buy a rebuilt rack from either Roger (he is closer so less shipping) or 928INTL,
dont mess with trying to rebuild the rack,
also you will need 4 sealing washers ,
a new reservoir tank,
(though I may have replaced this).
and the curved hose from pump to reservoir,
and 1 qt of Dextron. 4 or 5 or 6

also inspect the bellows if yours look old replace them,
and inspect the inner and outer tie rods,
if you find any play in the wheels at 3 to 9 axis,
then the tie rods should be swapped out

Bmw635

Any chance wrong fluid causing issues? Dexron, ATF , and other fluids are not the same. I've seen BMW power steering with wrong fluid causing servotronic failure which make heavy steering, lost of pressure control. The power steering pump leaks but steering box doesn't leak thou as it doesn't have rack.

I've seen folks added other kind of Power steering fluids to their BMW causing all kind of pump, box and servotronic issues.

My wife's X5 use ATF while my 740 use Dexron. My old 635 used Dexron 2 and leaked the pump when I mixed ATF. My Land Cruiser PS is leaking at the pump but not at he box, probably due to mixing Dexron(OE) and ATF.

Almost all BMW steering parts are ZF so seals are probably the same. The PS reservoir in my 928 is same as my 740.

UpFixenDerPorsche

My '89 S4 was 23,000km (15,000mi) when purchased. Now has 170,000km (105,000mi) (A couple of years of inactivity in there as well).

Needed new seals several thousand mi ago, remembering these were the original '89 seals. AT or PS fluid does the job.

WallyP

Porsche says Dexron, not PS fluid...