[e90yyc]

How hard is it?

This post was formerly asking about CHF-11s compatibility for stop-leak products, but I've given it some more thought. I'm fine with accelerating my rack failure if it dies a quieter death, but I'm not interested in replacing every hose in my PS system in the event a product damages them.

Sooo, there seems to be little info out there about xDrive owners doing rack replacements. Anyone here done this, and if so, can you advise as to difficulty/time required?

TIA

[hassmaschine]

This is like a $4000 job at an Indy shop (had ours done due to a curb incident). So I'd say, it's pretty damn hard.

[e90yyc]

Originally Posted by hassmaschine

This is like a $4000 job at an Indy shop (had ours done due to a curb incident). So I'd say, it's pretty damn hard.

I kinda figured as much. Even if "only" half of that is labor... yikes... That's like $6k CAD.

I can't believe I'm saying this, but I've actually been contemplating one of those PS stop leak products... From everything I've read (and know...), it's a terrible idea though. My system isn't even leaking, so I've been told the noise likely originates from internal sealing issues... The only reason I'm considering doing this is because addressing the root cause of the noise is utterly unjustifiable economically, so if I can let the rack die a slightly quieter death, then I'm in.

If this is going to cause me major issues—and I kind of suspect it's not worth finding out—then I'll just live with the noise. Before anyone crucifies me, the idea of avoiding fixing a costly (but nonessential) problem at the risk of potentially creating an even bigger, more expensive problem that WILL have to be addressed is not lost on me.

My next course of action is to try some Lubrizol additive. Mercedes actually uses it officially (I had a friend of mine at Benz order me a bottle), so I have less hesitation about putting it in. It's just 50ml and will supposedly either help or not do much of anything. One TSB that refers to it is here. From all the research I've done, it's compatible with CHF 11s.

As it

[hassmaschine]

You can flush the system. Probably worth trying if it's not leaking, and way easier.

The reservoir, which many here probably don't realize - has the filter built in. It does wear out eventually (though I have never replaced one). So get a new reservoir, replace the fluid, and see what happens.

Our rack was replaced by insurance. I wouldn't want to foot that bill out of pocket...

[e90yyc]

Originally Posted by hassmaschine

You can flush the system. Probably worth trying if it's not leaking, and way easier.

The reservoir, which many here probably don't realize - has the filter built in. It does wear out eventually (though I have never replaced one). So get a new reservoir, replace the fluid, and see what happens.

Our rack was replaced by insurance. I wouldn't want to foot that bill out of pocket...

Done all that already sadly. New reservoir a while back. Flushed system a couple times too.

Appreciate the input nonetheless!

[hassmaschine]

Could the pump be bad?

[e90yyc]

Originally Posted by hassmaschine

Could the pump be bad?

I doubt it.

The original pump (at around 175k miles) was quite noisy. I replaced it with a 100k mile used unit. This solved part of the noise. Also replaced reservoir and changed fluid.

About a month ago, I replaced it again with a brand new unit. Still making noise, but perhaps verrry slightly less so. Just to be 100% sure, I had the pump replaced under warranty, so I’ve currently got another new pump sitting here waiting to be installed.

The chances of this new pump being noisy are pretty much zero, but I do expect I’ll still hear something given my experience with this issue so far. So that really only leaves the rack, no?

[hassmaschine]

Or air in the system?

It's been ages since I've bled a BMW steering rack, although I remember it being pretty easy.

Tbh, unless you like pain and suffering, and the steering is ok - I'd just try to live with the noise.

[e90yyc]

Originally Posted by hassmaschine

Or air in the system?

It's been ages since I've bled a BMW steering rack, although I remember it being pretty easy.

Tbh, unless you like pain and suffering, and the steering is ok - I'd just try to live with the noise.

Lol. Only a bit of pain and suffering. I do own a BMW after all.

You know, maybe it is? I know when I refilled the system I did run the reservoir dry very briefly. I’d think the air would have worked itself out by now though, no? Revisiting that isn’t a bad idea. I’m not sure how to bleed it though tbh. I’ve looked in reservoir and fluid definitely doesn’t look frothy, but perhaps it’s more subtle than that.

I do hear a slight metallic grinding noise, which seems to be worse when I turn my wheel to one side vs the other. One of the many reasons I suspect the rack.

[hassmaschine]

IIRC, you just turn the wheel lock to lock a bunch of times. But it's probably shown in the TIS.

[e90yyc]

Originally Posted by hassmaschine

IIRC, you just turn the wheel lock to lock a bunch of times. But it's probably shown in the TIS.

I’ll take a look at TIS. Probably want the wheels off the ground I’d guess.

Thanks for your help and input!

[PhaseP]

Originally Posted by e90yyc

How hard is it?

This post was formerly asking about CHF-11s compatibility for stop-leak products, but I've given it some more thought. I'm fine with accelerating my rack failure if it dies a quieter death, but I'm not interested in replacing every hose in my PS system in the event a product damages them.

Sooo, there seems to be little info out there about xDrive owners doing rack replacements. Anyone here done this, and if so, can you advise as to difficulty/time required?

TIA

On XDrive the rack is on top of the sub-frame.

I haven't done this, but it should be less difficult than XDrive engine oil pan gasket replacement, because I think you can remove the rack without completely dropping the sub frame down, just lowering maybe enough. If so, no need to disconnect the right and left spindles, axles and anything related to them, which oil pan replacement requires.

You would need to support the engine from top. You may be able to just support the engine from below too from under the oil pan, but not sure how stable that will be. If I were to do this, I would support from top mainly and then from under at the oil pan for 2nd safety measure.

You will need to remove the coolant line that is attached to the front of the subframe, and some other things too that I can't recall to be able to lower the subframe as much as possible.

Removal of tie rod ends, power steering lines, steering column joint, would be same as any steering rack replacement.

[PhaseP]

I would look for a DIY for other people's experience. If lowering the subframe won't be enough to pull the rack out, you are looking at same job as engine oil pan gasket replacement.

[mecheng77]

I had a car with leaky valve seals and it was worth replacing them and
ATP AT-205 actually worked, you can use it in PS systems as well. As long as the seal is not damaged, it works.

[GearHead335i]

Just follow an xDrive oil pan gasket diy up until you remove the 2 bolts holding the rack to the subframe. I just did this on my 2009 and I don’t see why replacing a steering rack would be $4000. I would just bite the bullet and do it if you are mechanically inclined.

[gbalthrop]

Originally Posted by e90yyc

...The original pump (at around 175k miles) was quite noisy. I replaced it with a 100k mile used unit. This solved part of the noise. Also replaced reservoir and changed fluid. About a month ago, I replaced it again with a brand new unit. Still making noise, but perhaps verrry slightly less so. Just to be 100% sure, I had the pump replaced under warranty, so I’ve currently got another new pump sitting here waiting to be installed. The chances of this new pump being noisy are pretty much zero, but I do expect I’ll still hear something given my experience with this issue so far. So that really only leaves the rack, no?

I don't recall having seen your description of the noise, when it occurs, and WHERE it appears to originate. If the noise is the typical "groaning" noise of a P/S pump, particularly when turning the wheel with vehicle stationary, louder at full lock, etc. then I don't know HOW the rack could be the cause (NOT leaking -- checked boots at either inner tie rod / rack seal I presume?)

When you changed the Fluid Reservoir, did you also inspect, remove, blow out, etc. the fluid supply line from reservoir to pump? Just as with a clogged screen in the Reservoir, any restriction elsewhere in the supply will cause the pump to "cavitate" or "groan" when high rate of fluid flow is required.

If the noise is a creaking or squeaking type of noise coming from the rack, then I would remove the gaiters/ boots and examine the rack/ inner tie rod at full-lock L & R for any sign of wear, at point shown as "6" on this TIS diagram:
https://www.newtis.info/tisv2/a/en/e...tions/KWDPzipo

If you can safely do this from above the rack (I've never tried on 328xi) try to listen to rack with mechanic's stethoscope (without getting hung-up in Serpentine Belt or Radiator Fan) to determine source of noise.

I haven't seen anyone recommend this on a BMW forum, but it used to be accepted practice with Jaguar "Power-Racks" to put about 100 cc of gear lube in the gaiters at installation, to lubricate the outer seals of the rack tube where the rack slides, and prevent rusting/corrosion of the rack end. I don't know any reason that would hurt a BMW rack, which is basically the same design.

Of course inspect that area for any corrosion, particularly if any history of gaiter failure allowing ingress of moisture/salt. If corrosion found, clean off & use gear lube (externally to rack ONLY ;-).

Other thing that occurs to me: What was the nature of failure of the original P/S Pump? Was it run low on fluid, and/or was there any sign of internal failure? When you replaced the fluid reservoir, did you inspect the screen or filter at the supply hose fitting to see if it was still intact, contained any debris, was clogged, etc.? Determining the CAUSE of an issue should always be the focus of any repair, but most of us just "swap & hope."

When "Pumps" (including A/C compressor which is essentially a pump) fail, there is always a chance of shrapnel being introduced into the fluid system, which can damage other components, including replacement pumps, and therefore many warranties state they are void if the system is NOT FLUSHED to remove any such shrapnel.

I have NO IDEA if there is any reasonable way to "backflush" the rack or fluid hoses. I spent a few minutes trying to figure a way to drain or flush the fluid from my 328xi rack, and just said "bucket" and used a syringe to remove old fluid from the reservoir, and like A/T drain & refill, figure doing that every 2 years or so will get MOST of the old stuff out. In your case, ruling out shrapnel in system MAY require more.

That said, if the rack is NOT leaking at either end (there has NOT been seal damage) then the chances of any serious issue WITHIN the rack don't appear to be great to me. As stated above, I would first try to identify the type, causative events & SOURCE of the annoying sound.

Please let us know what you find,
George

[e90yyc]

gbalthrop

George, thank you as always for such helpful responses!

Lots to consider. I have the new pump at home but have yet to install. I didn’t notice anything too funky when I changed the original pump a few years ago, but I might not have been looking close enough.

Last time I changed, I flushed out a solid quart of fluid. Unfortunately due to xDrive clearance, accessing the banjo bolt at the rack is off the table.

Not the slightest leak to speak of over the past two years... Strange, right? It was posited that perhaps there is an internal leak, which seemed to make sense.

Is there some way for me to blast out the lines, like one would blow out their underground sprinkler system before the winter!?

I’m open to anything at this point, as rack replacement will be an absolute last resort. I’d definitely try the gear lube, and will be adding the MB Lubrizol additive.

Is there a method you can recommend for inspecting my fluid for debris? I’ve checked before, but perhaps I’m being too lenient or using poor methodology.

This will be the fourth PS pump, so there’s no way this new one will be noisy unless there’s something bigger at play. Attempts to use screwdriver stethoscope against PS pump have provided mixed results. It’s too hard to tell if it’s the source of the noise. I can hear some of the noise through the steering wheel though, which to me would point to the rack, no?

Again, thanks for your help! I’ll be sure to follow up.

[PhaseP]

Originally Posted by Quinnhogue7

and I don’t see why replacing a steering rack would be $4000.

At dealership it is possible, $2000 for dropping off the subframe, $2000 BMW branded, dealership priced rack plus other parts replaced.