Replaced Steering Rack

[82bmw633]

1998 M3/4/5

Rack was leaking so I replaced it with a rebuilt unit from the Rack Doctor. Also installed new outer tie rods/ball joints. I thought I had measured everything but the alignment is off. I’m hoping that it’s either air in the system and/or the poor current alignment but it is very difficult to turn the wheels when not moving. I’ve got about 10 miles on the car so perhaps it will get better over the next few days until I can get it properly aligned.

When moving there’s no issue. No binding or dead spots, just twitchy because of the alignment. I don’t recall the original rack behaving the same way.

I didn’t start the car when the wheels were off the ground to bleed the system. I did turn the steering wheel all the way left and right with the tires on and it was smooth while still elevated.

Any ideas? Hopefully it’s just the alignment.

[Greenday694]

When you replace the rack, did you replace the Reservoir? The reservoir has a filter in it. That might be clogged from metal and other particles from your old rack.
Also make sure you put the right fluid in it. The cap on the reservoir should tell you which fluid. Typically ATF. But there are some that require a different fluid.

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[82bmw633]

When you replace the rack, did you replace the Reservoir? The reservoir has a filter in it. That might be clogged from metal and other particles from your old rack.
Also make sure you put the right fluid in it. The cap on the reservoir should tell you which fluid. Typically ATF. But there are some that require a different fluid.

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Yes, new reservoir and line to the PS pump. Filled with Dexron III/Mercon. When I first started the car the fluid was pink from all the air in the system. Started to clear up. I’ve read that it might take a few days of driving to totally bleed the system.

[bluptgm3]

Yes several full lock to lock turns in a parking lot should clear all the air out.
Hopefully, an alignment very soon as the tires will not last long on a bad alignment.


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[82bmw633]

Tires are on their way out anyway. Was hoping to put off an alignment until I got new wheels and tires from Tire Rack.

[TostitoBandito]

Yeah you're gonna need an alignment regardless. Even you you measure carefully I promise your toe is gonna be off.

As for the bleeding, all you need to do is start the car and turn the wheel lock to lock a few times. After that, top off the reservoir and you should be good to go.

[82bmw633]

UPDATE:
Had the car professionally aligned. It was really heavy/stiff at low speed before the alignment. Could hardly turn it when not moving. Now after the alignment there’s no power assist.

I checked the fluid in the reservoir and it’s pinkish meaning there’s still air in the system. No leaks, no noise from the pump. I’ve done about 30 miles of city driving. No problems before the rack swap. This is very frustrating.

[blckstrm]

UPDATE:
Had the car professionally aligned. It was really heavy/stiff at low speed before the alignment. Could hardly turn it when not moving. Now after the alignment there’s no power assist.

I checked the fluid in the reservoir and it’s pinkish meaning there’s still air in the system. No leaks, no noise from the pump. I’ve done about 30 miles of city driving. No problems before the rack swap. This is very frustrating.

I'd reach out to Rack Doctor. I swapped my leaky rack for a non-rebuilt ZHP rack, swapped a junkyard rack into my friend's race car after someone (who will remain nameless) broke a wheel and bent the output shaft on the original rack, and then again when we swapped a non-rebuilt ZHP rack into the race car. The only time any of them felt weird was the 30 minutes between breaking the wheel and realizing the output shaft on the original race car rack was bent. A couple of turns lock to lock should have it feeling normal. It seems like something abnormal is going on here.

I'd call them and see what they can tell you.

[82bmw633]

I’ll do that. They’re closed until 8/26 but they apparently do check email.

[bluptgm3]

After sitting for a good period of time, what is the fluid level? There is a full and low ‘step’ in the cap.

https://www.bimmerfest.com/forums/sh...23&postcount=2


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[82bmw633]

After sitting for a good period of time, what is the fluid level? There is a full and low ‘step’ in the cap.

https://www.bimmerfest.com/forums/sh...23&postcount=2


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When hot it is at the full level (top mark under the cap).

[82bmw633]

The Rack Doctor responded promptly to my emails and suggested several things (recheck fittings, reservoir, etc.). So I’ll do those and see what happens.


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[82bmw633]

Convinced it’s the pump. Works fine with cold fluid but when it gets warm there’s no power assist at idle/slow speed. Push in the clutch and rev the engine and the assist returns. Reman pump (Rockauto) will be here next week.

[bluptgm3]

WOW!! I did not think there were any pumps in the supply chain!!


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[82bmw633]

WOW!! I did not think there were any pumps in the supply chain!!


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Rockauto only had one of the four brands available (other three out of stock). PartsGeek has a few I believe. Also available on eBay. Rockauto was $80 plus core charge.

[TostitoBandito]

You can also get pump rebuild kits, and I don't believe the rebuild process is too complicated. Though, for $80 I don't blame you for just getting one already rebuilt.

[RRSperry]

Not for nothing, but did you make sure that you connected the lines and pump correctly?

[82bmw633]

Not for nothing, but did you make sure that you connected the lines and pump correctly?

Yes. The banjo bolts are different sizes on the rack. I replaced the hose from the pump to the reservoir. I kept track and not everything was disconnected at the same time. However, that WAS one of the things I thought which could have been the problem.

[RRSperry]

I was just asking... I've done my share of dumb things... lol

[82bmw633]

I was just asking... I've done my share of dumb things... lol

I have a friend who is a BMW mechanic and he referred to my issues as ‘The Car Repair Spiral of Doom’!

[82bmw633]

Installed the rebuilt PS pump from Rockauto. Easy job. Was more careful with bleeding the system. Did a 10+ mile loop on local roads and interstate to get fluid hot. Everything seems to be fine.

When I replaced the rack it had power assist at idle and low speed but when the fluid got hot it went away. At least I’m assuming that was the case. But it works fine now. A few more trips and I’ll know for certain.

[blckstrm]

Nice! Glad it fixed it!

---

Spiral of Doom - whatever!

I keep thinking - it's only a spiral of doom if you can't fix it and don't get it back on the road. Or I guess if you have a consumption mindset - use it up and throw it away.

Knowing I was buying a car with 120k miles and it would probably need some remedial work, I originally planned on $2k / yr for repairs (not maintenance - I've never counted tires and oil changes, though I sometimes wish I'd kept track of that too).

I only went over twice - the year I bought my wheels, and then also had to redo my cooling system AND replace the driveshaft, and then the following year when I had to replace the clutch, and did the full detente refresh and installed an SSK. And that was the year and year after I did 20k miles in 6 months (took a job in Austin, took 6 months of commuting from Dallas until the house in Austin was finished). Lots of back and forth, and even drove across country and back. The mileage definitely took it's toll that year and the following year.

Overall, I have averaged $1200 / year, even including purely gratuitous upgrades (strut / x braces, M50 manifold swap, wheels, sway bars, glass headlights, etc). You back the "extra" stuff out, I've averaged $990 / year. That's either $100 / month or $83 / month. It would take almost 10x that monthly amount to make a monthly payment on a new something that's even remotely interesting.

You have to pay to play with any older car - thinking otherwise is just unrealistic expectations. But I think overall these things are pretty cheap for what you get.

[82bmw633]

Yup, I got an entire list I’m working through. Next up is new wheels and tires and then flywheel, clutch, and short shift kit. I bought mine with about 130k miles but it already had track suspension, front and rear stressbars, and x-brace. Previous owner kept up on maintenance. I have all receipts from his ownership.


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[Mless5]

Which one did you go with?

Installed the rebuilt PS pump from Rockauto. Easy job. Was more careful with bleeding the system. Did a 10+ mile loop on local roads and interstate to get fluid hot. Everything seems to be fine.

When I replaced the rack it had power assist at idle and low speed but when the fluid got hot it went away. At least I’m assuming that was the case. But it works fine now. A few more trips and I’ll know for certain.

[das borgen]

this reminds me I need to replace my PS lines