just completed a swap to an e36 rack, with a unit I rebuilt myself. This is my first e30 but I've rebuilt mx5 racks several times over the years, and they're virtually the same inside.
I bought a used e36 PS reservoir, mostly because it was cheap and included the low pressure hoses, which are pricey from BMW. Hooked everything up and filled the system with ATF, a little more than 3/4 of a quart of Redline Dexron 6 (D6)
When I started the car to begin the bleed - moving the wheel back and forth from lock to lock with the assistance of the running pump, there was obviously power assist going on. But when I would get to near full lock, it sounded like something was rubbing, a whine from the front. The closer to full lock, the more pronounced the sound, and the engine would almost start to stall. I couldn't see anywhere that belts could be hitting, and though my first take on the noise was that it sounded most like the fan scraping its shroud, it wasn't obvious that was happening either.
I ran through lock a good 15-20 times, then turned it off and checked the reservoir. There were lots of bubbles and the level was down, so I added more of the ATF. A few hours later I started the car again and went lock to lock another 15-20 times, with the noise being absent around the middle turn of the three from lock to lock, and rising and falling on the left and rightmost turn. Turned it off, still lots of bubbles in the reservoir, kind of like a very high temperature boiling pot of water. Not foam, but very tightly packed, small bubbles.
Then I took it for a drive. Around my subdivision with many turns there were no sounds or idle/engine behavior to indicate anything was wrong. The wheel turns smoothly and is definitely assisted. In cul de sacs I would take an angle to cause full lock, and at low speeds, the whine and funky revs were only present at or close to full lock.
The first variable in the mix is that while I was doing this job, I did a couple others. When I'd bought the car, it most needed steering and shifting help. The 5spd linkage was completely shot in every element. So I rebuilt that, changed out the completely split transmission mounts for 320i mounts, and the motor mounts (passenger side was blown, leaking), for oem style e36 M3 mounts. The new mounts are taller by a couple centimeters, with more offset studs. They fit, but seem to have raised the engine some from where it was. Whether where the motor was sitting at 200k miles and on blown mounts was the specified height, I do not know. But it led more credence to the idea that perhaps the cooling fan was hitting the shroud somehow at full lock.
But I can't see how the motor would move around in such a way as to make the fan hit the shroud, only by moving the rack back in forth while parked. And I'd think it would be even more likely to hit it when driving around corners at 25mph+ causing some amount of drivetrain roll. Which I'd done on the test drive. And it doesn't.
Nevertheless, I undid the shroud and looked/felt for any evidence of scraping on the shroud or the tips of the fans. Didn't find any. It did seem like the fan came quite close to the top as compared to the sides/bottom of the shroud, so just to see if it made a difference, I remounted the shroud a few mm higher than it had been to give it more clearance.
Later I took it on a longer drive, ten miles or so. In normal driving everything was still fine, steering was smooth, no noises that I could hear. on getting back I sat in the driveway and in place, moved from lock to lock again ten or so times. It would still complain loudly at close to full lock, though maybe 33% less than it had been doing when I first started to bleed.
So, I've got these things to consider:
1. Could I just need to bleed more, and maybe run a whole second quart through it?
2. Could I have used the wrong ATF? Is Dexron 6 compatible with an e36 rack?
3. Could dripping some oil on the PS V-belt when changing the engine oil filter have caused something so dramatic as this?
4. Could the engine sitting higher due to the e36 m3 motor mounts be causing the fan to barely touch the shroud.
5. Could I have connected PS lines/banjo bolts incorrectly
6. Could I be drawing in air at/near lock from bad seals at the air exchange line on the rack
The first - In searching on this subject I've seen one person state that they had to put two quarts through their system before they stopped seeing bubbles - and though the new rack was completely rebuilt/empty, and the secondhand e36 ps reservoir would have only seen ATF, unlike my stock e30 PS res, my power steering pump almost certainly had some old standard power steering fluid in it. The fluid in the reservoir was instantly a little darkened after my first bleeding session. So maybe pushing this stuff out and running in another quart of ATF is the way to go.
The oil on the belt question. I felt stupid when that happened, but wouldn't have expected this. I cleaned it off at once as best I could. Because the previous, original owner was well intentioned, if not an enthusiast, she did oil, belt, and filter changes on schedule, with receipts, albeit at the Jiffy Lube type places that use crap parts. So I do know that it was replaced almost exactly four years ago. So it should still be in the midst of its usable life. I'd also expect some screeching on start up, and maybe on throttle, and there isn't any.
The connections. I don't think I could have it out of order, because both the pump and rack each have two different banjo bolt fitting sizes - so one hose can only bolt onto one fitting at each end. In this case, that's the original e30 high pressure line connecting from the fitting on top of the PS pump to the topmost fitting on the steering rack. The other fittings each having a hose that goes up to the PS reservoir. I did use new BMW crush washers, one on each side of each banjo bolt. A search result thread had one post that mentioned the need to only use one crush washer on each banjo bolt, but it wasn't clarified why that was - the bmw diagrams always show two to be used. Anyway, I don't see any leaks anywhere, and no drip evidence under the car.
Lastly, the air lines. Those are the hard black plastic lines that run the length of the steering rack. As part of the rebuild, you have to remove one of the plastic bungs that push into the rack, in order to use the hole to pry out a metal retaining clip underneath. The reseal kits give you new O-rings for the air hose bung when it is pressed back in. If I'm not sealed fully at those bungs, which seem to be positioned on the rack such that they're doing whatever they do at near full lock, then maybe air is being drawn into the system and impacting the pump, causing the whine and making it more difficult to turn, perhaps even harder, which might explain why it can seem on the verge of stalling at full lock.
Sorry, information diarrhea, but I need some more experienced opinions to plan this attack, particularly since any one of those numbered factors above could on their own be a plausible explanation.
This issue aside, the test drive was just what I needed. When I bought the car the steering/transmission combined to make the driving experience downright unsafe. I bought the car based on the potential I could see underneath, but I wasn't going to use it until major changes were made. With the rebuilt linkage/custom ssk + poly bushings, the shifter is outstanding, and has gone from one of the worst I'd ever experienced to one of the best. The steering is also miles better than before with new inner/outer tie rods, the steering guibo deleted, and the Bus-like OEM airbag wheel replaced with a 360mm Nardi classic wood rim. It's only this godawful behavior at lock letting everything down right now.
Running another quart through the system wouldn't cost much, neither would a new belt. Worse case, I have a spare e36 rack and a spare rebuild kit for it.
Worst case, I'll depower the rack and live with it, possibly happily. I've also depowered miata racks, and enjoy them that way, just didn't intend for this e30 to be that kind of all-out no compromises type of car I've made those into.
I bought a used e36 PS reservoir, mostly because it was cheap and included the low pressure hoses, which are pricey from BMW. Hooked everything up and filled the system with ATF, a little more than 3/4 of a quart of Redline Dexron 6 (D6)
When I started the car to begin the bleed - moving the wheel back and forth from lock to lock with the assistance of the running pump, there was obviously power assist going on. But when I would get to near full lock, it sounded like something was rubbing, a whine from the front. The closer to full lock, the more pronounced the sound, and the engine would almost start to stall. I couldn't see anywhere that belts could be hitting, and though my first take on the noise was that it sounded most like the fan scraping its shroud, it wasn't obvious that was happening either.
I ran through lock a good 15-20 times, then turned it off and checked the reservoir. There were lots of bubbles and the level was down, so I added more of the ATF. A few hours later I started the car again and went lock to lock another 15-20 times, with the noise being absent around the middle turn of the three from lock to lock, and rising and falling on the left and rightmost turn. Turned it off, still lots of bubbles in the reservoir, kind of like a very high temperature boiling pot of water. Not foam, but very tightly packed, small bubbles.
Then I took it for a drive. Around my subdivision with many turns there were no sounds or idle/engine behavior to indicate anything was wrong. The wheel turns smoothly and is definitely assisted. In cul de sacs I would take an angle to cause full lock, and at low speeds, the whine and funky revs were only present at or close to full lock.
The first variable in the mix is that while I was doing this job, I did a couple others. When I'd bought the car, it most needed steering and shifting help. The 5spd linkage was completely shot in every element. So I rebuilt that, changed out the completely split transmission mounts for 320i mounts, and the motor mounts (passenger side was blown, leaking), for oem style e36 M3 mounts. The new mounts are taller by a couple centimeters, with more offset studs. They fit, but seem to have raised the engine some from where it was. Whether where the motor was sitting at 200k miles and on blown mounts was the specified height, I do not know. But it led more credence to the idea that perhaps the cooling fan was hitting the shroud somehow at full lock.
But I can't see how the motor would move around in such a way as to make the fan hit the shroud, only by moving the rack back in forth while parked. And I'd think it would be even more likely to hit it when driving around corners at 25mph+ causing some amount of drivetrain roll. Which I'd done on the test drive. And it doesn't.
Nevertheless, I undid the shroud and looked/felt for any evidence of scraping on the shroud or the tips of the fans. Didn't find any. It did seem like the fan came quite close to the top as compared to the sides/bottom of the shroud, so just to see if it made a difference, I remounted the shroud a few mm higher than it had been to give it more clearance.
Later I took it on a longer drive, ten miles or so. In normal driving everything was still fine, steering was smooth, no noises that I could hear. on getting back I sat in the driveway and in place, moved from lock to lock again ten or so times. It would still complain loudly at close to full lock, though maybe 33% less than it had been doing when I first started to bleed.
So, I've got these things to consider:
1. Could I just need to bleed more, and maybe run a whole second quart through it?
2. Could I have used the wrong ATF? Is Dexron 6 compatible with an e36 rack?
3. Could dripping some oil on the PS V-belt when changing the engine oil filter have caused something so dramatic as this?
4. Could the engine sitting higher due to the e36 m3 motor mounts be causing the fan to barely touch the shroud.
5. Could I have connected PS lines/banjo bolts incorrectly
6. Could I be drawing in air at/near lock from bad seals at the air exchange line on the rack
The first - In searching on this subject I've seen one person state that they had to put two quarts through their system before they stopped seeing bubbles - and though the new rack was completely rebuilt/empty, and the secondhand e36 ps reservoir would have only seen ATF, unlike my stock e30 PS res, my power steering pump almost certainly had some old standard power steering fluid in it. The fluid in the reservoir was instantly a little darkened after my first bleeding session. So maybe pushing this stuff out and running in another quart of ATF is the way to go.
The oil on the belt question. I felt stupid when that happened, but wouldn't have expected this. I cleaned it off at once as best I could. Because the previous, original owner was well intentioned, if not an enthusiast, she did oil, belt, and filter changes on schedule, with receipts, albeit at the Jiffy Lube type places that use crap parts. So I do know that it was replaced almost exactly four years ago. So it should still be in the midst of its usable life. I'd also expect some screeching on start up, and maybe on throttle, and there isn't any.
The connections. I don't think I could have it out of order, because both the pump and rack each have two different banjo bolt fitting sizes - so one hose can only bolt onto one fitting at each end. In this case, that's the original e30 high pressure line connecting from the fitting on top of the PS pump to the topmost fitting on the steering rack. The other fittings each having a hose that goes up to the PS reservoir. I did use new BMW crush washers, one on each side of each banjo bolt. A search result thread had one post that mentioned the need to only use one crush washer on each banjo bolt, but it wasn't clarified why that was - the bmw diagrams always show two to be used. Anyway, I don't see any leaks anywhere, and no drip evidence under the car.
Lastly, the air lines. Those are the hard black plastic lines that run the length of the steering rack. As part of the rebuild, you have to remove one of the plastic bungs that push into the rack, in order to use the hole to pry out a metal retaining clip underneath. The reseal kits give you new O-rings for the air hose bung when it is pressed back in. If I'm not sealed fully at those bungs, which seem to be positioned on the rack such that they're doing whatever they do at near full lock, then maybe air is being drawn into the system and impacting the pump, causing the whine and making it more difficult to turn, perhaps even harder, which might explain why it can seem on the verge of stalling at full lock.
Sorry, information diarrhea, but I need some more experienced opinions to plan this attack, particularly since any one of those numbered factors above could on their own be a plausible explanation.
This issue aside, the test drive was just what I needed. When I bought the car the steering/transmission combined to make the driving experience downright unsafe. I bought the car based on the potential I could see underneath, but I wasn't going to use it until major changes were made. With the rebuilt linkage/custom ssk + poly bushings, the shifter is outstanding, and has gone from one of the worst I'd ever experienced to one of the best. The steering is also miles better than before with new inner/outer tie rods, the steering guibo deleted, and the Bus-like OEM airbag wheel replaced with a 360mm Nardi classic wood rim. It's only this godawful behavior at lock letting everything down right now.
Running another quart through the system wouldn't cost much, neither would a new belt. Worse case, I have a spare e36 rack and a spare rebuild kit for it.
Worst case, I'll depower the rack and live with it, possibly happily. I've also depowered miata racks, and enjoy them that way, just didn't intend for this e30 to be that kind of all-out no compromises type of car I've made those into.
Comment