Steering Rack Rebuild ??

[PSUEng]

I grabbed a yellow tag 712 rack off eBay thinking I'd rebuild it with a seal kit--just something to mess with--clean it up and throw it on the shelf until my stock rack either leaks, or I do a full front suspension bushing refresh and throw it in. The rack arrived in visually very good shape. So I dig around, watch some videos, realize one can get seal kits--but, is it worth tearing into? The rack came out of a 133k mile car, I'd probably replace the hydro lines (easy) and re-grease rack gear; I don't see any leaking from the pinion or rack gear end seals. Is this a "let sleeping dogs lay" kind of thing, or are these worth tearing into? Right from the get go, I can tell BMW/ZF don't want you getting into the pinion with their 32mm(?) 12pt bolt, and 12 point "female" nut after you get that out.

Advice on what to do? Anyone rebuild one?

[PSUEng]

Gave it a good clean today--outside housing, rack gear and popped the black cap off--cleaned off the grimy grease inside on the input splines. No apparent leaks anywhere from the rack gear outer seals or input pinion seals; I may just replace the hydro pipes and call it good. The old fluid that came out was black, suggesting few--if any--PS fluid flushes had been done. Not sure if the gamble of older parts v. new part quality here is worth taking.

[bigjae46]

I bought a seal kit from eBay since I had a leaky pinion seal. It was kind of a pain, just pay attention to what parts come out in what order.

I think it is worth rebuilding especially if the rack is going to sit. The rubber is hard because of age then it will just shrink up and crack. Then you know it is ready for whenever you need it.

[davidinnyc]

I'm subscribing to this, and interested. I'll be picking up a 712 steering rack with ~60K miles, so will be doing a full cleaning and evaluation/potential rebuild if it's needed.

[chalaka]

I bought a seal kit from eBay since I had a leaky pinion seal. It was kind of a pain, just pay attention to what parts come out in what order.

I think it is worth rebuilding especially if the rack is going to sit. The rubber is hard because of age then it will just shrink up and crack. Then you know it is ready for whenever you need it.

Hi bigjae46, can you share which repair kit did you get from ebay?
any special tool is needed to perform the repair?

thanks

[bigjae46]

Hi bigjae46, can you share which repair kit did you get from ebay?
any special tool is needed to perform the repair?

thanks

Power Steering Rack and Pinion Seal Kit for BMW E46 1999-2002 ZF Rack | eBay

It was a long time ago and I only did the pinion seal. I'm pretty sure you need a small snap ring plier. Probably a seal puller or something to pull blind seals.

[PSUEng]

I'm subscribing to this, and interested. I'll be picking up a 712 steering rack with ~60K miles, so will be doing a full cleaning and evaluation/potential rebuild if it's needed.

I did some video watching and reading of the ZF rebuild manual, I think I'm going to just find a pro to rebuild this thing. I'm in contact with a place that will do it, but hesitant due to pricing and the fact that I don't want this thing sitting too long uninstalled after a rebuild; my current stock rack is still going fine. Anyway, quite a few special tools needed, technique, and so on. BTW, the Gates kit is NLA per my inquiry to them a few weeks ago.

[chalaka]

Power Steering Rack and Pinion Seal Kit for BMW E46 1999-2002 ZF Rack | eBay

It was a long time ago and I only did the pinion seal. I'm pretty sure you need a small snap ring plier. Probably a seal puller or something to pull blind seals.

thank you for the reply.

so, sounds like this is not DIY friendly as PSUEng explained ..

[9kracing]

Looks like RackDoctor is out of business. Or maybe the website just needs updating.

https://rackdoctor.net/

Too bad, they had such stellar customer service

[PSUEng]

thank you for the reply.

so, sounds like this is not DIY friendly as PSUEng explained ..

I should clarify, based on my skill / tools / and available time to mess with it. Others may have different successes. There are inner seals, certain fasteners, certain adjustments and so on that I just don't want to tackle.

I can't recall where I found the ZF repair pdf but it's online floating around if you search. Of course, that document covers pressure testing and a plethora of other things that one probably doesn't HAVE to do, but a rebuilder likely would as a matter of liability.

[Drewrivera]

This is a difficult task in my "Rack and Opinion"🤣🤣🤣. You would definitely need the right tools and skill for this. I personally ordered mine from CMP. I chose them because i didn't want to deal with that people's reviews and real life stories that were on rack doctor. When i bought mine from CMP Everyone seemed to be buying purple tags at the time for some me reason, but i chose yellow. Cost me between 6 to 700$.

[9kracing]

When i bought mine from CMP Everyone seemed to be buying purple tags at the time for some me reason, but i chose yellow. Cost me between 6 to 700$.

When I got mine from RackDoctor he had actual ZCP blue tag racks for $600. Granted, it took literally 6+ months to actually get it, plus two tense email conversations where he threatened to cancel my order... but I did eventually get it lol.

[bigjae46]

I should clarify, based on my skill / tools / and available time to mess with it. Others may have different successes. There are inner seals, certain fasteners, certain adjustments and so on that I just don't want to tackle.

I can't recall where I found the ZF repair pdf but it's online floating around if you search. Of course, that document covers pressure testing and a plethora of other things that one probably doesn't HAVE to do, but a rebuilder likely would as a matter of liability.

I don't think it should be that difficult. Bench vise, small seal pullers, and a properly sized snap ring plier. Maybe a press or seal driver.

[Bry5on]

I don't think it should be that difficult. Bench vise, small seal pullers, and a properly sized snap ring plier. Maybe a press or seal driver.

I see you have not rebuilt one! There is a seal buried in the middle of the rack that is a huge pain in the ass to remove. It will most certainly involve making a custom tool in the moment (that’s what I did for mine). If you’re not super confident with mechanical work, leave it to a pro for sure. This is probably the least straightforward job on the e46, including and not limited to an engine rebuild or vincebar install. Word to the wise.

[bigjae46]

I see you have not rebuilt one! There is a seal buried in the middle of the rack that is a huge pain in the ass to remove. It will most certainly involve making a custom tool in the moment (that’s what I did for mine). If you’re not super confident with mechanical work, leave it to a pro for sure. This is probably the least straightforward job on the e46, including and not limited to an engine rebuild or vincebar install. Word to the wise.

Fair enough, I didn't get that deep into it.