Steering rack identification?

[Ian]

Can someone help me ID this steering rack?  I thought it was for a 320i, which I was considering transplanting into my 2002, but none of the part #'s stamped into the case come up at realoem.  Here is a comparison of my mystery rack next to a 323 rack.  The stamping in the casing says BMW 76/77.

Edited August 8, 2020 by Ian

[albatcha]

Didn't find any official info, but this ebay seller

 

https://www.ebay.com/itm/77-BMW-E21-320i-Rack-Pinion-Steering-Gear-32111116908-32111114994-E21362-/114256456769?_trksid=p2349526.m4383.l4275.c4#viTabs_0

 

says his rack with the same part number was pulled from a 77 320i.

[albatcha]

Does this website have the correct info? Who knows

 

http://partinfo.org/bmw-32111115346/

 

"Steering Gear
Lath without G/U BMW 3 E-21 1975-1984"

 

What is Lath without G/U? Also who knows, not me.

[TobyB]

I don't remember the 4 cylinder 320 ever having power steering.

 

Did the 6 cylinder, maybe?

 

It reminded me of the E30 rack, in its details, but that doesn't mean too much,

as BMW shares design details all over.   Plus your date CASTING rules that out.

 

And 5ers and 7fers had steering boxes into the 90's....

 

hmm.

 

t

 

[Ian]

Right, the power steering rack is from the 6 cylinder 323.  I'm flumoxed with the manual rack.

[MOESPEED2002]

Ian,

 

Yes. That is a manual rack from a E21. I have the same rack in my M2 stamped 79/80.

 

Moe

[MOESPEED2002]

Ian,

 

Also, if your undergoing the r&p swap. Here's some information of what I have done, gone through, changed, and resulted from my progress from the swap.

 

Here is also some information relating to steering arms.

 

02 - 180mm w/14 degrees ack

E21 - 130mm 

1st set M2 - 140mm w/21 ack

2nd set M2 - 140mm w/14 ack

 

I have not driven the car with the new 140mm arms w/ 14' ackerman. I have tracked the car with both 02 steering arms and my original set of 140mm arms that had 21' ackerman. The 02 arms were good but slow and lazy to steer. The 140mm/21' arms understeered but were quicker.

 

Amazing how little room is in a 15" rim with BBK, bumpsteer spacers, and tierods on short steering arms. If you can find room, I'd recommend reducing the ackerman more.

 

Hope this helps, any questions PM. 

 

Moe

Edited August 9, 2020 by MOESPEED2002

[Ian]

Hi Moe,

Thanks for all the good info!  Narrow rear-steer racks are hard to find, and I will most likely have to get a custom rack made. I want to use the 320 rack as a model to get the tie rod geometry correct.  Unisteer is one possibility, as are the only manufacturer I have found that have an option for the pinion angle to be 90 degrees, which will make it easier to connect to the steering column.  

 

From talking with rack manufacturers I want the inner articulation point to be inline with the inner control arm bushing in the '02 subframe, and have the tie rod parallel the control arm, to minimize bump steer.  I'm going to make a temporary bracket to mount the 320 rack on my subframe and measure bump steer to confirm. I have also been told that our steering arms are too long for rack&pinion, as they were made long to help with manual steering box effort but slow down a rack, so will look into shortening them as you have.  I've got software somewhere that should help with the theoretical aspect of Ackerman and bump, but that is so dependent on accurate measurements that I'm hesitant to put too much faith in the software, and will likely rely on trial-and-error.

Ian

[MOESPEED2002]

Ian,

 

R&D is all I have been able to rely on myself, but you can skip some of my beginning efforts and pickup from where I left off. I didn't realize the complexity of undertaking such a task. Throwing in a rack is for the most part is straight forward.......take some measurements, center stuff, fab stuff, weld in stuff, cut to fit stuff, bolt on stuff, but that is where is ends. You will just get a car that steers again, but really doesn't perform for what were expecting on a track.

 

If you got a software program that would be the ticket to shaving time off the r&d side of things and get a farther head start than where I am at to completing and finalizing a build. Being able to input numbers and spit out results without spending a penny on materials and valuable time on a guess is worth every cent. So far all that I have done has been positive towards making progress. Large part of the equation regarding bumpsteer will come from arm geometry not so much steering geometry, which Lee's kit fixes. If you don't use them all ready, you should, It helps any lowered 02. I think BMW got the 02 suspension geometry right from the start and is a good setup to build of off.

 

Placement of the rack onto the subframe in relation to your steering arms is where that is most critical. Whether you have a custom narrow rack from Unisteer or an oem E21 rack. You can change ackerman by simply moving the rack forward or rearward. Shaping steering arms so that your pivots work in conjunction with suspension arms are important too, but I think its second to the design due to rim offset and caster.

 

What I have found from the beginning is that the rack needs to be placed as far forward as possible to the subframe. I even flipped my arm hardware around so the nut was forward to get that extra 1/4" inch. Lee's kit moves all the pivot points down near the bottom of the rim so finding room is difficult. That is why I made my first arms with more ackerman to get away from the tierod rubbing the tires. I was able to build my second set 16mm out to decrease my ackerman steering angle back to the 02 geometry, but it's tight.

 

Sorry for long winded post and thread jacking. R&P is a commitment but looks like your pretty committed at this far in your build, so what do you got to lose.

 

Moe

 

 

[Ian]

Hey, no problems with informative posts, this is great!  I do like to tinker, so will probably go ahead with this.  

I agree with you about Lee's roll center spacers, they are really helpful.  I have his 22mm drop with the offset for more camber, and I set up one side with and one side without for comparison. The spacers noticeably dropped the lower control arm back towards parallel with a lowered car.

[Tommy]

You have your basics right -  Good luck!

Hate to watch someone just throw in a rack picked from backyard without any understanding, then call it an upgrade.