I finished swapping an e36 rack into my airbag-equipped '90 325is a few days ago and have enough miles on it now to call it done. Most of the swap has been covered in previous posts - props to Ritalin Kid! - so I will add what I haven't seen before.
-I used the rack out of a 328. It's a 3.5 turn unit and had a "rebuilt by ZF" sticker on it so I think I lucked out and got a fresh one. I ditched the cooling loop because it won't fit on the e30. No worries, I don't think it's needed.
-I find the easiest way to pop the steering arm knuckle is to heat it with a propane torch for about a minute. It's not long enough to damage the tie rod boot but the heat expands the bore just enough to pop the tie rod out with a hammer.
-My e30 rack never felt that bad, but I could tell there was a lot of play in it when I got it out. I always thought that my play was in the u-joints, it wasn't.
-My spacers were lug nuts that I ground and filed down so that they were 10mm tall. Fit perfectly!
-I had an e36 high pressure line standing by, but I found it was much easier to make a small bend in the e30 line and it fit perfectly. Same with the return line, a few small adjustments and it fits great. I used new crush washers.
-I had to grind about 1/4 inch from the firewall towards the center of the car to clearance the steering shaft. The shaft moved about 7/8 inch.
-Much has been said about the plate that holds the rubber firewall boot in place. I decided NOT to fab a new plate because too much material would need to be removed from the firewall to really make it fit correctly and center the boot over the shaft. I think my solution works much better. I took some heavy rubber gasket material and sandwiched it between the plate and the firewall. It has a hole cut in the middle for the shaft to pass through and a slit to get it around the shaft. It seals the shaft nicely and is quiet.
My overall impression of the 3.5 rack is that it's a nice improvement, partially because of the quicker ratio and partly because it's tight. I have nice off-center feel on the freeway and the ratio is really noticeable in the parking lot.
I don't know how the myth got started that airbag e30's need to have the column changed. This was an easy swap. Dooo it! ;)
Hoveringuy
-I used the rack out of a 328. It's a 3.5 turn unit and had a "rebuilt by ZF" sticker on it so I think I lucked out and got a fresh one. I ditched the cooling loop because it won't fit on the e30. No worries, I don't think it's needed.
-I find the easiest way to pop the steering arm knuckle is to heat it with a propane torch for about a minute. It's not long enough to damage the tie rod boot but the heat expands the bore just enough to pop the tie rod out with a hammer.
-My e30 rack never felt that bad, but I could tell there was a lot of play in it when I got it out. I always thought that my play was in the u-joints, it wasn't.
-My spacers were lug nuts that I ground and filed down so that they were 10mm tall. Fit perfectly!
-I had an e36 high pressure line standing by, but I found it was much easier to make a small bend in the e30 line and it fit perfectly. Same with the return line, a few small adjustments and it fits great. I used new crush washers.
-I had to grind about 1/4 inch from the firewall towards the center of the car to clearance the steering shaft. The shaft moved about 7/8 inch.
-Much has been said about the plate that holds the rubber firewall boot in place. I decided NOT to fab a new plate because too much material would need to be removed from the firewall to really make it fit correctly and center the boot over the shaft. I think my solution works much better. I took some heavy rubber gasket material and sandwiched it between the plate and the firewall. It has a hole cut in the middle for the shaft to pass through and a slit to get it around the shaft. It seals the shaft nicely and is quiet.
My overall impression of the 3.5 rack is that it's a nice improvement, partially because of the quicker ratio and partly because it's tight. I have nice off-center feel on the freeway and the ratio is really noticeable in the parking lot.
I don't know how the myth got started that airbag e30's need to have the column changed. This was an easy swap. Dooo it! ;)
Hoveringuy