bmw 2002

Steering Coupler

Jun 29, 2014

     Hola, amigos. I know it's been a long time since I rapped at ya, but things have been kinda busy 'round here. In the two years (!) since I last posted, I've taken a new job, moved to a new state, and hauled the '02 (and all my other stuff) to two different houses. Hell, I started writing this post nearly a year ago. I've done a little work on the car here and there, and have a few posts coming down the pike: a replacement of the brake master and clutch slave cylinders to shore up the hydraulics, and a refresh of the fuel system to hopefully cure the engine's odd running.

     But first, here's a report on a genuinely quick-and-easy part swap: replacement of the steering coupler.

     So, the only reason I'm doing this project is because I'm currently in the middle of replacing the brake master cylinder, during which I had to remove the brake booster. With those parts out of the way, I've got great access to the steering coupler. Also, I bought a new urethane steering coupler from Ireland Engineering a long time ago. On a whim, I had added it to an unrelated purchase for a different project on account of how it was cheap, and, as has been proven many times, anything rubber on this car needs to be replaced. So, a brand new steering coupler has just been sitting in the parts pile for years, and now that the old one is staring me in the face, I took the opportunity to replace it.

     This turned out to be a pretty easy job; I think I got it done in a little over an hour. If you've ever got the master cylinder and brake booster pulled off the car, definitely consider replacing this part, if only preventively. It'd just be a pain in the ass to have to do it when the MC and booster aren't already off.

     A quick side note for emphasis: In addition to the 2002, I currently own a 1965 Lincoln Continental. It was having steering issues at low speeds, mostly when maneuvering its 5,000+ pounds around parking lots. I figured the power steering was failing, and since I've got no experience with power steering and no time to fix up TWO old cars, I sent it off to the shop. The shop guys (who dubbed the car "The Hotrod Lincoln") diagnosed the problem as a busted steering coupler—the very thing I'm replacing here. (They didn't call it a steering coupler, though—they called it a rag joint.) Anyway, all that is to say that replacing the Lincoln's steering coupler was a job almost identical to the one I'm showing below, except it was a pain in the ass because the brake booster and everything were still in the car and the Lincoln's design found all those parts tucked up against the firewall. This job won't be some quick afternoon swap-out if your car's fully intact. But if the coupler is cracked and broken, it could fix your borked steering like it did on my Lincoln.

The steering coupler on the 2002 has great access when the master cylinder and brake booster are removed. On the right is the square-shaped mount of the brake booster. With everything removed, the steering shaft, coupler, and box are well exposed. The rubber steering coupler actually appears to be in decent shape. This may be the only rubber on the car that isn't cracked.


The steering coupler has two pairs of nuts/bolts; two on the steering shaft's side and two for the steering box's input shaft. Here, I've removed the nuts. There's a braided metal strap that wraps around the rubber coupler, electrically connecting the steering shaft to the steering box, and thus the chassis. Turns out this is the ground for the horn button.


There are two connectors that have to be backed away from the coupler. I de-crudded them with a wire brush, loosened the bolts that hold them firm, then applied penetrating oil. Even then, they wouldn't just slide back. I placed the end of a crowbar up against the connector, then banged the crowbar's shaft with a hammer. That got them to back away from the coupler, as in this picture.


Both connectors have to be backed-off, then you can remove the old coupler and insert the new one. Reassembly is always easier than disassembly, and here's the new coupler installed and bolted back up. I cleaned off the grounding strap and reinstalled it, too.


There's way less flex in the coupler itself given that it's polyurethane rather than old rubber.


      I'm not convinced that a urethane coupler will actually translate into tighter steering. It certainly won't hurt. I can say that there's less bounciness when I pull on the wheel when the car's stationary; steering at low-speeds is a little more direct now. More than anything, it's a cheap part and an easy swap—provided you've got good access to the steering coupler. Consider doing it if you're overhauling the brake system.