1987 300D front lower control arm servicing - PeachParts Mercedes-Benz Forum

sixto · #1 02-26-2014, 07:35 PM

I took the '87 300D for a wheel alignment after getting new tires. The alignment tech showed me play in the driver side control arm forward bushing and ball joint. I'd been hearing a clunk when hitting a driveway right front wheel first and intermittent vibration when applying the brake at speed such as slowing from 64 to 45 for a freeway junction. I can lift my foot an reapply the brake and there'd be no more vibration. Mind you, at that point I'd have to get on the brake harder since I'd be closer to the turn. He set a pry bar between the wheel end of the control arm and bottom of the knuckle to show axial play. Moving the unloaded wheel up and down as you would on other cars won't reveal a worn ball joint. I removed the LCAs to replace the bushings and ball joints. Sadly, my early build car has the @#$%&! W201 style single piece aft bushings. This car was in Dallas for 20 years and San Jose the rest of the time so there's no rust and fasteners aren't seized. Weeping turbo and front crank oil seals make sure of that

It took very little coaxing to remove the split type forward bushings. The aft bushings are a different story which is still being written. To this point I ruined the passenger side LCA and the aft bushing is still in place. I set a bottle jack between the forward and aft bores to press out the bushing but that just deformed the LCA. The bore flanges are torn up form various drifts and cups. Sigh... Here's some pics for posterity:

LCAs side-by-side -

LCA aft bores, passenger side (center section torn off and removed) is bent -

My early build '87 300D has the Option C W201 style aft bushing -

My version of this tool (threaded rod, 2" pipe, S&K 36mm socket drift) didn't work -

Driver side ball joint showing small tear on boot -

Passenger side ball joint showing clean intact boot -

Passenger side boot removed to show no lubrication -

Here's a video showing the ball joint that pivots tightly but has about 3mm of axial play:

20140226_133616_zpsade9d9fa.mp4 Video by tabijan | Photobucket

Sixto
87 300D

300GD · #2 02-26-2014, 10:03 PM

Nice write-up. Do you know either a build date or chassis serial number which would have been the cutoff for those 201-style aft bushings in the LCA?

Maxbumpo · #3 02-27-2014, 04:37 PM

Having recently been down this path on my '95 sedan, I would heartily recommend you purchase new lower control arms from MB. These come with new ball joints and new inner bushings installed, and will save you a LOT of labor time. I think they can be had for about $300 each? The cost is rather up there, but I will never do this job again (replace ball joints and replace bushings), I'll get new lower control arms. I really Really REALLY don't like suspension work!

Background: My sedan lived in NY for too long, so it has some rust on exposed things like suspension components. I had to use a saw-z-all to cut the eccentric bolts on the lower control arm inner bushings, and then get pretty mid-evil with torch and pullers and grinder to get all the bushings out and the rust cleaned up.