Any pointers before swapping 85 300TD low. control arms with hubs? - perhaps damaged? - PeachParts Mercedes-Benz Forum

azitizz · #1 08-26-2011, 12:07 PM

My rear bearings are finished the left side especially as its been smoking lately and some serious grinding and sometimes squealing noise coming from it. I've been procrastinating dong much about it but at this point I dont feel I have much choice. I went out and got two "new" Lower control arms with the hubs attached for $250. They are full of oil which i guess is good for rust. but I would like to refurbish them as much as possible while I have them off.

I thought to clean them I would simply soak them in a large tub with diluted degreaser overnight but I wondered if this could leak in to the bearing casing and pose a risk to the bearings. Also would there be anything wrong with submersing the whole brake drum?

What do these look like to you? I also had a concern with some metal damage to the "new" hub. in the pictures I tried to capture the dents made to the edge of the inner hub, I guess where the axle goes? Do these dent marks look serious to anyone or are they no big deal. It looks like it was perhaps from the removal of the axle?

What would anyone suggest as a some importnt steps to take before installing these?
Thanks

andrewjtx · #2 08-26-2011, 12:26 PM

You're saying LCA but you mean to say Rear Semi-Trailing Arm.

The inside flange of those hubs look horrible. The seal on the inside looks toast as well. I wouldn't trust the bearing in those arms for anything...

I would suggest you find better donors. I'm not sure how salvageable those hubs are, but the arms should be fine. Better donor hubs, new bearing & seals, all new e-brake hardware...

charmalu · #3 08-26-2011, 01:06 PM

The bearings are replaceable, here is a DIY.
http://www.peachparts.com/Wikka/W123RearWheelBearings

Those bearings don`t look good. I pulled both Trailing Arms off a 85 300CD in PNP last year for the up grade on our 85 300D. I paid $42 for ea arm with the hubs. maybe $250 was for shipping and the parts.

Either replace the bearings or find some lower milage arms. the W126 first generation (81-85) will also fit the W123.

Pressure wash the arms at one of those 25¢ DIY car washes. mine had that Cosmoline waxy stuff on them and I wiped them down with paint thinner (Mineral Spirits). I use POR products, so used the Marine Clean for a final degreasing, sanded and applied 2 coats of the POR paint.

since you are this deep into the project, good time to replace the trailing Arm bushing and Sub frame bushings, and Diff mount.

If the car is a rusted old beater, may not want to do the additional work.

Charlie

Stretch · #4 08-26-2011, 01:12 PM

I kind of go along with what andrewjtx is saying - it is really difficult to really know how good the condition is inside the hubs. From the outside it looks like whoever changed the bearings didn't use a puller - they were hammered out. I personally would not have reused a part after knackering it like that - but it doesn't necessarily mean that the bearings inside are shot.

You can however check the end float (play) by setting up a dial test indicator (DTI) / clock gauge... when installing these bearings you are meant to tighten the lock nut until you reach 0.04-0.06 mm

http://www.peachparts.com/Wikka/W123RearWheelBearings

My advice would be to measure the clearance before making your mind up about the condition of the bearings. You also need to consider other things such as smoothness of running / weird noises etc etc... be very critical of this as it will probably be 100% worse when you fit it to the car.

As for the condition of the trailing arms - what is that line on the trailing arm sitting on top?

If that is a crack or a bit of plate work welded on top - junk it.

As for overall condition - go for gold with an angle grinder and a wire brush attachment. Give it some stick. If you make holes - junk them. It is much better to make holes and find problems with them now.

After you've cleaned them up put on something like POR15 to protect (at least 2 coats) and then top coat with their chassis black for a really good job.

azitizz · #5 08-26-2011, 02:56 PM

The line I believe you are referring to is simply a spot of the grime scraped off during transport. To me the plate looks like its something original to the arm. Although I do feel a little ripped off with these but I have few options.

Im no longer near the US border so shipping parts within the US and picking them accross the border up is not an easy option for me now. I think these parts can sell for so much more here as they are not as common.

Very few parts stores here rent out tools or do little tests for certain parts either. with only 30million people here in the great white north, we don't have all the goods and services around the corner like in many populated states. Or cheap shipping either...

Getting the dial gauge and the special Mercedes tool to change the bearings is not easy for me to obtain.

They feel smooth to turn by hand, and certainly they must be better than my squeeling smoking, grinding hub, Its a bit comforting to think perhaps the bearings have been changed more recently than the ones in my car. The body is in pretty good shape still on my car and unfortunately the trailing arms look like they are in a little better shape than the ones i bought.

What to do. I need a working car asap? The brearing change looks well documented with DIYs but also needs difficult to get tools for me and lots of time it seems. If there are any Canadians reading the forum who have tools to rent and send please let me know!
Thanks!

Diesel911 · #6 08-26-2011, 08:50 PM

Actually it does not look like someone improperly knocked out the Hub. It look either the Arm was thrown against something or something was thrown against it at the Junk Yard.

If it was Me I would check the Hub End Play. If it is OK I would clean the Arms and change the Rubber Bushings.
After that I would install the Arms and drive with them and see what happens.
I have had a Junk Yard Trailing Arm; installed as is on my Car for almost 4 years not with no issues.

If it turns out the Bearings are no good or if later the Bearings go bad it is actually easier to beat the Rear Wheel Hub out using a Slide Hammer or an Old Brake Rotor and a Hammer with it on the Car.

Once I found out a new Hub was $300+ I decided to salvage the Rear Hub from the cracked Arm that I had Pulled off. I used the Old Brake Rotor and Hammer Method with the Arm laying on the ground trying to brace it against something.
It was clear that had the Arm been still on the Car my Hammer Blows would have been more effective.
I also think when it comes time to tighten down the Hub Nut that that will be easier with the Arm on the Car.
Also note that beating off the Hub damages both inner and outer Bearings.

Stretch · #7 08-27-2011, 03:31 AM

Quote:

Originally Posted by azitizz

...
Getting the dial gauge and the special Mercedes tool to change the bearings is not easy for me to obtain.

...

Getting hold of a dial gauge shouldn't be that much more expensive in Canada than say Europe. I didn't buy professional measuring equipment calibrated by NASA...

...as for the MB tool I would recommend that you fork out the big bucks for the special tool available from the dealer. I get the impression (from what I've read here on PP) that the non MB special tool requires some modification prior to use - to my mind even if it is a 1/4 of the price that means it is wasted money. I spent the 120 euros for the MB tool and it slotted straight in there like a gigolo at a nymphomaniac self help group. You could always offer your MB tool for hire to other Canadian members...

vstech · #8 08-27-2011, 10:27 AM

that nut damage around the bearing looks like the axle retainer bolt came out, and the axle was wobbling around prior to them junking the car. the dents are same diameter and spacing as the axle splines...
notice how the inner splines on the bearing closest to the damaged outer part are gouged a bit...
I'd be worried using those on my car.

Stretch · #9 08-27-2011, 01:46 PM

Quote:

Originally Posted by vstech

that nut damage around the bearing looks like the axle retainer bolt came out, and the axle was wobbling around prior to them junking the car. the dents are same diameter and spacing as the axle splines...
notice how the inner splines on the bearing closest to the damaged outer part are gouged a bit...
I'd be worried using those on my car.

Wow I didn't think of that - azitizz take a photo looking down into the recess for the axle shaft so we can confirm..

...the existing pictures are a bit fuzzy...

azitizz · #10 09-15-2011, 10:30 AM

Sorry I never followed through with this route so I never replied to the . I took them back but now I seem to have lost $250 in the process. the shop owner says he will only credit me for other parts... I decided to go through with the bearing change myself as he only seems to have junk pieces that are in as bad or worse shape than whats on my car.

What do some of you think about these shots of the rear hub/axle. Its in a pretty serious state now as Its become so hot Ive been smelling burning rubber or something. Ive quit driving it altogether and now my rear brakes are out. It seems all the fluid has drained out of the reservoir for the rear brakes.

It looks like there's a space in the hub that shouldnt be there, and the sway bar link has been detached for some time Im assuming. By the pictures what are your thoughts. Im wondering if theres axle damage?

What is the function of the sway bar stabilizer plastic link?