Play in wheel bearings or trailing arms?

[Phil_F_NM]

Recently I had a friend come into town and we took my '78 300D into the mountains for a day hike. Drove 9 miles up and 9 miles back on a bumpy dirt road and after returning from the day hike I noticed that the rear end felt a bit "loose."

Now, I checked the tightness of the rear wheel bearings when I first bought the car about 2 months ago then tried rocking each wheel back and forth after I changed my rear springs, shocks, subframe bushings and sway bar bushings. That work was done only 3 or 4 weeks ago and the car hasn't been driven very much since.

Shortly after replacing the suspension bushings (I DIDN'T get to the trailing arm bushings) I took the car to Firestone and got it aligned. I did the lifetime alignment since I know that after the suspension components really settle in, it's going to need another alignment anyway.

Now both rear wheels feel a tiny bit loose to me, like the bearings may need repacking and adjustment. I can rock both of the wheels back and forth a very small amount but just enough to make a slight thump. I had the rear end off the ground yesterday to replace my driveshaft carrier, bushing and flex joints and I tried quite a bit to rock the wheels and feel for loose bearings but they felt tight. Back on the ground, then the wheels are under a load, I can move them just a tiny bit. When driving there is no squealing, squeaking, grinding or any noise that I'd associate with bearings going bad. When off the ground, the only sound that the hubs make is from the brake pads dragging a very slight amount.

Could it be that all 4 bearings in the rear have come out of adjustment at the same time after a drive on a dirt road with some rocks and washboards? It seems statistically impossible to myself and a few friends but stranger things have happened, I guess.

Could it also be that the rear suspension settled in a bit more and my trailing arm bushings (which definitely need replacement) are causing this apparrent loose feeling?

I'm driving the car to Firestone tomorrow morning for a re-alignment. Problem is that the shop is about 60 miles away and if it's bearings, I don't want to drive that far and risk damaging my hubs more. I don't have the tool for the hub removal to adjust the bearings but after pay day I could swing purchasing one.

Thanks for any advice you all can offer.

Phil Forrest

[Stretch]

The rear wheel bearings aren't as simple as you might expect - have a look at these threads

PeachPartsWiki: Replacing the Rear Wheel Bearings

W123 rear wheel bearing removal help needed

If you have a dial gauge - DTI - clock gauge you can measure the bearing play. But to do that you should remove the axle...

[SD Blue]

Originally Posted by Phil_F_NM

........Could it also be that the rear suspension settled in a bit more and my trailing arm bushings (which definitely need replacement) are causing this apparrent loose feeling?..........................

Yes.

Failed trailing arm bushings can give the appearance of everything from front end problems to bad shocks. If they visibly appear bad, you will be shocked to find out how bad they actually are, once removed. Too much longer and you run the risk of damage to the trailing arm.

On the up side, you will also be amazed at the glue-like feeling while traveling wonderful winding roads, after they are replaced.

[Phil_F_NM]

I'm hoping it's trailing arm bushings, frankly. I have the bushings already and the tools necessary to replace them. I don't have the splined tool for the hubs plus it's a pretty big expense for my right now. Regardless, if they need adjustment, I'll buy the tool and adjust them.

Anyway, here she is:

[Diesel911]

Originally Posted by Phil_F_NM

I'm hoping it's trailing arm bushings, frankly. I have the bushings already and the tools necessary to replace them. I don't have the splined tool for the hubs plus it's a pretty big expense for my right now. Regardless, if they need adjustment, I'll buy the tool and adjust them.

Anyway, here she is:

You don't need the Rear Wheel Pin Wrench to change the Rear Trailing Arm Bushings.

There might be one in the Tool Rental program.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

Slide Hammering off the Hub or using a an old Brake Rotor reversed and beating on that to get the Rear Hub out (a new Hub is over $300) damages the Bearings.
Beating the Hub off from the inside outwards can collaspe the Metal on that end.

You won't really know what the Rear Hub end play is until you use a Dial Indcator to check it. Right now you only know when you rock the Wheel something seems loose.

[Phil_F_NM]

I don't have the tool for the wheel bearing castle nut so I can't do anything there until I get it.
I have to get the car all done and ready for a ~1500 mile trip up to the US Pacific NW just before Thanksgiving (I'm moving there.) Just under a month, so I'm hoping that it's a minimal of expense only. I just can't afford to pay anyone to do the wheel bearings if that's the issue. If I can do them, then I will.

Phil Forrest

[charmalu]

Great North West, Oregon or Washington. 3 Pick N Pull around Portland, one I know of in Vancouver. so there is a source of parts.

How many miles on your W123?.

I changed out my Sub Frame Bushings and Trailing Arm Bushings at around 360K miles. I also swapped in some used Trailing arms from a 85 300CD with less miles. think each side was around $42. Trail arms from a W126 81 - 85 are the same as the W123. I see lower milage 126`s than 123`s in the yards.

It would be easier to swap arms and pop in some new bushings.


Charlie

[Phil_F_NM]

My 300D has 287,334 miles as of the photo posted above. The odometer died when the car was owned by the previous owner and he said it may have had about 600 or so miles on it since then. he bought it to fix up and owned it less than a year, being forced to concentrate on other projects by external forces. I repaired the odometer the second week I owned it and added about 600 miles.

I'm headed to Vancouver, Washington; I just hope I can make it there. Troubleshooting this issue might be more difficult than the rest of the things I've tackled since I got the car.

Looking under the car at the trailing arm bushings, they appear very well cracked and maybe a bit shrunken but surely they look different than the brand new bushing that I have held in my hand for comparison. If they are almost as bad as the subframe bushings that I changed, then they are completely shot. Subframe bushings were cracked most of the way through and I pushed the center support portion out of the bushing with my thumbs.

Thanks for the advice, all! Keep it coming, I need all the help I can get!

Phil Forrest

[charmalu]

34 years is a long time, and the rubber does dry out and has been flexed a lot.
When i replace the one`s in the 85 300D, it sure tightened up the rear end. also replaced the Diff mount. and the rubber spacers for the springs.

That is a nice looking car you have.

Charlie

[Phil_F_NM]

When I replaced the springs in the rear and shocks all around, I also replaced the rubber spring spacers. I meant to replace the differential mount as well but ran out of time that weekend due to the stubbornness of the new subframe bushings THEN accurately lining the bushing up with the hole for that giant bolt. What a PITA.

I'm hoping that thetrailing arm bushings will be more forgiving. While I have those down, I'll do the differential mount as well and the rear end will be all tight and new. Well, at least the rubber parts will be...

Thanks for the praise on how she looks. There's a good amount of rust behind all 4 wheelwells. There's a nasty flap of rubber undercoating that people think is rust but it just hanging off the passenger side behind the front wheelwell, close to the jack-point. I just haven't bothered to cut it off. Some rust is through and through but only in small areas that I'll get welded up after I get to Washington. A few spots here and there which I need to scrub down to the metal and at least prime to protect the body. I have a lot of weatherstripping to take care of as well but she's coming together nicely.

Only 7 weeks ago there was a massive network of squirrel nest in the seats and other places in the car. No inhabitants but lots of evidence that the car had been home to some critters. The sunroof didn't work. Driver rear window was stuck 1/4 way down. Dash cracks were much worse. Seats were basically springs and vinyl. Carpet was wreck. Vacuum was completely hosed (pun intended.)

All that and a ton more has been fixed since I got the car. The best thing is that engine. It's smooth(as a diesel can be,) doesn't smoke even if I want it to, has no detectable blowby and can pull up a decent New Mexico grade over 50mph and accellerate, to boot.

I digress. back to my bushings v. bearings sloppiness.

Phil Forrest

[charmalu]

To do the Trailing Arm bushings, you are going to have to drop the whole Sub Frame to get the arms off.

Use 3 floor jacks, one under ea arm and one under the Diff. then lower the assy down and roll back out from under the car. Remove the 13mm bolt in the hub, the 2 24mm nuts and remove the bolts. then pull the arms off to replace the bushings.

some where in a thread I listed a detailed list what to remove before you lower it down. here is a good thread Army started.


Rear subframe removal and bushing replacement

Charlie

[Phil_F_NM]

Originally Posted by charmalu

To do the Trailing Arm bushings, you are going to have to drop the whole Sub Frame to get the arms off.

Charlie

Again? Damn!

Phil Forrest

[Phil_F_NM]

Got a call from Firestone this morning. They said the control arm bushings are completely shot on the right side and going on the left side.

Then the tech and I went back and forth as to the real definition of the control arms 'cause I was using the term trailing arms. We eventually came to the conclusion that we were talking about the same thing.. so I'll pick up the car in 2 hours, hit home depot for a foot of all thread or maybe a long grade 8 bolt plus some nuts, large washers and a plumbing fitting to press the bushings through the trailing arm holes and just a wee bit past into the pipe fitting.

I'll be doing this work this weekend and while I'm at it, I'll be changing the differential mount as well. Then next week the car goes to Firestone again for another alignment. Good thing I got that lifetime alignment on the car! I bet they secretly can't stand folks who use them as a diagnosis place only to go home and do the work themselves, then bring it back the following week for yet another alignment

[Stretch]

For each alignment they should use a spreader bar to set it to Mercedes specifications...