My 300D started making some funny scraping and grinding noises from the back, and I've come to the conclusion that my left rear wheel bearings are shot. I found this procedure for replacing the bearings PeachPartsWiki: Replacing the Rear Wheel Bearings

From reading the procedure (much more informative than the FSM), I know I will need to buy several tools to do the job myself, including the special socket for the bearing nut, a brass drift, and a three jaw puller. I think the combined cost of parts, tools, and materials is going to run me about $200, and the work should take me about three hours including reading and re-reading the procedure, tea breaks, etc.

I will make some calls Monday for estimates from some shops to see what they would charge for the same job. I am leaning toward doing it myself unless someone quotes me $300 or less.

One of my concerns is that if the left side bearings are toast, the right side probably isn't far behind. Is this right, or does one side routinely outlast the other by a large margin?

Any advice or comments would be appreciated.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

I too followed the advice in the wiki when I did mine.

I really struggled to remove that slotted nut.

In my case I reckon the special tool would have broken (on both of the trailing arms that I had) if I had tried to use them to remove the nuts.

Here's what happened to me! =>

W123 rear wheel bearing removal help needed

If you look on page two I show an alternative way of getting those pesky nuts out. You can't do this for installation though - you do need the special socket for installation.

Some people say that the cheapo special tools don't fit the nuts and that you need to file bits off of them. I bought the dealer one - it cost me about 120 euros but it slides on in there like it was made for the job. If you have the time the alternative is to buy a large socket and grind out your own special tool - if you have the time, energy and willingness...


In the wiki it says to use a (copper?) punch to hammer out the hub. Don't do this - you are most likely to damage the hub. I reckon you are much better off trying to rig up a puller. If you look back in that thread I posted I show something I rigged up with wood and threaded bar. It isn't pretty but it does work - but please note I removed the trailing arm for other reasons and was therefore working on a bench: Not on a car.


One other thing that I think I should point out - you need to apply great amounts of torque to remove these nuts and to tighten them up. You need a decent grolly bar - something longer than 40cm depending on your body weight!!!!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I find it much easier to pull good trailing arms from a parts yard, and swap the entire thing, rather than go through the issues of rebuilding the rear bearings...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Please define a "good trailing arm" from the perspective of the bearing, when viewing the trailing arm from the outside at a parts yard...............????

In simpler terms, how can you tell the condition of the bearing on a trailing arm that is rusting away in a salvage yard?

You will need the special socket to remove and install the nut. A simple slide hammer with fingers for the lug bolts will remove the axle. Don't even think about hammering on the threaded end of the axle.

Also, if the collapsible spacer is not damaged, refit new bearings with the old spacer and check end play while they're dry. If it's too small, you'll have to collapse a new spacer. If it's too large, you can re-use the old spacer, just collapsing it a little more. If it's in spec., re-use the old spacer and save yourself a lot of work. That may be the case, as bearings are made to a standard dimension.

I've been flamed for this before, but a spacer is a spacer, it doesn't matter if it was collapsed to its dimension a day ago or 30 years ago when the car was made.

__________________
'83 300D, 126K miles.

It`s getting harder to find low milage MB`s in the yards today. I did replace my rear Trailing Arms from a lower milage 85 CD that was totaled. Not saying this is the best way to go, and that the bearings will not give me troube down the road. but has worked good for several years.

I kept the old arms and have another set. I paid $42 each plus tax.

Around here the cars don`t stay in the yards long enough to rust away.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Is it time to get some new bearings in the old ones then Charlie? You know how it goes - bearings only "go" when it is least convenient.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Don`t put a "Hex" on me now.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Sorry - didn't mean it that way - the year of the dragon is gone - we should all be OK now!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I would not advise using the Brass Punch to drive out the Hub from the Housing as the lip that the threads are on is very thin and easy to spread out. A new Hub was $350 each a few years ago.

Reversing an old Brake Rotor and beating the Hub out is safer for the Hub.

Did I mess seeing a Dial Indicator and Magnetic Base on your List; to adjust the bearing Clearance/End Play.

I cracked My rear Trailing Arm and replace it with a used one with no issues for over 4 years now. It got Me on the road fast also.

I don't know what a pull it yourself Junk Yard sells them for but deliverd to My House it one Trailing Arm was $149 over four years ago. I am guessing it would be 1/2 that or even less if you Pulled it off yourself.

On the Cracked Arm I used a Brake Rotor to beat out the old Hub to keep that part for later.

I suggest that you use a new Crush Spacer because they are realatively cheap and if you are careful not to over tighten it the first time you will be done with the Job.

__________________
84 300D, 82 Volvo 244Gl Diesel

You would be limited to bringing your Magnetic Base and Dial Indicator with you and you can visually inspect the Arm for rust Holes and cracks. And, of course rotating the Hub to see if there is any roughness when you turn it.

You also have a choice to buy the Warranty/Insurance on the Part.

I bought 2 used Trailing Arms and used only one on the Car over 4 years ago and it has been fine.

If the used Arm turns out also to have bad Bearings it is still not a tool loss due to the Cost of a new Hub.
If you can get the Hub off safely there is going to be somebody who needs it eventually because a lot of People are going to try to beat out their original Hub and ruin the threaded end.

To a lesser extent the Arm without a Hub could also be sold.

Also when I got My 2 Arms they came with the Parking Brake Cable and Parking Brake Shoes.

__________________
84 300D, 82 Volvo 244Gl Diesel

I already have those.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

Is this the fundamental difficulty...........the inability to get the hub out of the trailing arm without damaging it beyond repair?

In the last 3 years I have read of at least 2 people damaging the end of the Hub and needing a new or used one; so it does happen.
It is also possible for one of the Bearings go spin on the Hub and damage it.

If I had the rear Wheel Bearing Go bad in My first year of Mercedes ownership and I had decided to change them I would likely have used a Punch to try to beat out the Hub and that not only would have made it harder it would likely have damaged the Hub.
Since that time I have learned a lot on the various Mercedes forum and know where to look up info and have aquired the Tools to do this job.

In My case the Arm was cracked, previous to being cracked it had rusted trough holes in it. So in My case changing the whole arm was a good deal.

It is true that buying something at a Junk Yard you are taking a chance with pretty much any Part that has parts in it that move and can wear.

Any way it is nice for the Original Poster to have some options to pick from.

__________________
84 300D, 82 Volvo 244Gl Diesel

Well, that was my original concern. The OP needs to change bearings on trailing arms with 250K on them and the recommendation is to get one from salvage with potentially the same miles.

Odds are that he's going to have to do bearings on them in short order anyway, so I don't see the benefit other than the cost and risk of the work.