W123/W126 rear suspension arm...

zappa

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Hello all,

My W123 230ce isn't great right now, 29 years of having the wheels taken off and on, have taken it's toll, and the wheel bolt threads on the rear L/H hub are knackered.

I spent a day drilling out 3 bolts, and removing what was left of the bolts, though after re-tapping the suspect threads, and using new bolts, I was back to square one.

Not enough steel left in the threads.

Don't think I can get away with just 2 bolts holding the wheel on..

So I'm looking for a W123 (to '85) or W126 Series 1 (to '84) L/H rear suspension arm complete with hub, bearing etc..

Apparently they're the same part number.

Must be in fairly good condition please, i.e. not a block of rust, and with decent hub threads etc..

I've been informed that, it's easier to change the whole arm complete, rather than try to get another hub, stripping down, and rebuilding due to the special tools required to remove/install the wheel bearings.

Unless anyone out there has a better solution?

Thanks all for listening, hope someone can help.

Cheers!
 
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zappa

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Hello Malcom,

Thanks for the thread link, hopefully I won't get in to the same issue as aaz1978, though it's looking likely given the wheel bolt threads have started to go.

I've managed to buy a replacement arm assembly on Ebay just now, taking a gamble, but given the choice between new, and s.hand prices, I'll take a chance.

This problem has actually forced me in to doing the whole rear end bush replacement, I'd been planning for a while now.

Having done all the bushes on the front end last winter, I've not yet learned that laying under the car, during the winter, in a single garage,and no heating, is not quite how I would like to spend my weekends, but needs must.

The cars not a daily driver, so not in a rush

I'm aiming to remove the whole wishbone with arms to make life easier, any tips on this?

Apart from wishing me luck!
 

television

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I will see what I have though little on the 123 but there is the Haines book for what that is worth, the saloons is not interchangeable with the estate.


Yes plenty of good luck included.:D When you get to my age the urge to crawl under the car fades:(
 

ianrandom

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Yes I've heard the whole arm change is easier than the hub off. I may need to do this at some point.

The threads aren't great on one of my W126's either. Keep those air tools away from your older cars folk, hand torque only.. I guard mine carefully now..
 

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If there was enough room on the rear, I would have considered welding on some thin nuts on the inside of the hub. they would only need to be tacked on as the wheel bolt would be pulling it in tight.
 
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zappa

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Hello all,

the story so far...having received the whole arm/hub assembly, out of the box, its an aluminium arm.. which from some research won't be a straight swap, as its got the anti-squat mechanism, a different mounting position for the brake caliper, and the anti-roll bar is a different mounting and size.

After more research, it turns out the only special tool needed to swap the hubs, is the castelated nut socket, for the back of the hub.

Got one of these now, so...

The direction I'm going in now, is to swap the hubs over for the time being, the bearings on the 'new' hub are good enough for now, full subframe rebuild when it's warmer and drier!

I've relived the 'new' hub from the ali. arm, and hope to do the same to the original when time allows.

Swap them, put it back together, and torque it up with the help of a dial gauge.

In the mean time, I'm kicking a can around waiting for a new nut and crush washer, to complete the above.

Should get this sorted in the next couple of weeks, will let you know...hopefully smiling.
 

ianrandom

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Well done. Yes some of the rear arms are different as you say because of that anti squat thing.
I read this rear hub job is 8 hours or something in the shop.
 
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zappa

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Forwards at a glacial pace..

Thanks for the support Ian, at the rate I'm going, I reckon it'll take me 8 weeks!

Distractions of the work for a living type, keep getting in the way, bills to pay and all that.
I have managed to pull the hub off the car now, though what hurts about this saga, is that the original hub looks like new when compared to the replacement, which looks as if it got very hot at some stage in its life.

And the state of the hub nut on mine, looks like someone's been there before, am sure the factory don't smash them on with a chisel...

Which got me thinking when looking at the shiny original, am not an engineer but I know a good one, he'll probably laugh me out the shop, when I tell him my idea..if it works, I'll bore you all with the details.

Picked up the new grease seals, and hub nuts, bought two, just in case I want to do the other side, or have no choice later..

While there, I got quotes for genuine wheel bearing kits, and a new hub, just to give me the motivation to find a way around my troubles...kits are £185, hub £460, both plus VAT of course..nice, Febi for bearings it is then.

Till the next thrilling instalment of positive mechanics!...
 

ianrandom

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Ah thats a lot of money, but the quality will be great. Having said that I have no idea how Febi quality comes out with bearings and stuff.
 

syncropaddy

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I think Im right in saying that an aluminium are is off an SEL 126. Yes / no?
 

ianrandom

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Dont think so Andrew, I *think* within certain years they can be on any of the 126 cars that had the anti squat from what I can tell.
 
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zappa

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Hub sorted...

Finally done, back on the road..
I decided to fit the donor hub off the aluminium arm for the time being, as the bearings seem fine for now, and the planned rear end bush/bearing replacement will be done later in the year.
The original hub I had modified by the engineer, will now sit in a box until this happens, and the other hubs are done likewise.
The modification I had in mind originally, was going to be to have a new set of holes drilled and threaded, in between the original ones, which was feasible but, not ideal.
Then I spoke to someone smart, used to doing serious mods to Mercs, and simple when you know what your doing.
"The standard wheel hub bolts are M12 diameter, why don't you just go up a size to M14 bolts from a Vito, the clearance is there, the disc mounting hole sizes are correct, and all you got to do then is shorten the bolts, and ream the wheel mounting holes out a bit, it works, I've done it.."
Thanks Martyn!
I must add that the wheels intended for this project are not going to be my standard Fuch alloys, with the steel inserts, as these won't work with this mod.
But as I now intend on going for a set of genuine 15" ATS Bundt/Barock replicas, it will work.
Anybody got a set of these for sale? Preferably straight, and no filler in the rims.
 

ianrandom

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Oh, great idea actually. Thanks for the tip!

You can buy the bolts in any length anyway from a good shop. I use Speedshack in West Drayton, just because I had problems and they sorted me out very quickly and easily.
 


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