upper trailing arm W124

[SilverSaloon]

hi

my W124 estate has failed its MOT on "rear upper trailing arm has excessive play in a pin/bush"

is a trailing arm and a control arm one in the same?

can anyone show me a diagram of the actual part? i've yet to have a look and assume its one of the arms that come across just needs a new bush but if anyone can pin point it on a diagram that would be useful.

thanks

Derek

 

[grober]

By your description its part 80 in the diagram but its the bushes on part 56 that usually go?

 

[SilverSaloon]

By your description its part 80 in the diagram but its the bushes on part 56 that usually go?

Thanks grober - thats perfect.

Next question - how easy is it to remove these parts? i have a donor car sitting in my garage I hope to swap the bits over to save waiting on parts arriving as i need the car back on the road ASAP. Is there anything specific i need to do prior to unbolting them? can i just take up the load of the suspension on the hub and then remove?

i'm going to have to do this work on my driveway as the alfa is dead in my garage along with the donor 124 so weighing up whetehr to do this myself or get the MOT station to replace it... it depens on how quick and hard it is to do!

cheers

derek

 

[renault12ts]

Thanks grober - thats perfect.

Next question - how easy is it to remove these parts? i have a donor car sitting in my garage I hope to swap the bits over to save waiting on parts arriving as i need the car back on the road ASAP. Is there anything specific i need to do prior to unbolting them? can i just take up the load of the suspension on the hub and then remove?

i'm going to have to do this work on my driveway as the alfa is dead in my garage along with the donor 124 so weighing up whetehr to do this myself or get the MOT station to replace it... it depens on how quick and hard it is to do!

cheers

derek

It's easy...I did it myself for the same reason. The new part is cheap BTW, on Ebay.

 

[SilverSaloon]

It's easy...I did it myself for the same reason. The new part is cheap BTW, on Ebay.

Yes normally i would just order up a new part - but ideally i'd like to fix the car tommorow (sunday), get it retested monday morning and then drive it to work.....

if i wait for the parts its going to be next weekend until i get the time to do the job....

 

[SilverSaloon]

so can i remove part 56 completely easily? do i need to just put a jack on the hub before removal or can i just undo without doing this???

cheers!

derek

 

[renault12ts]

Just undo. But be careful, we are talking part 80, not 56.

 

[grober]

Sorry just back--- part 80 [ the pulling strut] is a straight swap as has been said part 80 should come complete with bushes. If its part 56 [the camber strut] its slightly more complicated as this the arm with an eccentric bush+ contour washer [at the hub end I think ] in it to set the rear camber. All you can do is take some careful measurements and mark the position of the camber washer before undoing anything. Make sure you put the bolt back the same way with the contour disc behind the bolt head and the washer behind the nut. Before final tightening up of the securing bolts [ for 80 or 56]make sure the drive shaft is horizontal or in the normal driving position either by jacking up the hub or by tightening with the car resting on its wheels. Do one side at a time and use the untouched one to confirm the orientation of components on the one you are working on.
ps part 80 used to be adjustable like part 56 but was fixed in later models iirc

torque settings IRRC but don' t take as gospel

70Nm inner [subframe ] 40Nm outer [hub]

 

[kth286]

the two struts that are subject to most force and wear first, are the torque and thrust struts (80 and 119)

The camber strut is not much affected (non adjustable by the way)

That leaves the tie bar (104) which is adjustable for toe alighnment, and the bolt can seize, causing rear tyre wear.

I would have thought if wear was that obvious on the MOT, you will find it, when you jack up the car and put a jack under lower arm to take the tension off the struts.

Of course, you should not count on the used replacement to be any better and may be a waste of your time - better to get new.

 

[SilverSaloon]

ok, i've now had the chance to take a look at this and the only serious play (and its quite bad actually) is the lower arm.

how hard is this job DIY? i'd have to replace the bush highlighted

thanks

derek

 

[balge]

Hi
I get confused with car suspension but is this link relevant? R&R rear carrier spring link bushings with Baum Tool - Benzworld.org - Mercedes-Benz Discussion Forum

cheers!

 

[grober]

That's called the spring support arm. Problem is you will have to take the tension off the road spring to remove the arm. When changing REAR SPRINGS the recommended way to do this without the proper spring compressor is to remove the inner single [subframe ] bolt and lower the arm on a jack when the spring will fall out.

To renew the outer bush on the hub end ---- I hesitate to say its adjustable maybe kth286 could comment? [ offset bush/washers etc] since my experience is on the 190 models but check and mark any washer positions before dismantling. You will again have to release the spring tension and then undo the roll bar drop link bolt and the bottom shock absorber bolt and finally the outer bush bolt [ depending on clearance you might need to remove the rear caliper to get access] AFAIK the bush is now removed and replaced.
Personally without the proper spring tool I would be inclined to drop the spring support inner end first to release the spring tension [ safer] and then work on the outer end. You could simply drop the outer end but I feel you have
1:- less control
and
2:- the spring closer to you

It's a personal choice- best of course is with the correct spring compressor.

Again final tightening of all bolts should be done with the spring back on and the car resting on it's wheels.
.

 

[renault12ts]

Go back to your OP. It's the upper trailing arm (80) which you must replace for the MOT, the other part can wait.

 

[SilverSaloon]

Go back to your OP. It's the upper trailing arm (80) which you must replace for the MOT, the other part can wait.

there isnt any play (as far as i can tell) on any upper arms. the bottom one however wobbles around like its got no rubber bush left at all. Essential to replace.

it sounds like its too hard for me at the moment to do as i need to get it fixed ASAP so i'll hand over whatever needs doing this time to the garage.. i've heard too many horror stories re W124 springs!!!

cheers for the advice

thanks

derek

 

[renault12ts]

The outer joint on no.80 can slide along the bolt...check that.

 

[kth286]

that bush you refer to is a muti-directional special bush (about £30 last time)

it needs a special tool to change it.

it takes like 20 minutes with tool - without tool, could hours.

find garage with tool and is familiar with job.