How hard to fit poly bushes on upper control arm inner mount

[UKDaveJ]

I bought some polyurethane bushes some time ago, but never got around to doing the work on my 1984 635csi.

My shudder under braking has got much worse over time & having replaced a failed wheel bearing yesterday, the worn bushes are more evident.

I can see how to undo the inner bush mounting bolt, but don't know whether the old bush should just push out with little force, or whether it needs significant force, with something like a puller?
Will the new ones just push in or need to be pressed in?

Anyone who has done this job please pass on your knowledge.

I guess usually, the whole arm would be replaced if the bush has/had failed.

Look forward to hearing from you.

Dave

[KC Ron Carter]

I have changed the bushings by using a hack saw blade to cut the band on the old and used a BFH to beat the new bushing in with an assortment of drifts.

BFH, is a big FLUTTED hammer.

I have also had to use a 40 ton press to insert one.

The sizing changes and the required force also.

I would try at home but be prepared to use an outside shop to push it in.

Do not start on Sunday afternoon and plan on driving on Monday morning.

Later,

[KC Ron Carter]

I have changed the bushings by using a hack saw blade to cut the band on the old and used a BFH to beat the new bushing in with an assortment of drifts.

BFH, is a big FLUTTED hammer.

I have also had to use a 40 ton press to insert one.

The sizing changes and the required force also.

I would try at home but be prepared to use an outside shop to push it in.

Do not start on Sunday afternoon and plan on driving on Monday morning.

Later,

[UKDaveJ]

Thanks Ron.

I decided not to have a go today, I don't use the car every day anyway, but this smacked of one of those jobs that looks straightforward, but could also be an absolute bugger!

I'll jack the car up in my single garage in the week, take the whole arms off one at a time (can't get to both sides very easily at the same time) & take them into work, our neighbouring company have so decent presses, so fingers cross we can pop the old ones out & new ones in.

I also need to check the ball-joints at the strut end, if they are also knackered then I'll change the arms complete for new ones & probably buy a second pair & fit the poly bushes in them. That way I can always change back if I find the poly ones are just too firm/sensitive etc.

Dave

[Erwin8r]

Dave, so how did it go?

Thanks Ron.

I decided not to have a go today, I don't use the car every day anyway, but this smacked of one of those jobs that looks straightforward, but could also be an absolute bugger!

I'll jack the car up in my single garage in the week, take the whole arms off one at a time (can't get to both sides very easily at the same time) & take them into work, our neighbouring company have so decent presses, so fingers cross we can pop the old ones out & new ones in.

I also need to check the ball-joints at the strut end, if they are also knackered then I'll change the arms complete for new ones & probably buy a second pair & fit the poly bushes in them. That way I can always change back if I find the poly ones are just too firm/sensitive etc.

Dave

[UKDaveJ]

Dave, so how did it go?

Sorry to disappoint, havn't had a chance to get the arms off yet. Guess will have to do this weekend instead.

Am not sure about something. If I jack my car up on the drive, remove the arms, can I safely & gently put the car back in my garage until I'm in a position to put the arms back on? I realise the arm is linked to the strut, but not sure whether just moving the car & steering wheel over a few feet of driveway will cause me any problems - or more importantly, the car..?

[Erwin8r]

It might be possible, but I wouldn't do it. I would try to jack it up in sitio and leave it until I replaced the arms...

-Erwin

Dave, so how did it go?

Sorry to disappoint, havn't had a chance to get the arms off yet. Guess will have to do this weekend instead.

Am not sure about something. If I jack my car up on the drive, remove the arms, can I safely & gently put the car back in my garage until I'm in a position to put the arms back on? I realise the arm is linked to the strut, but not sure whether just moving the car & steering wheel over a few feet of driveway will cause me any problems - or more importantly, the car..?

[UKDaveJ]

Thanks Erwin, you've confirmed my feeling of trepidation!
Will report when I've done it & can feel the difference, the brake 'shimmer' has been starting to drive me nuts, especially since changing my failed o/s/f wheel bearing - everything is now so smooth, the shimmer feels much much worse!
Dave

[UKDaveJ]

I decided against using the poly bushes in the end. They're bought, so I can always fit them in the future. The thing that swayed my decision was the ball-joints being pretty crap. So I'd have had to buy new arms (which I have) but then press the new bushes out & poly ones in.

So at some point I'll pick up another couple of arms second-hand & whack the bushes in then.

Does anyone know the torque settings for the bush ends of the upper & lower arms? I have the BMW Maintenance CD-rom which is great, but the info on the torque settings is great, but the descriptions of the parts doesn't marry with that of the descriptions used within the tutorials.

In the tutorial it refers to;

control arm, thrust strut, tension strut

Yet this is what descriptions are used in the torque specs;

31 12 ... Control Arms and Struts
Leading strut to front axle carrier (tightened in normal position) 135 13,5
Control arm to front axle carrier (tightened in normal position) 77,5 7,75
Control arm to spring strut 85 8,5

The first figure is in Nm.

Which of these descriptions relate to the lower & upper arms, which is which? I thought the 'leading' strut might be the lower arm, but it has a slimmer bolt than that of the upper arm, yet appears to have the higher torque figure!!! Eh?

What exactly is the control arm to spring strut? I thought it might be the plate with the 3 bolts that is attached to the underside of the strut - am I right?

Please help. I still have to change the upper arm on the drivers side, the bolt & nut are well solid...., although the lower arm is done.
So at the moment, all I have done is to tighten the fixings up (using Kevs635csi great tip of jacking up the strut before tightening the bush fixings, to represent fully loaded suspension) as best I can, the left hand side is totally done, but not torqued to the right setting.

Cheers,

Dave [/quote]

[UKDaveJ]

Well, my car feels TREMENDOUS with complete new front control arms, the steering now feels alive, not dead as it did before.

That proves to me that 20yr old ball-joints should be changed regardless, so I personally wouldn't recommend just changing your bushes if your car has;

a) never had the control arms changed complete, or
b) your car is low mileage*
c) your steering is sharp already.

Please also note that the ball-joints didn't show any real sign of wear until I took the arms off, then play was quite evident.

(*) My car has covered just 92,951 miles as of this post. According to the huge history that came with it, the arms & or bushes had never been changed.
(My car was built late '83, registered 1/1/84.)

The difference to the steering is simply staggering & I don't believe that simply changing the bushes would have done this alone.

Also, the brake judder has completely disappeared!!! One happy bunny.

What I've found is that my brakes are way better than I thought they were when stomping on them from high speed, I didn't dare before unless I was forced to by an errant driver wandering lane to lane etc!
Then my arms, wrists & shoulders got the kind of treatment people who use those vibrating 'weight-loss' machines are used to.....!!

As I didn't get answers to my torque setting questions in time, I did as kevs635csi suggested by text to my q of what settings......"tight as f**k".
Cheers Kev!
Made me laugh & was kind of what I was thinking anyway!
The bushes are sleeved after all.

Thats what I did in a way, using a bit of common sense for good measure taking into account functionality & bolt size etc!

It's not a job I particularly enjoyed doing, 20yr old bolts don't want to move without good penetrating 'oil' & plenty of physical effort, even to the extent of splitting one of my 17mm sockets....., which then took the corners off one of the (3) bolt-heads that hold the tie-rod plate onto the bottom of the strut...

But persist, the payback is worth it at the wheel

Dave

[kevs635csi]

nice one dave ! good to see a diy'er sorting out the problems rather than shelling out for some monkey to do it in a garage

[UKDaveJ]

nice one dave ! good to see a diy'er sorting out the problems rather than shelling out for some monkey to do it in a garage

Thanks Kev!

Will b doin a post (for help) in a mo ref compression testing....