Knocking Suspension Top Mount

[M@tt 77]

right well today i bought 2 new top bearings from GSF to hopefully irradicate the knocking in my suspension. So when i got home i proceeded to remove my suspension struts to replace the bearings.

 

After removing the drivers side strut it was clear to see that the bearing had pulled itself apart and needed replacing. However the strut nut refused to undo itself despite coming undone a few days earlier so that needs whipping off tomorrow with an impact gun.

 

So then it was onto the passenger side strut instead. The passnger strut bearing seemed not too bad, there was a bit of a mild grinding noise in parts as it rotated, as though there was grit in the bearing grease so i replaced the bearing. However i found that on the passenger side the top mounting plate was loose despite the strut nut being done up fully. I thought nothing of it intially however once i had replaced the bearing and put everything back together it started to bug me that this wasn't right.

 

As far as i can deduce i think the rubber donut is not taking up the slack between the top cup that sits ontop of the bearing and the top mounting plate! would this seem correct?

 

i have taken a video of what is happening

http://smg.photobucket.com/albums/v230/meb...nt=0ede5b7b.flv

 

these were group N rubbers (apprently) from skip brown and i've done less than 4K in the car on them so i would have thought they'd last a bit longer than this?!

 

any suggestions?

 

Clearly this play means that as weight comes off the wheel it would allow the strut to fall and this would cause the top dished washer to bang into the mounting plate as it moved down. i assume the dished washer and mounting plate should usually be in contact with one another at all times as the donut should be trying to push them apart.

 

any help appreciated

Edited April 25, 2007 by M@tt

[richsmells 2]

Funny you should mention this, I have SBC rubbers on mine and the suspension knocks from the topmounts I think. I have SBC springs too on new OE dampers.

 

When I put the struts back together they were fine though, no play like in your video. It's getting pulled apart at the weekend to fit new bearings, droplinks, track rod ends, arb bushes and wishbone bushes so we'll see what the problem is?!

[M@tt 77]

can some one confirm whether the dished washer that sits on the top of the strut (the one which teh strut nut sits in) should sit flat tight against the domed top plate once it is all built up?

 

I've trawled throught eh various suspension pics i have and there seems to be a mixture. Some are flush up against it whilst others have a 5mm or so gap

[GLPoomobile 958]

Off the top of my head, the only dished washer I can think of is the one with the tag that the brake warning light earth wire connects to. If that's the one you mean then I'm not even sure it's needed.

[M@tt 77]

sorry the dished cup would be a better description rather than dished washer (small thing about 5cm diameter)

Edited April 26, 2007 by M@tt

[pacey205 2]

Which bit on here

 

[Ahl 4]

can some one confirm whether the dished washer that sits on the top of the strut (the one which teh strut nut sits in) should sit flat tight against the domed top plate once it is all built up?

 

I've trawled throught eh various suspension pics i have and there seems to be a mixture. Some are flush up against it whilst others have a 5mm or so gap

No. But as it moves about a little, it'll look different depending how the wheels are pointed.

[M@tt 77]

Which bit on here

 

3rd line down of Part 4 its the solid metal cup bit about 5cm in diameter that sits in the hole in the top mount pan which has the threaded top bit of the suspension strut poking through it and the nut then tightened onto it.

 

hope that makes sense,(few pints at lunch time )

[pug_ham 244 3 Cars]

With my group N rubbers the washer you are asking about Matt is flush against the top mount plate when fitted to the car & on its wheels.

 

There is only usually a gap with the standard rubbers.

 

Graham.

[Ahl 4]

The washer on mine has a small gap, but thats with Sprintline shocks on it (and grpN rubbers).

 

If I remember rightly there wasn't a noticeable gap when it had OE Streetline shocks on. Dunno what thats all about.

[welshpug 1,657]

theres a small gap in mine too, even when i had new bearings and rubbers. *standard

Edited April 27, 2007 by welshpug

[M@tt 77]

Next palava in the strut changing saga came last night when trying to undo the suck top nut on the drivers strut with 309Pug's cordless Sealey Impact Gun (not a cheapo one). We found that my previous ring and flat spanner attempt had rounded the thread slightly on the top of the threaded bit and so the nut has now become stuck half un done!! It would neither undo or retighten using the gun, the whole shaft kept spinning. granted we were trying ina pub carpark in the dark at 11pm last night

 

My shocks are AVO adjustables and so have that little hex adjusting nipple on the top so have no allen key hole to put a key in to to stop the the shaft from spinning.

 

Not sure whether it's worth taking down to a garage and get the air compressor impact gun on instead to see if that works any better?

 

I've read some posts about clamping the shaft with some mole gips but tbh if it it wont come undone with an impact gun i'm not holdig out much hope for a set of molegrips to keep it from turning!

 

Getting pissed off with it now arse!!

Edited April 27, 2007 by M@tt

[welshpug 1,657]

NEVER clamp the damper rod if you want them to work again, rattle gun should get it off, but to make 100% sure it will, spin the nut back tight, then carefully run a hacksaw through the damaged thread to see if you can clear the damaged metal out of the way.

 

failing that file it down.

 

have you tried pulling off the adjuster knob? there may still be a kex in there you can stick an allen key into.

[Rippthrough 98]

Have you got a rubber strap wrench, or even an old fan belt? Hold the rod with that, then use the impact gun to knock it forward and back until it straightens the threads out bit by bit.

 

The adjuster knob is gun drilled all the way down and is one piece, so don't pull it off or you'll need a rebuild.

Edited April 27, 2007 by Rippthrough

[M@tt 77]

Yeah i was only going to try clamping it right at the very top where the shaft wouldn't have been going in/out the strut so not damaging the seals.

 

Yeah the adjuster thing won't come out and is quite small so I dont fancy using that to try and prevent the strut from spinning as i'll probably snap it off.

 

My rubber strap thing snapped but will see if i can fashion something.

 

The impact gun wasn't even letting it tighten the nut back either last night it seemed to have got itself stuck on the damaged thread. I'm going to have another bash when i get home with the gun. I had a brief go last night once i got home but letting off an impact gun in my apartment at 11.30pm didn't go down well with the missus who was sleeping

 

If not it will be off down to kwick-fit tomorrow mornig to get their air gun on it, hopefully that's a bit beefier.

[M@tt 77]

Hurrah good news!!!

 

After 10mins of ragging the nut back and forth with the cordless impact gun which Chris (309Pug) had kindly lent me, i finally got it off

 

Where the spanner had smoothed the thread it had caused the nut to start cross threading with the strut thread, so tomorrow morning i'm off round Paintguys and he's going to restore the thread on it with his fancy snap-on kit

 

Oh and the wobbly top mount isn't wobbly anymore, i removed the strut again and using the impact gun i did the nut up nice and tight(copperslipped the thread though so no chance of seizing ) and the top cup is now flush up against the top pan and the whole thing is solid, i guess i must have made the school boy error some how of not tightening the nut up fully however i did compare the 2 rubber donets and found the previoulsy loose side donut was about 3mm shorter than the other side. This could cause the top cup to not be in contact if it was suffiently short enough though.

 

I am now seriously contemplating getting myself one of these impact guns as they are a fantastic bit of kit. It made tightening/undoing everything a piece of cake. Spring compressors did in seconds!! we used one on a beam rebuild recently and was a god send also.

 

So its all systems go on the suspension front, fingers crossed this does cure the knocking noise otherwise its back to the drawing board.

 

I love it when a plan comes together

Edited April 27, 2007 by M@tt

[Rippthrough 98]

We've got a makita one in the workshop - superb bit of kit - certainly powerful for a battery unit.

Wouldn't have been cheap though.

[djinuk 2]

i have a snap on one and its never failed me, the batterys are not cheap though

[M@tt 77]

not cured the knocking so that means its wishbones, driveshafts or engine mounts...

[Rippthrough 98]

You tried retorqueing the wishbone bolts, they can knock slightly if they are undertorque, and a simple check for loose bolts won't pick it up.

[M@tt 77]

right Well i'm £84 down as i've just ordered 2 new wishbones from www.buypartsby.com here's hoping that cures the knocking!

 

the wishbones were the only original thing left of the original suspension so and condition unknown. I couldn't spot much movement in them but you can never be sure.

 

heres hoping

[welshpug 1,657]

have you checked the hub to balljoint clamps?

[M@tt 77]

yep i checked the holes weren't ovalled and they weren't and i bought new pug bolts as well still didn't make a difference

[pug_ham 244 3 Cars]

You shouldn't be able to spot any movement in the balljoints with them all clamped up tight.

 

Graham.

[M@tt 77]

well i've fitted the new wishbones and the clunking has gone!!

 

hurrah

 

only thing is i found both the back bolts weren't amazingly tight!! now have i just spent £84 when i could have just tightened up 2 bolts?!!?? that'll teach me

 

well i've kept the wishbones so i can refit them when these ones go and see whether it was them or not.

 

Those back bolts are a bar stewrd to get tight though , not much space to move your spanners in especially with arb and track rod getting in the way.