Suspension upgrades?

[mikeyb]

just for the record, the last lot of rear trailing arm rear poly bushes I bought for the Stag came from Canleys, who were the cheapest last summer.  Tightened up the back end and (in conjunction with greasing the driveshaft splines) eliminated the dreaded twitch!  From memory about 6 quid each.

[Richard B]

MikeyB wrote:

Tightened up the back end and (in conjunction with greasing the driveshaft splines) eliminated the dreaded twitch!  From memory about 6 quid each.

I prefer Chris Witor's bushes with the stainless steel inserts; more expensive, but not going to seize on the bolts.

Yes, loads of grease on the splines (Molybednium Disulphide); although the Datsun driveshafts are the 'next generation' much better :)

'Gease that shaft', cue more smutty jokes?

[Slimboyfat]

Richard_B wrote:

I prefer Chris Witor's bushes with the stainless steel inserts; more expensive, but not going to seize on the bolts.

Not always the case. Had to do the dreaded bottom ball joint's on one of the 2.5's last week. The bolt had seized on the stainless steel tube in the Superflex bush despite copious amounts of copper grease on assembly. It has been my experience that it's just as likely for mild steel bolts to seize in stainless tubes, as it is for mild steel bolts in mild steel tubes.
As a postscript am I alone in having had these things (Polybush or Superflex) fitted to my own cars for that long that they are wearing out? The Superflex track control arm bushes on one of our cars are getting very moth-eaten, and caused an advise on the last MOT.

[Dizzy]

jcarruthers wrote:

A shock absorber absorbs energy from the spring - the spring does not absorb shock, but stores energy. The spring takes the energy from a road wheel going up and down and stores it rather than directly putting that energy in to the car. The shock absorber then lets out this energy in a controlled way. ....

In my view, this is almost there but not quite right.  Let's take it to a theoretical extreme... i.e. an almost rigid damper which prevents the spring being compressed at all when going over small road bumps.  The spring would be absorbing no energy, and neither would the damper.  The energy would be transmitted into the body of the car as it precisely followed the bumps in the road and your teeth would rattle.

In real conditions, the spring absorbs the energy ('shock') from a bump and immediately tries to release it as rebound.  The damper damps the rate of 'bound and rebound' so, as sorbs says, it is, er... a damper, not a shock absorber.  

A tiny part of the energy will be absorbed by the damper (with most of it converted into heat, not "let out in a controlled way") but this is co-incidental and unwanted.

Right, now let's solve the Burma crisis.

[Mj17]

All this talk of dampers has me asking a question...

I've got a feeling my front dampers are on their last legs (gaiters long gone and mysterious oil on suspenssion parts with nothing else above them) but I'm buggered if I can work out how to test.

The classic is "press down on the corner and count the number of bounces - should be 1.5" but pressing down doesn't move anything - it takes a bit of a jump and full body weight...but by the time I've jumped off and landed the bouncing is over!

Do I just need a fat friend?

Slimboyfat wrote:

Not always the case. Had to do the dreaded bottom ball joint's on one of the 2.5's last week.

Not what I wanted to hear - guess what I'm planning to do on the BBS this weekend... :(

[GreenV8Machine]

lol, when i canged mine i took off the leg and the alloycap, tapped out the damper and a big torrent of fluid went all over the floor. I wasnt that excited, but the damper had leaked. No rust though!!!

[Barry Acclaim Guru]

Simple harmonic motion is the answer. How much energy do you have to put into ocilation in order to get it to bounce up and down, a lot means they work well, and a little means that they are stuffed, as a basic rule of thumb.

the acclaim needs at least three bounces to get the gasses doing there dapening thingy, whilst the estate is well difficult to bounce with the new dapeners on.

b

[Richard B]

Slimboyfat wrote:

As a postscript am I alone in having had these things (Polybush or Superflex) fitted to my own cars for that long that they are wearing out? The Superflex track control arm bushes on one of our cars are getting very moth-eaten, and caused an advise on the last MOT.

Presumably they were yellow bushes if they are that old?

First I've heard about them dying; but not surprised, anything has a finite life. I think the rubber bushes are expected to last  about 3 - 5 years. I've always thought the polyurathane bushes would be 10 - 15 years.

I suppose the life depends on the enviroment; extremes of temperature, salt or grit from the road etc?

[Slimboyfat]

Richard_B wrote:

Presumably they were yellow bushes if they are that old?

No they are purple. My mother used to have yellow ones on her car. When that car came off the road due to rot I salvaged the track control arms for the recently fitted ball joints, and those Superflex yellow bushes. To be honest looking at them now I wouldn't use those bush's on another car. The purple bushes are on another car that had them fitted 7 years ago. It does about 15,000 miles a year, so I suppose they lasted quite well. They will be replaced with Polybush Red items as soon as I can get motivated to take it apart again.

[thescrapman]

I would also guess that some of Mr Fats (sorry.. :-) ) cars do get quite a bit of spirited use, daily, over quite a long period.

Mj17, my ball joints required 7 tonnes of pressure to release them apparently. Good Luck!

I had been advised an exchange arm might be the way to go, Mr Witor doesn't do them anymore unfortunately.

I did also have a spare Balljoint that needed using.

Cheers

Colin

[Mj17]

Humm, so do I try and potentially put my self off the road with only weekend access to the car (and only 1 weekend between this and Le Mans) or roll with a split ball joint gaiter till after Le Mans...?

[thescrapman]

Tape up the split gaitor

Cheers

Colin

[Slimboyfat]

thescrapman wrote:

I would also guess that some of Mr Fats (sorry.. :-) ) cars do get quite a bit of spirited use, daily, over quite a long period.

The car in question is Mrs Fat's mota, she did for the bush's, not me :o.
She's driving the Stag now, I wonder how long those rubber bush's will last? ::)

[Mj17]

That's one I've not seen before...

"Drive it like Mrs Fat's wife stole it."

[piman]

Hello GT6,

"lol, when i canged mine i took off the leg and the alloycap, tapped out the damper and a big torrent of fluid went all over the floor. I wasnt that excited, but the damper had leaked. No rust though!!!"

When damper inserts are fitted in Macphearson struts, it is usual to fill the casing with oil so as to help heat transfer. I.e. there should be oil around the insert as well as in it.

Alec

[GreenV8Machine]

This badboy was well and truely fudged! When pushing the damper down the fluid sploodged out of the bottom of the damper, no return.

I didnt know triumph did that to their struts.