Spring & Dampers

[Markwoodbridge]

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Brief update; Dampers now back from Nitron and ''softened by about 75%" The front springs fitted are 325 and the rears 150.
I'm borrowing a pair of 300 front and 175 rear to see which is "best".

Off to Westfield later to get new bushes fitted to my rear trailing arms as all mine were done for after about 3,000 miles.

Will let you know how it seems, softer probably.

[Alan FIAT]

Hello there.
Its interesting to see the debate re standard rear suspension bushes wear and suspension binding being raised again. I checked my bushes last time and found them to be ok, they are still ok and have done around 10,00 miles since I fitted them. Mostly road work I admit, but some track day and sprint stuff.
I mentioned previously that after I bought my car the rear suspension was not good, being somewhat unpredictable. I had experienced this before on multi- link live axles and checked to see if the bush's outer metal sleeve was a similar same length to the inner one, they where. Thus when the axle links twisted during cornering the outer sleeve would bind against the chasssis. Solution was to buy new bushes and machine the outer sleeve about 16th inch shorter than inners each side of bush.
As discussed on here before, on refitting links, the car should be supported on its suspension, so that the inner sleeve is in its normal loaded position before being tightened up. Personally I tighten my link fulcrum bolts so that there is no movement of inner sleeve against chassis, but can appreciate the 'keep em loose' view to remove friction from suspension movement.

Regards
Alan

[Westfield 129]

Don't torque the bushings down tight (around 5 lb.ft torque turning both nut and bolt is fine) and they will last thousands of miles longer, especially in the rear.

Early cars will need to be torqued a little more, but not much more. Late cars have the rear suspension bolts in double shear, which helps to increase bushing life, and allows very low bolt torque. You can get the rear suspension mount shear plates from Westfield and weld them to the early car's chassis.

I hope that your rear dampers are at least 14" long, compressed.

I have tried 150 lb.in. springs. They help at taking the sharp edges off the bumps, but are still a little too stiff.

[erictharg]

As Jan says, the biggest problem with the stock rear suspension is that the dampers are too short, meaning there is virtually zero droop. So, any slight roll, or bump, and you pick up a wheel. Longer dampers with softer springs will make the rear much better. Better ride and more predictable.

[Westfield 129]

Sorry,

Small error:

Make that extended length 14" for the rear dampers.

[biggles]

Interesting - my early car is currently on 14 inch open length dampers front and rear, but obviously is different to most of you guys' cars being a bitsa of ford/triumph components.

Cheers all
Biggles

[xkfeng7]

When I first heard from Jan that the bushings don't last very long, I thought he was nuts.
My westfield had about 3k miles on it when I bought it. I put on another 750, and then checked and the rear bushing rubbers was torn to bits. I setup my rear to allow the entire bushing to rotate on the bolt and 1800miles later and the new bushings a're just fine. As Jan says, there's precious little rubber thickness there to twist. Maybe if you run on very smooth roads and your suspension setup is stiff enough to minimize suspension travel then your the bushings will last substantially longer. I personally like the soft rear setup that Jan recommends.

John

[LA 11 builder]

I did the same thing with the same results: it just frees up the suspension to work as intended. A true Top Tip!

[Splat]

So, I went with the Protech setup. Firstly, if you visit their premises in Wiltshire you will receive a MUCH better price than online. They told me that such a deal would be available for any of us if we collected the shocks in person. Believe me, it was a MUCH better deal

Fronts are 12.5" X 1.9" , springs of 350lb by 7". Rears 14" X 1.9", springs of 150lb X 9". All were custom-valved for the lighter car. Double adjusters.

Points: Longer rears would allow the axle to contact the chassis rails. 14" is the longest to go for. The longer fronts mean that the steering rack contacts the upper wishbones when the suspension is at full droop. This I consider highly unlikely on the move. So did the MoT tester, who said that it was OK.

All bushes were replaced, front and rear. I also replaced one lower wishbone when I found the bushing eye was worn to an oval. The bush just fell out! Westfield had one in stock. The welding was shocking and the paint appalling! I filed off the weld splatter, keyed the paint and repainted along with all the rest of the suspension components. All bushing bolts were torqued to 6 lb ft and paint-marked. I also took the opportunity to refresh the rest of the chassis components: painting callipers, rebuilding the leaky diff, sorting the hand brake, etc.

I set the geometry myself, with basic kit in my (long) single garage. I knew that there was a reason that I so massively over-ordered the gravel for the drive! It makes great ballast. I'll have it checked by a pro, but it feels good! A steady two mile run around the block before it's MoT this afternoon, which it passed with numerous positive comments, followed by a quicker lap afterwards.

It's smooooooth. It feels so much more supple. The valving is fully open, so I've some fiddling to do, but corner weighting first.......

[jonclancy]

Just out of interest, how long does it take to change the trailing arm bushes?