Torque Settings - Rear Suspension

[Retroman]

Hi,

Previous threads on torque setting seem to be US.

Can anyone point to a definitive publication which gives torque setting for rear shock bolts and anti roll bar drop links?

Should the bolts on the anti roll bar drop links be tightened at maximum sag or when the suspension is under static load to ensure ARB engages effectively mid corner etc.

Nigel.

[christopher storey]

The final tightening should be done with the suspension under load and at mid-travel. Any other setting will a.distort the overall suspension geometry and b. lead to premature failure of the rubber components

[mgcjag]

Nigel.....only some torque settings are in the service manual......for any others just use standard torque charts for the size bolts your useing....Steve

[Retroman]

Thanks Guys,

All done up properly to find change of springs from well known supplier have reduced not increased ride height.

Correct spec length at 10.5 ins and 11mm diameter coils..... but must be soft as rim of wheel now disappears above the wheel arch edge.

Treeeemendous waste of time and effort.

Yes spacers have been refitted.

Can anyone comment on decent source of quality springs rather than suspected 'China Specials' and what the spring rate the springs should be for a series 2 2 + 2.

It grounds out with ease when travelling at the legal speed limit on mild undulating roads.

Sitting at 6 1/2 ins from ground to rear subframe.

Not a happy Teddy.

I read somewhere 325 to 350 but cannot find reference at the moment.

I am going to try and find somewhere in the north west to have these saggy springs tested and bounce them back for a refund.

End of rant.............for the time being,

Nigel.

[abowie]

Go back to your old springs and put in some spacers.

[TGN]

Nigel I was going to order a set of springs from here.
https://britishclassiccarparts.com/coll ... rer_jaguar

But when I removed my rear shocks I found the platform to eye was shorter that it should be on one end. So I turned up some 20mm spacers to correct this

[bitsobrits]

I read somewhere 325 to 350 but cannot find reference at the moment.

Nigel.

Stock rate for a 3.8 FHC is 268 lbs, so 300 might be close for a +2. I run 275's (which are a readily available increment) and find that very satisfactory. You might look at the tuner/racing supply houses for decent quality springs. Nothing special about the E type springs, jut get the correct ID and spring rating and correct length.

I would add that adjustable perch rear dampers are really the way to go to allow getting the rear ride height dialed in.

[Series1 Stu]

Stock rate for a 3.8 FHC is 268 lbs, so 300 might be close for a +2. I run 275's (which are a readily available increment) and find that very satisfactory.

I would be interested to know where your information came from because I've looked for this for quite some time without any luck. I think we have previously failed to come up with a figure here on this forum so this is very helpful information.

I shouldn't imagine that there would be any discernable difference between 268 & 275 lb/in, in fact the tolerance ranges would probably almost completely overlap.

Regards

[bitsobrits]

The spring specifications are in the factory manuals. I believe I may have calculated the spring rates from the the wire diameter and number of coils. A little bit of Googling gives useful spring rate calculators, and much information on factory spring rates for these cars. 4.2 FHC had softer rear springs, btw, about 250lbs/in.

As far as the difference between 268 and 275, the difference would be undetectable. My experience from my track days was that it took at least a 10% change in rate to be noticeable at all, and I typically moved in about 20% increments when trying different combinations.

[steve3.8]

Original 10½" springs i have tested at 190lb per inch of compression, as said no reference is visibly available .The only reference i remember is Graham Hills car in Porters book being 150lb.

[bitsobrits]

Please see the link to a post below which shows the referenced Factory Manual specifications, which will yield the ~250lb/in and ~268lbs/in figures I mentioned above. I would say the article on Mr. Hills car must certainly be incorrect.

viewtopic.php?t=6841