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#1 Rear ride height

Posted: Sat Aug 24, 2013 1:13 pm
by andrewh
I just lowered my car onto its rear wheels and its sitting too high!! typical. I bought CMC rear springs, koni Classics and was advised by CMC to fit spacers top and bottom of the spring. Any advice out there please? Not looking forward to taking the shockers out again and compressing those spings once more! Of course it has not run down the road and may settle but it seems about an inch and half too high

#2

Posted: Sat Aug 24, 2013 3:12 pm
by 1954Etype
It should settle down.

#3

Posted: Sat Aug 24, 2013 3:23 pm
by andrewh
ah, that sounds promising. quite a long way to go though. I wonder whether I will have to take one of the spacers out though? Am I right in assuming that rear ride height is a function of the spring length and tension? Presumably fitting the spacers as per CMC advice tensions the spring causing the ride height to increase? However, if the car drives around and the springs settle maybe we get back to where it should be. Anyway, thanksfully I remembered to get the top shock absorber bolts in the correct way around so they can be removed without having to drop the IRS.

#4 Re: Rear ride ehight

Posted: Sat Aug 24, 2013 6:47 pm
by Dave K
andrewh wrote:i just lowered my car onto its rear wheels and its sitting too high!! typical. I bought CMC rear springs, koni Classics and was advised by CMC to fit spacers top and bottom of the spring. Any advice out there please? Not looking forward to taking the shockers out again and compressing those spings once more!

Of course it has not run down the road and may settle but it seems about an inch and half too high
Have you just dropped it to the floor and not rolled it back and forth at all? Every E-Type and probably other car will be the same. A quick drive round the block should see it OK.

Dave

#5

Posted: Sat Aug 24, 2013 11:15 pm
by andrewh
no indeed I have just dropped it to the floor as I have not got the front suspsion fitted yet. Too early to panic I guess.

#6

Posted: Mon Aug 26, 2013 3:55 am
by johnney
Did you tighten the shock absorber mounts after lowering the car or before? The suspension should be loaded first, same for the front shock absorbers and wishbone fulcrums. Tightening any of these without the suspension loaded puts unnecessary strain on the rubber bushes and increases the ride height. Better to lower the car onto axle stands placed under the splined hubs, then tighten, jack back up, refit the wheels and lower down.

#7

Posted: Mon Aug 26, 2013 7:45 pm
by andrewh
Certainly the shock absorber mounts were tight but not te radius arm to wishbone yet. I feel sure it will settle but it's very high and rock solid. As I said in advice from CMC it's on Koni Classics at no two tension with spacer top and bottom. I reckon she will not need spacers with brand new springs. Anyway wait until the front suspension is on and roll it around a bit. Looks like a tractor right now. 11.5 inches from lower IRS plate to floor. Should be 7.9 inches!!

#8

Posted: Tue Aug 27, 2013 11:43 am
by johnney
andrewh wrote: it's on Koni Classics at no two tension with spacer top and bottom.
not sure what you mean by that ! as the springs are never in tension only compression. I would be interested to know why spacers were recommended, unless the springs are shorter than normal or the spring platforms are closer to the lower mounting points on the shock absorbers. One or the other must be wrong.

#9

Posted: Wed Aug 28, 2013 7:45 pm
by andrewh
Well I am not sure what I meant by that as well! I think it must have been a typo. So to clarify, I checked with CMC what they thought would be the correct set up before fitting up my rear end. They recommended their springs which they believe to be the most accurate to the original performance, and they also recommended fitting a spacer top and bottom, so I did, plus Konis classics. Whilst there is no adjustment of rear ride height that I can see, if a spring is sagging then fitting a spacer will raise it. I assumed that if CMC make the springs then they know that they are too short without the spacers. I hope this is correct or else I have to take out the springs and shockers to remove one or both spacers. Early 3.8s had spacers but then they were deleted . What I dont know is what then happened to spring lengths. Ah tricky game. I hate trial and error !

#10

Posted: Wed Aug 28, 2013 8:41 pm
by Heuer
Are you sure they are not the retainers as the packing(spacers) rings were only fitted to the really early cars (pre 860007/850136? There are two retainers per shock which locate the springs centrally. Sounds to me as though you have the wrong springs or shocks. Check with CMC.

#11

Posted: Wed Aug 28, 2013 11:11 pm
by PeterCrespin
Alloy spacers were fitted around the shock bodies to lift the ride height at various times, not merely early cars. E.g. in 1966 the E-type had them. Those spacers/collars were about 3/8" thick, which raises the ride height by more thn that due to the geometry.

Simply dropping a car onto its wheels will always result in far too much height until it has rolled far enough to let the contact patches move outboard. Dropping the wheels onto glossy magazine paper helps the suspension slide into position with the wheels at proper track and camber and ride height.

Pete

#12

Posted: Thu Aug 29, 2013 2:23 am
by wol916
I had the same experience when I lowered mine onto the floor (I'm using the original springs) then I thought bumpers, tank, spare wheel, seats, glass, exhaust, etc there is a lot of weight in boxes around the garage and not where it should be compressing the rear springs so I decided not to worry about it until the car is on the road. If it's still a problem I'll look into it, I have adjustable platform dampers fitted so should save a lot of effort.

#13

Posted: Thu Aug 29, 2013 6:43 am
by Heuer
Pete

Were those 'spacer's used to improve sagging suspension caused by weak springs? According to the spares catalogue there should be a packing ring at the top of the coil springs and a 'seat' with a retainer underneath at the bottom.

Andrew - do you have any pictures?

#14

Posted: Thu Aug 29, 2013 10:21 pm
by PeterCrespin
I forgot to mention I meant the 2+2 as my 66 example. Presumably they fitted rings to counteract the fractionally lower ride height resulting from the extra weight of the 2+2? Not sure why they came and went on other models at various times.

Pete

#15

Posted: Fri Aug 30, 2013 7:51 pm
by andrewh
good feedback , thanks Guys. My Konis are fitted with the retainer ring and a spacer/packer top and bottom. Believe me, I checked and rechecked this with CMC as it is clear from the parts catalogue that they are not fitted at my chassis number 860897. I mentioned this fact, but again was told that the correct set up with the CMC springs were two spacers. Lets hope she settles down as Pete mentioned. If I have to take them out, well I will but I am not best pleased as its a hell of a job. I am not sure how you can get then nylod off the top rear absorber mount, let alone get it back on again. Its very tight up there.

Back to the very early cars requiring packers, why was this, The top IRS mounting would have been in the same place and the lower mounting the same, why would you need spacers if the springs were the standard length?

EDIT

actually the more I think about this the more I consider that all the packers do is to put the springs under tension. Therefore there will be less sag on the body, and as mentioned earlier when the fuel tank, bumpers etc go on it will add to the weight . I cannot really get this sorted until she has been down the road, lets just hope no body seems me in my E Type tractor!

#16

Posted: Sat Aug 31, 2013 3:43 am
by johnney
andrewh wrote:Actually the more I think about this the more I consider that all the packers do is to put the springs under tension. Therefore there will be less sag on the body, and as mentioned earlier when the fuel tank, bumpers etc go on it will add to the weight . I cannot really get this sorted until she has been down the road, lets just hope no body seems me in my E Type tractor!
The springs are never under tension, only compression. Fitting spacers on top of or under the springs does not change the load on the springs or the amount of compression,(except at full extension of the shock absorber) it only increases the ride height.

#17

Posted: Sat Aug 31, 2013 9:28 am
by PeterCrespin
The spacers don't put the springs under more pressure except when the shock absorber assembly is fully extended, which only ever happens on the shelf or with the wheels dangling. When fitted to the car the springs will be compressed by the mass of the car and all the spacers do is raise the car under the same static load and spring compression/length.

Pete

#18

Posted: Sat Aug 31, 2013 2:23 pm
by johnney
PeterCrespin wrote:The spacers don't put the springs under more pressure except when the shock absorber assembly is fully extended, which only ever happens on the shelf or with the wheels dangling. When fitted to the car the springs will be compressed by the mass of the car and all the spacers do is raise the car under the same static load and spring compression/length.

Pete
Peter, that's what I just wrote!

#19

Posted: Sat Aug 31, 2013 6:07 pm
by Dave K
andrewh wrote:good feedback , thanks Guys. My Konis are fitted with the retainer ring and a spacer/packer top and bottom. Believe me, I checked and rechecked this with CMC as it is clear from the parts catalogue that they are not fitted at my chassis number 860897. I mentioned this fact, but again was told that the correct set up with the CMC springs were two spacers. Lets hope she settles down as Pete mentioned. If I have to take them out, well I will but I am not best pleased as its a hell of a job. I am not sure how you can get then nylod off the top rear absorber mount, let alone get it back on again. Its very tight up there.

Back to the very early cars requiring packers, why was this, The top IRS mounting would have been in the same place and the lower mounting the same, why would you need spacers if the springs were the standard length?

EDIT

actually the more I think about this the more I consider that all the packers do is to put the springs under tension. Therefore there will be less sag on the body, and as mentioned earlier when the fuel tank, bumpers etc go on it will add to the weight . I cannot really get this sorted until she has been down the road, lets just hope no body seems me in my E Type tractor!
Andrew,

It's not that hard to remove the rear shocks while they are in place, if you haven't already set the camber then that is what you will have to do.
To get the setting links in place the car will not compress enough to allow them to fit, even with the ratchet straps and the shocks off I had a struggle.
When it says in the book have the fuel tank full and the weight of an average person in the car is tosh, the suspension hardly moves.

Dave

#20

Posted: Sun Sep 01, 2013 11:46 am
by PeterCrespin
johnney wrote:Peter, that's what I just wrote!
Yes, but it wasn't there when I started the reply on an iPhone in a services somewhere, while my son was getting the food in.

By the time I posted it, I was in the Virgin Clubroom at Heathrow, drowning in a constant flow of champagne, smoked salmon and Espresso Martinis, so thass my excushe...hic!*^+

Pete