Adjustable reaction plate for ride height adjustment-advice

Alty Ian · Post by **Alty Ian** » Wed Dec 30, 2015 7:03 pm

I fitted a Rob Beere adjustable reaction plate which has been good and makes front ride height adjustment a doddle.

However, although I followed the technical guidance provided, it wasnt very specific about the starting point, I did use a bar of the correct length in place of the shock absorber and decided to set the cam at the position 4 (the mid point - there are 7 positions) thinking that I could then be able to raise or lower the ride height afterwards.

That turns out to have been a mistake. Over the last 6 months the torsion bars have settled down and the ride height is too low with the cam in position 7.

The purpose of this post is to warn people that they need to allow for torsion bars to settle down a lot more than one would expect. And mine are originals, not replacements and fitted on the correct sides (they are marked on the ends).

So I have had to drop the suspension today and turn the ear one spline round to create more adjustment, roughly one spline seems to equal the full 7 positions of the cam so I'm back at position 0 or 1 now before it starts settling down again.

andrewh · Post by **andrewh** » Wed Dec 30, 2015 7:09 pm

Ian, you must have been reading my mind. What a useful post, although I am slightly disappointed to hear that the adjustability only equates to one spline. Almost not worth it on that basis?

My 3.8 settled a bit and actually to my highly critical eye, appears to be slightly lower on one side than the other. Nobody else can spot it but I wonder whether that is possible. I guess part of the reason for using the link arm is to avoid setting each side differently? And as I did use that I suspect that mine is not lower one side.

Anyway, rambling on there! I was thinking of fitting the Rob Beere adjustable to my next restoration to make the exercise easier, but if you are correct, don't think its worth it

vipergts · Post by **vipergts** » Wed Dec 30, 2015 9:32 pm

It's worth it

My car dropped.....There was sufficient adjustment available to me to correct it and also set the different side to side

If I were fitting one again I'd set the ride height higher to start with to allow for settling and allowing the adjustable unit to serve as a device to set it absolutely correct side to side front to back

Alty Ian · Post by **Alty Ian** » Wed Dec 30, 2015 10:21 pm

Just got in from the garage, what a pig of a job that was, had to remove the exhaust system to get at it, and heat shield etc but its done now.

Despite this, it is defo worth it. The faffing around trying to get torsion bar splines lined up front and aft is a monumental pain, the beauty of the ARP is that the ear can be driven into the ARP hole after the torsion bar is fully fitted, easier to fit and easier to modify/adjust later, well it would be if I set it up right first time. Plus gives you the flexibility to modify the ride, like on track days etc.

One spline is actually a hell of a lot of adjustment if you think about it about 14-15 Degrees I think. As a very rough guide, I reckon each of the 7 positions changes ride height by about 1/4 " although position 0 to 1 is much more than the rest.

If I was restoring an E again I would use one again.

jag68 · Post by **jag68** » Thu Dec 31, 2015 1:27 am

The adjustable plates are worth it. I think playing with the torsion bars has to be one of the worst jobs on the car. When I work with an old set of bars I set the distance on the setting tool 1 inch longer than suggested. In other words I make a new tool. That takes care of the settling. I also find that the cars settle more to the side the driver sits on. In my case the left side. I try to set it up 1/4" higher than the right so when I sit in the car by myself or with a lighter passenger it's level. Adjustable rear shocks help with this of course.

Terry Sturgeon

Post by **mgcjag** » Thu Dec 31, 2015 10:14 am

Hi All......are we forgetting that the torsion bars act as a vernier gauge, one end has 25 splines and the other end has 24 splines this allows for very fine adjustment......if you just adjust them by turning one end only by one spline then you will get a large movement, by moving both ends you get fine adjustment.....if the torsion bars have never been out they can be a pig to remove, but on a refurbished car where everything has been removed and cleaned up they are quite easy to adjust........set them up on quite a few cars now using the original bars following refurbs, once set how often is there ever a need to readjust unless you using it for the track.......if your fitting the adjustable plate thats fine but not really needed for a road car imho

Post by **1954Etype** » Thu Dec 31, 2015 11:41 am

Agreed. I tried fitting an adjustable once but gave up when l was told to file a bit off here and there. I know Ken Verity uses them all the time. The adjustment is too coarse unlike the S3.

PeterCrespin · Post by **PeterCrespin** » Thu Dec 31, 2015 1:28 pm

mgcjag wrote:......if you just adjust them by turning one end only by one spline then you will get a large movement, by moving both ends you get fine adjustment.....if the torsion bars have never been out they can be a pig to remove, but on a refurbished car where everything has been removed .......if your fitting the adjustable plate thats fine but not really needed for a road car imho

The voice of reason.

Alty Ian · Post by **Alty Ian** » Thu Dec 31, 2015 5:06 pm

Job now completed and ride height spot on with adjustment to spare to lift or lower it again. Happy now.

The advice from Terry seems correct to me, the setting tool should be 1" longer to allow for settling effect and still leave adjustment.

dal2.0litrefrogeye · Post by **dal2.0litrefrogeye** » Sat Jan 02, 2016 4:40 pm

Hi interesting reading ! I'm not at this stage yet , but always thinking ahead , one question I was going to ask , there are many adjustable reaction plates out there ( I was urring towards the rob bear one ) are they all that much different, has anyone compared them back to back ? Also has anyone used them for corner weighting ?

Alty Ian · Post by **Alty Ian** » Sat Jan 02, 2016 6:41 pm

dal2.0litrefrogeye wrote:Hi interesting reading ! I'm not at this stage yet , but always thinking ahead , one question I was going to ask , there are many adjustable reaction plates out there ( I was urring towards the rob bear one ) are they all that much different, has anyone compared them back to back ? Also has anyone used them for corner weighting ?

I used the Rob Beere one and its very good quality, would be ideal for corner weighting,... if I think I know what that is.

andrewh · Post by **andrewh** » Sat Jan 02, 2016 6:53 pm

So to be clear. You have removed the reaction plates the ARP, and refitted it with maximum adjustability to raise it when and if it settles?

Edit: I wonder why Jaguar didn't utilise this sort of arrangement when new?

Alty Ian · Post by **Alty Ian** » Sat Jan 02, 2016 7:07 pm

Andrew

No not removed the actual plate itself, the process is as follows;

1. Jack up the car fully and disconnect the shocker, ARB link top bolt, TRE and top ball joint allowing the hub to drop and remove all tension in the torsion bar.
2. Then unbolt the adjusting cam
2. Then unbolt the ear and drift it out,..it goes forward onto the torsion bar, I make a long black line to identify which spline its on before starting
3. Move the ear round one spline and hammer it back into the RP hole.
4. Refix the cam in the new desired position and bolt it up.
5. Then jack up the hub to tension the TB and refit everything.

When both sides done, drop car and measure ride height after it has settled down. The only difficult thing is getting to the LHS bolts as one of the downpipes gets in the way so I removed one.

Normally, when it only needs adjusting, you just put the car on a lift, jack up the front, adjust each cam using an allen key and long bar and its done.

I imagine Jaguar never thought of it, and to be fair once its done and is right its not normally necessary to touch it.

My S3 torsion bars havent been touched in 35 years! and still right height.

andrewh · Post by **andrewh** » Sat Jan 02, 2016 7:43 pm

excellent. well on advice here and previous experience of my non adjustable RP, I think its a worthwhile cheat. I hear what others say but frankly , as has been mentioned it a pain in the rear to do this without a ARP so worth the money I guess thanks Ian

Post by **mgcjag** » Sat Jan 02, 2016 8:00 pm

Jaguar knew all about adjustable torsion bars they were in common use prior to the Etype on the XKs and later are also fitted on the S3 Es

Polse7317 · Post by **Polse7317** » Thu Jan 28, 2016 10:53 pm

I have a difference of height of the car of about 2.5 cm beetween right and left after having rebuilt the front suspension. So I decided to adjust the torsion bar, thinking I had fitted them with a wrong position of the splines , although I have marked them before disassembling. I made a gauge as the manual says and I found a difference of about 2 cm on the gauge ( right// left) and also especially a very big difference with the theoretical measure.(5 cm / photo) I can't believe that I made such error when I remounted the TB !! . does the gauge is a real reference ? I have not measured the height of the car before dismantling.... I humbly need an advice to the right way for reassembly. I think that I must follow the gauge and adjust the TB at that lenght.
Another difference is that the TB on the right is very tight instead of the left one that I can move up and down more easily .
I dread to adjust the TB .....

Another point: the down hole of the gauge is too big ( I followed the manual !)

Alty Ian · Post by **Alty Ian** » Thu Jan 28, 2016 10:59 pm

Yves. I discovered that it is best to set the link bar about 25mm longer than the manual to allow for the TB's settling down. It is quite possible that your LH and RH TB's have different spring rates, especially if they are new.

I hope you have them each on the correct side, they should be marked on the ends,

abowie · Post by **abowie** » Thu Jan 28, 2016 11:12 pm

lataud wrote:
Another point: the down hole of the gauge is too big ( I followed the manual

That'a always confused me as well. I made up a delrin spacer that fits in the hole in the gauge and has the same ID as the shock bolt.

Post by **mgcjag** » Fri Jan 29, 2016 9:18 am

Hi Yves.....you do not have the top ball joint disconnected as per the manual page J.16 this be your problem....... yes you need to reset the torsion bars.....trying to mark them and fit them bact in the original position is neer impossible.......you do realise that tbe bars have different number of splines at each end to create a vernier for fine adjustment.....as said above first check you got the left and right in the correct position.....sometimes tbey are dificult to get in and out make sure you clean the splines and check and remove any burrs on then with a small file....i have always set them at the length as per the manual if they are your existing bars and ride hight was correct on completion....re the hole being too big..dont wory too much just measure your total opening length of the outside of the holes..

Once you have sorted this you must fit the dampers...the suspension should not be allowed to drop without them or you could damage your top ball joint

PeterCrespin · Post by **PeterCrespin** » Fri Jan 29, 2016 9:36 pm

I'm nominating you up for the Suspension Oscar Steve. Best expert on dangly bits.

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

Adjustable reaction plate for ride height adjustment-advice

#1 Adjustable reaction plate for ride height adjustment-advice

#2

#3

#4

#5

#6

#7

#8

#9

#10

#11

#12

#13

#14

#15

#16

#17

#18

#19

#20