Rear end rebuild

[jon1d]

Nice job. Hope you did not get to high off the fumes. Reading the POR15 COSH seems you need full mask and ventilation.
I see you have diagonal reinforced inner end Lower Control Arms for extra stiffness.

[justinb]

Just in the process of sorting out my rear toe.

When I assembled the rear axle the toe was pretty much zero but once bolted up I used a laser from the rear hubs to project forward to an angle of aluminium I had over the front hubs. In the end I spoke to Andy at GD who advised that over the length of the wheelbase which is 90 inches, if you assume an 18 inch wheel the distance between the chassis centre line to the projected laser points on the front on the front should be 3.75mm less than the rears.

Im in the process of readjusting mine now to suit. Im lucky that I dont have the body on, its just a bare chassis so finding the centre line and marking forward is easier.

I've also used the Rob Robinette guide and downloaded the spreadsheet to confirm. I just got to muster up the evergy to go and fart around with it again this weekend coming after putting my back out last weekend trying to do it!

Mines a GD Jag chassis but I've got late model XJS rear axle with vented outboard discs on it but the principle is the same.

[Happy Jim]

Hi Justin,
I’m still body on so that will a bit harder for me (might try though!), I’ve got XJ40 hubs and drive shafts on with the outboard Vented brakes from an X308 which are much nicer to work on/adjust (than the inboard ones).

Had a few days off but just come in from measuring end float and working out shims I need to buy.

Rgds

Jim

[Happy Jim]

Nice job. Hope you did not get to high off the fumes. Reading the POR15 COSH seems you need full mask and ventilation.
I see you have diagonal reinforced inner end Lower Control Arms for extra stiffness.

Smoothrite for me, nice and easy to apply and not too stinky! And yep LCA’s are beefed up nicely.

[jon1d]

Hi Jim,

What plate thickness did you use for LCA'a for strengthening?

I will be dropping rear end and checking end floats while it is out. Well happy with steering and front end brakes and suspension refurb. Never been so tight and positive. I went with standard bushes and not poly.

[Happy Jim]

Hi Jim,

What plate thickness did you use for LCA'a for strengthening?

I will be dropping rear end and checking end floats while it is out. Well happy with steering and front end brakes and suspension refurb. Never been so tight and positive. I went with standard bushes and not poly.

3mm painted (so probs 2mm plate at a guess).

I changed my front bushes out for poly years ago.....can’t say I noticed a difference either way!

Cheers

Jim

[justinb]

Finally sorted my front and rear toe this weekend.

The rear required swapping a 5 thou for a 7 thou shim on the offside to get the overall 1.5mm toe in. To be fair, I do reference Simon Rudmans site frequently as he detailed so much of his build. I found the laser light projecting from rear to front on a piece of angle clamped across the top of the front suspension was the easiest way to do it once you confirm the axle is centred.

Then sorted the front out, which although each front wheel was toeing in by 1.5mm in relation to each other, when compare to the chassis centre line meant that they were off a bit. After marking where they should be on the angle clamped over the rear in relation to the centre line, it was an easy task adjusting the track rod so that the laser point lined up over the target point on the angle.

Just got a trashed back now from doing the rear and leaning over!

Jim - did you use a late model xjs rear end or just swap hubs and discs? I ask as I used the late model xjs with outboard handbrake too and am looking at where to route the cables properly. The diff had some extension parts on it to locate the cables but am considering doing something else.

Also, was the overall track any differernt? I reckon mine is someting like 3mm wider each side than the series 2 axle I have laying around. Any thoughts?

Justin

[GDCobra]

Jim - did you use a late model xjs rear end or just swap hubs and discs? I ask as I used the late model xjs with outboard handbrake too and am looking at where to route the cables properly. The diff had some extension parts on it to locate the cables but am considering doing something else.


Justin

I modified my S3 XJ6 axle with driveshafts and uprights from (I think) an XJ40 or possibly X300, kept inboard discs origainally for handbrake. Width remaind same.
Just recently converted h'brake to outboard using levers from XJS which attach to lower arm inner pivot then there are some brackets which fit to the locations where calipers were previously attached bought new cables to run from the arms/brackets to the h'brake 'drum' and all seems good (not had it MOT's yet)

[Happy Jim]

Jim - did you use a late model xjs rear end or just swap hubs and discs? I ask as I used the late model xjs with outboard handbrake too and am looking at where to route the cables properly. The diff had some extension parts on it to locate the cables but am considering doing something else.

Also, was the overall track any differernt? I reckon mine is someting like 3mm wider each side than the series 2 axle I have laying around. Any thoughts?

Justin

I’ve used half shafts and hubs from an XJ40, remainder is XJ6 S3. Overall track was the same once But had to have a spacer on the inner end of the half shaft (which is actually the XJ6 disk with the outside cut off).

Re the handbrake cable, I couldn’t find any of the late model XJS handbrake cable arms so made a very crude (but effective) holder for the inner end of the cables (length of angle iron above & in front of the diff). If you dream up something swanky....shout and I’ll steal

[justinb]

Thanks Jim and GDCobra,

Maybe i've been overthinking this.....

I've got the brackets which attach to the diff and the lever arms and the longer fulcrum pins. I wasnt sure I could the lever arms to fit as they might foul the top of chassis. It does mean it'll have to come apart again.....

I'll try and upload some images of what I have. 20201208_111755.jpg20201208_111855.jpg20201208_111820.jpg