Front axle differences XJ/XJ-S
#1
![Default](/forum/images/icons/icon1.gif)
Hey everybody...
As a few threads lately had been started regarding the front axles of the XJ-S/XJS rotting through and people saying that the axles are the same (I was amongst them
), I have found some differences...
Firstly:
all XJ subframes (XJ6, XJ12, XJ Series I, II or III) are the same as the XJ-S/XJS. No matter if V12, 3.6l or 4.0l. The subframes are the same.
BUT the rest is slightly different. I've been comparing parts to see what I can/should keep and what I have to part with. This axle is from a series II XJ6.
The upper wishbones have a different shape and have some different shiming compared to the XJ-S. The camber is also a good bit different (as far as I can tell, the XJ-S has more camber in the front as the upper wishbone sits closer to the subframe than the XJ-S wishbone dones - as they are mounted on the inside of the subframe, thicker spacers = more camber). Left is XJ-S, right is XJ6 series II. You can see the wishbone shape is more tapered to the middle unlike the straight XJ-S wishbone halves...
![Front axle differences XJ/XJ-S-dsc_0026-2-.jpg](https://www.jaguarforums.com/forum/attachments/xjs-x27-32/136401d1474553581t-front-axle-differences-xj-xj-s-dsc_0026-2-.jpg)
The uprights are very similiar (in my case they lack the ABS hole and toothed wheel on the hub) but have a different hub sealing (compared to my 1989 uprights) so be careful with that!
Last but not least, the lower splash guard for the brake disc (the little plate) is rounded off rather than squared.
![Front axle differences XJ/XJ-S-dsc_0024-2-.jpg](https://www.jaguarforums.com/forum/attachments/xjs-x27-32/136402d1474553581t-front-axle-differences-xj-xj-s-dsc_0024-2-.jpg)
Otherwise everything seems the same. The lower spring pans are the same. The lower wishbones look the same too... So if you plan on simply exchanging your axle for one from an XJ (older, newer) make sure you keep these facts in mind! Less camber can result in a less sporty ride. And if you have ABS you will want one from 1988/1989 onwards...
As a few threads lately had been started regarding the front axles of the XJ-S/XJS rotting through and people saying that the axles are the same (I was amongst them
![Big Grin](https://www.jaguarforums.com/forum/images/smilies/biggrin.gif)
Firstly:
all XJ subframes (XJ6, XJ12, XJ Series I, II or III) are the same as the XJ-S/XJS. No matter if V12, 3.6l or 4.0l. The subframes are the same.
BUT the rest is slightly different. I've been comparing parts to see what I can/should keep and what I have to part with. This axle is from a series II XJ6.
The upper wishbones have a different shape and have some different shiming compared to the XJ-S. The camber is also a good bit different (as far as I can tell, the XJ-S has more camber in the front as the upper wishbone sits closer to the subframe than the XJ-S wishbone dones - as they are mounted on the inside of the subframe, thicker spacers = more camber). Left is XJ-S, right is XJ6 series II. You can see the wishbone shape is more tapered to the middle unlike the straight XJ-S wishbone halves...
![Front axle differences XJ/XJ-S-dsc_0026-2-.jpg](https://www.jaguarforums.com/forum/attachments/xjs-x27-32/136401d1474553581t-front-axle-differences-xj-xj-s-dsc_0026-2-.jpg)
The uprights are very similiar (in my case they lack the ABS hole and toothed wheel on the hub) but have a different hub sealing (compared to my 1989 uprights) so be careful with that!
Last but not least, the lower splash guard for the brake disc (the little plate) is rounded off rather than squared.
![Front axle differences XJ/XJ-S-dsc_0024-2-.jpg](https://www.jaguarforums.com/forum/attachments/xjs-x27-32/136402d1474553581t-front-axle-differences-xj-xj-s-dsc_0024-2-.jpg)
Otherwise everything seems the same. The lower spring pans are the same. The lower wishbones look the same too... So if you plan on simply exchanging your axle for one from an XJ (older, newer) make sure you keep these facts in mind! Less camber can result in a less sporty ride. And if you have ABS you will want one from 1988/1989 onwards...
#2
![Default](/forum/images/icons/icon1.gif)
Jaguar put some more anti-dive and anti squat geometry into the XJS front suspension, I believe, than was in the saloons at the time the car was being developed, also the car was lowered compared with the saloons, and certain aspects of its handling made sharper compared too, I think. Maybe the differences you show are to do with one or both of those aspects.
Greg
Greg
The following users liked this post:
Daim (09-23-2016)
#3
![Default](/forum/images/icons/icon1.gif)
Agreed, the cradle/subframes are identical.
A huge mistake I see way too many times is the camber shimming. The thickness of the shims fitted to the FRONT bolt, MUST be the same thickness as the shim fitted to the REAR bolt. This maintains the top and bottom pivot pins in a parallel plane.
Caster is set by relocating the fitted shims out AT the top balljoint, whilst maintaining the same number of shims in total. This caster system carried right through to the X300.
MANY wheel aligners are LAZY, and attempt to set caster/camber using the top bolts, using different shim thickness front to rear. Now, this is fine on many generic cars, GM. Ford, etc, but NOT the Jaguar system. When set this way, the owners find the top and bottom (less so) bushes wear out quite quickly. It is all in the angle of the dangle.
All of mine were wrong at purchase, and once sorted, and top and bottom bushes replaced, I never visited that area again.
A huge mistake I see way too many times is the camber shimming. The thickness of the shims fitted to the FRONT bolt, MUST be the same thickness as the shim fitted to the REAR bolt. This maintains the top and bottom pivot pins in a parallel plane.
Caster is set by relocating the fitted shims out AT the top balljoint, whilst maintaining the same number of shims in total. This caster system carried right through to the X300.
MANY wheel aligners are LAZY, and attempt to set caster/camber using the top bolts, using different shim thickness front to rear. Now, this is fine on many generic cars, GM. Ford, etc, but NOT the Jaguar system. When set this way, the owners find the top and bottom (less so) bushes wear out quite quickly. It is all in the angle of the dangle.
All of mine were wrong at purchase, and once sorted, and top and bottom bushes replaced, I never visited that area again.
The following 4 users liked this post by Grant Francis:
#4
The following users liked this post:
Grant Francis (09-23-2016)
The following 2 users liked this post by Paul_59:
Daim (09-23-2016),
someguywithajag (01-21-2021)
#6
#7
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,894
Received 10,952 Likes
on
7,196 Posts
![Default](/forum/images/icons/icon1.gif)
Jaguar put some more anti-dive and anti squat geometry into the XJS front suspension, I believe, than was in the saloons at the time the car was being developed, also the car was lowered compared with the saloons, and certain aspects of its handling made sharper compared too, I think. Maybe the differences you show are to do with one or both of those aspects.
Greg
Greg
I think you are right.
Another tidbit to help future sedan-XJS parts swappers:
The Series III Sedans were made with two different specification upper control arms....so be very careful about mixing and matching. The change is subtle...not something you'd easily spot on simple visual inspection.
I'm sure the info is in the archives but I recall the change being 1983-ish and involving the 6 cylinder cars only. The upper arms were changed to the same part number as used on the V12 cars. The V12 cars used the same upper arms all along.
I think this was related to the anti-dive geometry as mentioned
Anyhow, I may have the details a bit wrong but the important thing is to be aware that a change was made
Cheers
DD
The following 2 users liked this post by Doug:
Grant Francis (09-24-2016),
Greg in France (09-24-2016)
Trending Topics
#8
![Default](/forum/images/icons/icon1.gif)
And many are so set in their ways they don't want to know.
I normally have the local put the car on the rig and l then take the printout home and move the shims/adjust where nessessary. The guy got a bit cut first time l said l didn't want him to actually do the alignment. You need to watch them on steering rack with pipe wrenches too.
I normally have the local put the car on the rig and l then take the printout home and move the shims/adjust where nessessary. The guy got a bit cut first time l said l didn't want him to actually do the alignment. You need to watch them on steering rack with pipe wrenches too.
The following 2 users liked this post by baxtor:
Daim (09-24-2016),
Grant Francis (09-24-2016)
#9
![Default](/forum/images/icons/icon1.gif)
And many are so set in their ways they don't want to know.
I normally have the local put the car on the rig and l then take the printout home and move the shims/adjust where nessessary. The guy got a bit cut first time l said l didn't want him to actually do the alignment. You need to watch them on steering rack with pipe wrenches too.
I normally have the local put the car on the rig and l then take the printout home and move the shims/adjust where nessessary. The guy got a bit cut first time l said l didn't want him to actually do the alignment. You need to watch them on steering rack with pipe wrenches too.
Then how many think you are totally crazy when you ask to ensure they use the centreing tool to centre the rack. All they want to do is remove the steering wheel and respline it, DUH.
The following users liked this post:
orangeblossom (09-24-2016)
#10
![Default](/forum/images/icons/icon1.gif)
![Frown](https://www.jaguarforums.com/forum/images/smilies/frown.gif)
My poor C30 had some brand new leather seats and the result was, after an alognment, that the leather was badly cracked when the tw*t put the clamp...
Thread
Thread Starter
Forum
Replies
Last Post
powerhouse
XK / XKR ( X150 )
7
08-30-2016 01:23 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)