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Between 2000 and 2002, Jaguar S types and Ford Thunderbirds, Lincoln LS's, and a few other models used the same upper front control arms. In 2003 Jaguar changed thier set up, but it appears Ford did not.
Does any one have a numeric or tangible result of using prefacelift control arms on a post facelift car?
I have a pair of 03 STR's which both need upper control arms. I bought 2 sets of chinese arms off ebay a few days ago. I new there was a difference but the seller insisted they would fit 2000-2008 S Types. I am attaching photos of the difference between the right arm which came off my 03 STR and the arm which should fit an 00-02 S Type. Although they do physically fit and are very similar, I am concerned about adverse effects. I have read a thread on the forum with a claim that the castor was about -2 degrees. I dont think this is possible. If you look at the photo, the new control arm has the ball joint further back, which would tend to make the castor more positive. Thoughts?
Has anyone done this and what is the outcome? How far off was the suspension after alignment?
Thanks
New versus old, they appear the same.
upon closer inspection, a slight difference
Slightly better view of the offset
Last edited by benpearce2013; 11-18-2016 at 10:24 PM.
Reason: Forgot to add photos
After changing the right and left sides, I measured both old sets compared to the new set. Both pre facelift upper arms have the ball joint shifted approximately .75" rearwards when compaired to the post facelift arms. I did a few basic calculations and came up with a new castor angle of 8 degrees as compared to 6 degrees before.
I have no concerns about the strength, the rough geometry is the same and the machining/casting looks good. On Monday I will hardness test the Chinese arms versus my Jag originals to get a numerical comparison.
I am actually happy about increasing the castor angle, I do lots of highway driving in Illinois and don't do much for high speed cornering.
Sorry for the lateness, I have been very busy. I Rockwell hardness tested the old and new arms. The alloy is comparable in strength between the new Chinese arms and the old original Jag arms. The bushings and ball joints seemed to be well made. Below is a link to the particular arms I purchased.
I had them both aligned a few days ago and as expected, the castor is much more positive. The change in castor also changed the toe, to if you do this swap, you will need an alignment. Final numbers are 7.9 and 8.0 percent castor with everything else being in the "green" zone. Personally I am happy with this, as an increase in castor will increase stability on the highway.
In summation: the 2000-2002 S Type front upper control arms are different from the 2003-2008 arms. The old style arms are much cheaper because they fit Lincoln LS's and other ford products. Using these, you save a lot of $ but expect your wheel castor to change and save money in your budget for an alignement (I paid 50$ per car with a coupon).
While I was rereading this something occurred to me. If the rear arms have a similar difference in geometry, could they be interchanged to help rectify the camber issue that occurs when lowering springs are used? Since all modern Jaguars share suspension components it would potentially be possible to swap the upper and/or lower arms from any of them to get back within alignment spec. Not exactly sure how to narrow the field down to the best possible donors though. Just a random thought...
Sorry for the lateness, I have been very busy. I Rockwell hardness tested the old and new arms. The alloy is comparable in strength between the new Chinese arms and the old original Jag arms. The bushings and ball joints seemed to be well made. Below is a link to the particular arms I purchased.
I had them both aligned a few days ago and as expected, the castor is much more positive. The change in castor also changed the toe, to if you do this swap, you will need an alignment. Final numbers are 7.9 and 8.0 percent castor with everything else being in the "green" zone. Personally I am happy with this, as an increase in castor will increase stability on the highway.
In summation: the 2000-2002 S Type front upper control arms are different from the 2003-2008 arms. The old style arms are much cheaper because they fit Lincoln LS's and other ford products. Using these, you save a lot of $ but expect your wheel castor to change and save money in your budget for an alignement (I paid 50$ per car with a coupon).
From experience using the pre upgraded arms on a post upgrade car does lead to a reduction in handling performance. I had my upper A arms replace by an indie and they used the pre-upgrade arms by mistake. The handling was noticeably poorer, with way too much self centering force and very a strange front end feel when pushed hard into a corner. When I looked at the issue, it wasn't just the castor that was way out of spec but the thrust line from the lower ball joint through the steering knuckle to the top ball joint was way off. The indie replaced the A arms with the correct ones and all is well now. You only show the horizontal plane in your pictures but the later A arms are quite different in the vertical plane with the ball joint thrust angle very different. The correct Loemforder A arms were $170 a piece, chump change if you own an S-Type...
11-18-2016, 08:33 PM
Pre vs. Post facelift Upper Front Control Arms
