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Every version of the 308 uses the same truss. It has noting to do with the anti-roll bar. The CATS electronic shocks have a soft and a hard setting and all 4 shocks adjust together. They do not provide any anti-roll control.
Not trying to argue with you, but how do you explain no truss in the pics Vector and xjr2014_de have posted? Both have sway bars but no trusses.
A standard antisway bar setup is a passive suspension which is only linked to the suspension components to keep the tires from picking up from body roll ...as to where the CATS is an adaptive suspension (not to be confused with and active suspension which is independent for each wheel) that controls the active movement of the suspension in sequence with the body with a firmer shock activation, squaring the car on the road. When I engage mine at a stop, I literally can see and feel the whole car engage, like its locking down. You get less body roll (similar to a antisway bar) when you firm the shocks, just at a different point and in this case with the assist of the firmness of the body of the automobile. It allows the driver to dictate a soft or firm ride as to the sway bar only allowing one option.
just to end this discussion: This so called "truss" is the differential strut to achieve better stability compared to the monostrut solution which the X300 models used to have (https://www.jaguarforums.com/forum/x...t-x300-143384/).
The differential strut is ALWAYS fitted, either with comfort or sport bushings (dependent on the shocks). It's definitely there, even if an anti roll bar is fitted.
Concerning the sway bar pictures, you hardly can see the mounting points and the differential strut itself since the mounting plate is different/bigger and the camera angle is inconvenient.
From a different angle, you see them clearly!
The X308 "truss" does not replace the anti sway bar
Originally Posted by rocklandjag
Every version of the 308 uses the same truss. It has noting to do with the anti-roll bar. The CATS electronic shocks have a soft and a hard setting and all 4 shocks adjust together. They do not provide any anti-roll control.
Correct, two separate issues/parts, and a bit more info on the X308 "mono tube" or "truss" here:
This "truss" was standard on all X308s, regardless if an XJR, VDP or XJ8.
Some of us with X300s have retrofitted the X308 "truss" to replace the individual "dog bones" that were used on the X300 to stiffen up the rear suspension. It is said that some X300s received the X308 "truss" under warantee if the owner complained of rear suspension/stability issues. We've also heard that the manual XJR6 had the "truss" but not certain.
Hey grandell, was yours a short wheel base you changed that out on? I'm wondering if the VDP (like mine) didn't come with sway bar for comfort purposes or was it a per customer order?
If you look close you can see it .... it sits behind. Most of it is blocked in th picture
Now that some other pics have been posted I can definitely see it on top, but it isn't engineered the same or for the same purpose it appears? As in grandell's pic, his truss is like mine, behind the differential supporting it from the bottom rear, giving more rigidity supporting the diff. The one mounted on top appears to just be holding it in place.
rocklandjag, I see what your saying about the truss, but I can't agree on the shocks in sport mode not helping prevent roll. They may not stop the roll, but they do help against it. I can definitely agree if I were to take mine to the track, I'd make it a point to add a anti roll bar. But for as it is, its real solid in street corners.
Hey grandell, was yours a short wheel base you changed that out on? I'm wondering if the VDP (like mine) didn't come with sway bar for comfort purposes or was it a per customer order?
As far as I know all XJR's are regular (short) wheelbase, and it was only the US VDP's and rest-of-world Daimler SuperV8's that were both supercharged and LWB.
XJR's would have all had anti-roll bars, but I'm not so certain about the VDP's and SuperV8's. I can't remember if they had the standard 'touring' or 'sports' suspension
Now that some other pics have been posted I can definitely see it on top, but it isn't engineered the same or for the same purpose it appears? As in grandell's pic, his truss is like mine, behind the differential supporting it from the bottom rear, giving more rigidity supporting the diff. The one mounted on top appears to just be holding it in place.
rocklandjag, I see what your saying about the truss, but I can't agree on the shocks in sport mode not helping prevent roll. They may not stop the roll, but they do help against it. I can definitely agree if I were to take mine to the track, I'd make it a point to add a anti roll bar. But for as it is, its real solid in street corners.
What is confusing -- there are two sets of angled supports. You can't see the upper differential supports in the first set.
Now that some other pics have been posted I can definitely see it on top, but it isn't engineered the same or for the same purpose it appears? As in grandell's pic, his truss is like mine, behind the differential supporting it from the bottom rear, giving more rigidity supporting the diff. The one mounted on top appears to just be holding it in place.
rocklandjag, I see what your saying about the truss, but I can't agree on the shocks in sport mode not helping prevent roll. They may not stop the roll, but they do help against it. I can definitely agree if I were to take mine to the track, I'd make it a point to add a anti roll bar. But for as it is, its real solid in street corners.
The differential brace or "truss" is not designed to manage "sway", but instead to hold and brace the differential and thus also properly locate the rear suspension wishbones.
On the X300 this "truss" was two separate struts (dog bones) which still allowed the rear differential to slightly twist under acceleration and deceleration forces, as well as suspension travel. The X308 "truss" solved this issue by triangulating what were the two independent links into one "truss" unit.
The "truss" is actually called the "Bushed Differential Strut" and was available in "comfort" (MNC3713AA) or "sport" (MJA3713AD) bushed for the XJR or sport models.
You can see the mechanical difference here:
The rear anti-sway bar controls the vertical movement of both rear suspension wishbones to flatten the car when cornering by linking both wishbones together via the anti-sway bar.
Thus the "truss" and ant-sway bars serve different functions.
Can the "truss" affect handling? Yes it does. Does/can it compliment the anti-sway bar and other suspension components as part of the system? Yep. But the "truss" primary job is not as an anti-sway device, just as the anti-sway bar's job isn't to securely locate the differential.
All X308s came from the factory with this new and improved (over the X300) "truss". As I mentioned above, we think some X300s have the "truss" fitted as a warantee issue later and the manual transmission XJR6 are thought to have had the "truss".
All X308 and X300 XJRs (and X308 sports) should have come from the factory with a rear anti-sway bar. And to fit & support the anti-sway bar the car must have the proper "wishbone tie" which BTW the one in the eBay auction above appears to be missing and instead has the "wishbone tie" for a car not equipped with the anti-sway bar. The correct "wishbone tie" part number for the anti-sway bar equipped models is MNC2855BA/BD
Hope that clears up the discussion about the "truss".
It still doesn't answer the mystery of why the XJR in the eBay auction seems to be unusual. I'm sure someone could ask, but since I'm not trying to buy the car I don't want to bother the seller.... so I haven't
.
Last edited by al_roethlisberger; 03-12-2016 at 02:55 PM.
Hey al_roethlisberger, I see you've been in a similar discussion before https://www.jaguarforums.com/forum/x...iiiiny-124192/ and posts 5 and 10 pretty much lay out the need or not of a sway bar. Oh those sneaky Jag engineers....
Also to help clear up some things, there were changes on the '03 versus previous years. The XJR was the top model, not the VDP and the suspensions availability was different.
....'03 '00
Do you guys see the difference on the rear of what Vector posted? If you don't have the sway bar, you have the truss carrier like I have on my VDP. It literally is a truss like on a commercial building. This mounts to the body on the wide parts of it and down to the differential where it is attached. Thus replacing the old style sway bar.
I used yellow on the second pic to see it easier.
Thanks for posting this. I have a 2003 Jaguar XJ8 4.0 Executive (Japanese re-import back into the UK) and there is no anti-roll bar or drop links etc. Just a tie bar as you show in your picture. I was getting worried that someone had messed with the car in Japan !!
03-11-2016, 07:34 AM
The X308 "truss" does not replace the anti sway bar
