Gents,

I have been working on my newly acquired 01 XJR for a few months now. One item that continues to frustrate me is a front end vibration that feels like bottoming out shocks, bad front sub-frame bushings or failed engine mounts. Had a peek around and looks like although the PO did install new shocks, his mechanic missed out a few parts that might be the causing the issue. Attaching a few pictures, and would sincerely appreciate some guidance on a few questions before I commence buying the replacement parts:

1) Are Bilstein Sport the correct shocks for this vehicle? As reflected in the picture I took, the shocks appear to be KYB, but I see part #6 and #7 missing, not sure about part#9. I suspect this is causing the font end vibration.

2) Should I consider also changing the front springs based on the age of the vehicle?

2) Part#5, shock absorber top mount spring bushing is peeling. I have never quite seen anything like it. Would hate to put a Uro part that rots out so am contemplating ordering from (https://www.britishparts.co.uk/jagua...op-mount-p4607) as the oem part is quite expensive.

Appreciate the input from fellow seasoned members as I am eager to get the vehicle back at 100%.

 

Page 16 , notice the difference between sport and standard for the XJ8 , look for the bushing on the shock lower mount ( item # 9 ) . I can see daylight through mine as X308 is like my X300

 

Have you checked your bearings (1), ball joints (7 & 10) and bushings (all the others)? Your shock tower mount bushing is definitely toast, there are many threads on them here.

 

As stated by Highhorse, should check all those items that are circled. However another item I have come across quite often is the Engine Vee Mounts, #4 that is pictured just above the front subframe picture. These have been quite common on the 308's, and can cause vibrations in front end when going over bumps.


To check these, you can jack up one side of the vehicle, as you are lifting the front off the ground, if you see it start to lower from chasis, they are bad/separated. Another way to check, you can stick a pry bar in there to see if you get any movement, which there should be none.


Engine mounts can also simulate vibration going over bumps if they are failed as well. Easy way to check these is start the engine, place in drive, keeping left foot on brake, using right foot to slightly press accelerator pedal and see if the engine lifts on one side or not. These are another common issue with 308's.

 

Thanks all. Just had new engine mounts put in, on my previous Jag X308 the V mounts were indeed shot so had specifically asked the dealership to check them and they came back with just one of engine mounts was shot on this vehicle. I've also had an independent shop go through the front end and the only item they found was that the PO used cheap rotors and they do cause front end vibration at 55 MPH or whilst braking. My observation of the vibration though is tied more to an item like the front shocks or V mounts. I will start with the shocks and then look into other items such as the V mounts.

 

What mileage has the car done so far? Do you know if and what had been done by the PO?

Testing the upper and lower ball joints with a prybar doesn't work always 100% sure. Two of mine were shot and didn't move a bit when being threatened with a prybar. Now the front end feels much much more composed and direct than ever before. V-mounts and subframe bushings are always a good idea to replace - meanwhile they're turning 17 years ;-)
But I'd go with the easier parts first, like control arm bushings (replacing them eliminated my front end vibration and improved handling a lot), drop links, top plate bushing, anti roll bar bushings etc.
If you want to do the whole lot anyway, then the most easiest way to do so is to drop the entire front subframe and put it on the bench...then you can replace all in one go.

Cheers, Alexander

 

As Alexander states that not all is as it seems, so be sure to double check.
Can you be a bit more descriptive of your vibration? Does it feel like its only in the steering or do you get a seat tickle also? Does it do it during certain speeds or is it constant?
I would like you to review this thread... https://www.jaguarforums.com/forum/x...g-info-188400/ ...its what happened to me recently as I was going through the progressions to find the culprit. I'm definitely not saying any of this is your issue, but reviewing my issues and checking those parts may help.

 

OEM was bilstein shocks - I've read that the KYB's may sometimes have poor longevity, something to keep in mind...

Also look at the front subframe "rearward" bushings - #2 in the picture on the right posted earlier, that go in the very back of the front subframe - I am suspecting mine are worn, and I've been getting some front end vibrations, along with slight shuddering when going over bumps at low speed. Those bushings can be hard to diagnose visually from under the car though, they're somewhat recessed. Already checked the V mounts and engine mounts externally. It's also possible that my shocks are also on their way out... I'll know once I build a spring compressor and brave the cold for this repair, maybe I'll find that I have to do V mounts, etc as well.

 

Autozone has 2 types of spring compressors in there tool load program so it ends up free and also important safe . Found a piece of iron to build a bridge engine lift and the vertical support post can sit inside the engine compartment on the heavy beam situated below that run for and aft , protected by wood . So not a big investment in building materials

https://powerflexusa.com/xj6-x300-x3081994-2002.aspx

There is a different density rating between the SC models and the non - SC models

 

Many thanks all. I am starting with the shocks, and all bushings tied to it plus the front anti roll bar bushings. I dod suspect that my subframe bushings are also shot, but might have to it to a competent shop for that.

@Highhorse: Where in FL are you located and is there a shop you recommend. I am in Clearwater, Tampa Bay area. You have a wealth of knowledge Sir and am sure the shop yu use in quite familiar with the X308.

 

PM sent

 

I grabbed these shock tower mount bushings from Welsh over the summer:

Welsh Enterprises, Inc - Jaguar XJ8 (98-03) Front Suspension Parts - XJ8XJR 98-03 Urethane Upper Shock Mount Bushing Kit

Mine were toast in the '100' and have been quite happy with these. You should consider picking up a set, given the condition of the ones in your XJR!

 

Just a quick update. Installed (F + R) sway bar links and bushings + Bilstein green sport shocks in the front and rear with all new bushings, bolts etc from Britishparts.co.uk. All clunks etc are gone. I do have some pending front end vibration left, but know it is coming from the cheap rotors the PO had installed. Next project is the Brembo brake upgrade and hopefully will get the vibration closed out in full.