Hey guys, I have been looking for a poly front sub-frame bushing option on the x308. Has anyone come across such a thing or would anyone happen to have the dimensions of an uninstalled bushing that they could share. I'm exploring the idea of making bushings myself. Cheers

 

Do you want bushings for the wishbones or bushings for the subframe? The subframe could only have two bushings, as the V mounts would be hard to replicate in PU. The wishbones I think can be done with Powerflex bushes.

 

Circular subframe bushings rear of the v mount.

 

The bushings can be cast yourself and there are threads on this and the material comes in different densities effecting your ride the XJR having harder . If you look at the different suppliers one offers a small quart size to be able to experiment with .

 

Any links to the threads on casting subframe bushings? I have searched to no avail.

 

Might find something in the X300 area as they are about the same

 

I wonder if a solid mount would be a better option, Alloy?

 

Thats my next thought. I have access to a lathe and was going to experiment with a bar of aluminum. However the poly video above looks pretty cool.

 

IMHO solid mounts would destroy the NVH of the cars, Jaguar went to a lot of trouble to design the mounts.

 

Depends on your tastes. for an NA xj the bushings are just fine IMO. If your a more spirited driver with an XJR I think the car can greatly benefit from a more positive feel. If you've ever driven one of these cars with worn/torn subframe bushings, you can feel the entire front of the car shift under breaking or have steering play. It gets nearly dangerous; so longevity is a plus here as well. Alloy in the rear with the standard rubber v mount would most likely be a good compromise.

 

Most certainly a very worrying feel. Do it at 125 mph and you'll think the car is falling apart!

The only problem I see, is adding a lot more stress to the solid bolt but also to the mounting points of the frame AND the subframe. The rubber allowed it to flexibel to a specified degree. A solid aluminium or steel bush will prevent that and the results could be really nasty... But that is a COULD.

I have been told, that the racing X308s/X300s/X27s/... have their subframes welded in place to only allow movement of the wishbones and not the subframe.

 

Solid mounting subframes is very common in the Audi world as it transforms the steering feel and handing. I would only do it if you can convert the front mounts to solid too, otherwise you are just going to stress and fracture the mounting points in the body shell.

I would also like a poly solution, i changed all four mounts a year ago and already the two front v-blocks have separated and need replaced.

 

That's odd ? Typically good for 100k ... did you use OE?

 

The V blocks take a lot of stress. If you lift the car they are taking a good portion of weight. I just replace v blocks and have my old ones sitting by for R and D. I agree that solid rear mounting point would take the brunt of the stress which makes me lean towards poly. Also leaving the front mount oe allows for that mount to absorb small amounts of vibration and road surface. Being that the rear mount would then be more solid might keep the v mount from experiencing lateral movement potential stopping it from tearing as often. In theory anyway. Anyhow if anyone happens to have dimensions of the OD of that subframe mount it would be greatly appreciated. Keeps my car off my lift while I try and R&D a mount.

 

Couldn't tell you the brand, sourced them from britishparts.co.uk. Guess where i wont be buying them from next time?

 

If the vee's were the $25 priced ones they were probably URO, that particular part by that manufacturer is known to have longevity issues, bad rubber compound, rubber melting or cracking, etc. If they were in the $90-100 each they were probably OEM which should last a long time.

Another thing to keep in mind with making poly rear bushes is that they act as a centering part as well, not just handling forces perpendicular to the mounting bolt, so you need to make sure the inner mounting tube is centered depth-wise and will not slide around inside of the casting.

 

It seems most of the aftermarket EURO stuff is from India ... When it started to show up years ago in the MB community everybody loved the prices but the parts did not hold up. With the number of rubber items in the Jaguar suspension setup .. this has been a topic of discussion my whole life. I remember in the early 80's replacing the mounts for my last 70's XJS w/nylon ... and instantly regretting it.

It's a pay now or pay later situation .. The OE stuff does last typically 80-100k

 

Reading this thread made me think about making poly bushings for the front shock mounts. Last year I had bought new shock mounts for the regular non cats dampers, of course I bought the cheap 25$ uro ones since I was going to throw them on the press and take off the bushings and switch them over to my original shock mounts with cats dampers. Sadly they're already rattling. I'm thinking I could get some clay I have to make the mold of the original bushings I saved and fill the molds to make new poly ones. Has anyone already done this with any luck?

 

The recommended molding material is Puritan found at the local ceramic supply shop or maybe at the craft store