Rear spring and u-joint clearance

[MontanaDiver]

Out for a drive and at 45 miles per hour, I developed a intermittent scraping noise. Nursed it home, jacked up the rear and placed it on jack stands on the body. No noise. Moved the jack stands to the outside hubs to place weight back on the springs and approximate ride height. Again no noise. Crawled underneath and found the rub marks on the inside axle joint of the axle shaft on the left (drivers) side. Corresponding rub marks on the forward spring of the shock. Approximately 1/4” clearance between axle shaft at joint and spring after lifting Jag to place on stands. Right side clearance is 1/2”. Tried to move things around and get suspension to settle while still in jack stands at both hubs. No movement at the driveshaft and at the wheels. Circlips on u-joints are all in place. Slight movement at the top of the shock. Put it back on the ground and drove it 1/4 mile and the interference is back.

Starting to think about what is wrong. First thought is the wishbone bearing(s) is bad and allows the hub to move. If this is the case, if I disconnect the shocks at the bottom can I verify the bearings are functioning or does anyone have a better idea about where to look. I bought 4 Boge shocks this spring to use this winter as a service item. Slight wheel hop on wet pavement under heavy throttle. I can replace the shocks as a test. I have an appointment at my alignment shop, but they have never seen a Jaguar IRS.

Any thoughts guys?

Dennis

[abowie]

Take the shock out and check the bush at the top and bottom, and that the spring is seater properly and is centred.

When you reinstall it, rotate it 180 degrees.

[MontanaDiver]

Thank you for the confirmation. I didn’t look on right side, but left side upper shocks are installed with the nut on the outside. I will replace all 4 shocks this week.

Dennis

[mgcjag]

Hi Dennis.....so something has changed to start the scrapeing......is your car sitting lower at the rear?....tyres, tyre pressure?....As Andrew says check shock bushes etc and check jor UJ play.....Steve

[MarekH]

Take a look to see what the undamaged side looks like and figure out why the bad side is asymmetric to the good side.

gap.png (222.95 KiB) Viewed 1578 times

Also, assuming the second photo is looking upwards, it looks like you may have a collet missing - it may be the angle, but I don't understand what the gap circled is. The shock is pretty dangerous in this state as it holds a huge amount of stored energy - enough to take your face off.

See arrowed photo .

kind regards
Marek

[MontanaDiver]

As always thanks for your insight. Going to remove and replace all shocks today. I will check the circled part. I think it is the end of the spring. My assumption and hope is the top bushing has failed allowing the shock to move. Everything else appears to have no slack movement, u-joints, wishbone and radius arm. I will check again after removing shocks. I took lots of pictures and will take more to see if anything has changed. Tires are at 32 pounds from last road trip. Height appears even on both sides. I will measure it today.

Dennis

[MontanaDiver]

Jacked the car back up with jack stands under the wishbones. Lifted the body to release the weight on the shocks and the left front shock is broken at the mount.

Can the shocks be removed without dropping the IRS. I cannot see the rear shock nut. If I remove the wheels, is everything accessible?

Starting to think I will send this one out instead of crawling around on the concrete.

Dennis

[angelw]

Dennis Wrote:

Can the shocks be removed without dropping the IRS. I cannot see the rear shock nut. If I remove the wheels, is everything accessible?

Hello Dennis,
R & R of the shock absorbed/spring assembly is a relatively easy exercise and doesn't require removal of the IRS. To replace the shock absorbed in the assembly will require a spring compressor.

Regards,

Bill