The foam in my front strut mounts have obviously crumbled as evidenced by crumbly stuff in the top of the mount and wheel arch to wheel center distances of approx 14.25" drivers side and maybe 14.5" passenger side as compared to the 15.25" I have read they're supposed to be.

I've bought the Welsh Enterprises poly mounts intending to replace myself, but changed my mind and visited a local indy mechanic to ask him how much to do the job using the mounts I'd bought.

He agreed to do it but he insisted the springs need changing as well. The car has done 46k miles and while I can understand how the foam in the mounts would deteriorate over time, I would have thought the springs would be OK at least for another 50k miles if not longer. He told me no, the springs will deteriorate with time not just with mileage and need to be changed and he could tell just by looking at the car. When he was about 10 feet away from the car he said "Yup, the front is at more than 2" low and the springs need to be replaced". He said the sagging front springs are common on this car and he has done about eight XK8 strut mount replacements in the last year and the springs needed changing in every case.

Well, from my measurements it's maybe 1" too low worst case and it seems to me most of that can be explained by the strut mounts. Now, I can understand that the weight of the car over time may cause the springs to sag a little bit, and the added weight of the driver may make the driver's side a little lower still, but I wouldn't have thought the springs needed replacement. In addition, while I can see from searching this forum that some people replace the springs (and other suspension components) along with new mounts, the car mileage is usually on the higher side, and/or they feel they may as well replace everything while they have things apart. There seem to me many cases from the forum where the mounts have been changed (and maybe some bushings) but the springs have been left alone.

So, should I go with this guy and the extra expense of replacing the springs or should I find another indy who will do the mounts only?

 

Paul, I'd just do the shock mou ts and measure to see if you need springs, but then I'd do it myself. Guess you risk double labor charges if I'm wrong but that's my vote. You have low miles on her.

John

 

My local dealer renewed my upper front shock mounts at 75K. 'Not a word about springs.

 

Personally, I think most stock cars look better dropped a little, including the XK8. I'm not into the trophy Jeep look, and the main reason I'm putting off replacing my upper shock mounts is that I don't want to jack the car back up. Look at it as a free lowering kit. It doesn't really have any ill side effects driving it with slightly sagged springs and should ride better than most aftermarket dropped spring kits.

 

I agree. Using the updated Welsh upper spring bushing brought my front end up to level my XK8. Springs were fine at 50k miles. Rich

 

There is a lot of weight on these springs. For example purposes, i have another 2001 car, different brand, with almost the exact same mileage as your xk8, never abused the suspension, normal use on paved roads. Last year suddenly a front spring broke. It is a micro fracture failure with corrosion seeping into the openings. My tech showed me trade journal discussions of how this happens as I was curious. I did everything including what would be shock absorbers on our cars. i did not realize how bad it had become until i did this; like a new car in terms of handling. You should do everything, including the shocks as you might not have ever experienced the car as it was intended. You will be surprised. Also, it would not be nice to have a spring fail after you do all of this work.

As for the look, some MBenz guys think that my car is too high, even though it is at spec. If you look at the original presentation of the car, this is how it was meant to ride and look. In fact when another that was dropped was next to mine, people commented that at my height you could appreciate the lines of the forward section better. Plus it is nice to drive everywhere without the issues of these other cars with their dust-buster (type of vacuum) front ends and factory lowered fronts. A dropped front end on this car will not handle as well as a factory setup without major suspension engineering work.

 

I would bet your springs are fine at this point, but...

Since you are not doing the work yourself I would recommend you do the springs and the shocks at the same time as the upper mount. The additional parts cost would be about $500 but you would avoid nearly that in future labor costs. Plus less down time.

Also would do upper control arm bushings (another $100) since that has to come loose to get at the upper mounts. If you have not done those yet they will likely not survive the disassembly anyway and are probably hard as a rock.

 

Skip the springs. If they have sagged a little you can add a spacer up to 3/8" thick on top of the shock mount without removing the springs. The control arm bushings are a good idea.

 

I wanted to get my springs done but the OEMs were NLA. The place I used was kind of annoying about after market and said my springs were fine (or good enough).

 

The indy mentioned that MBenz's were especially bad on springs and told a similar story about broken ones. He also mentioned water and corrosion as a failure cause.
As a "European car" indy he sees far more MBenz's, so I think he has just extrapolated that experience to Jaguars.
Interestingly, he didn't think the control arm bushings needed replacement.

Given my car is not a daily driver and hasn't been out in the rain or snow much, the mileage is low and I'd like to spread the maintenance expenses out over time, I'll think I'll just stick to replacing the shock mounts. Although ordering the upper control arm bushings seem good idea too.
Thanks for all the opinions given. It's helped a lot.

 

My blue cat is an '01 MY as well. Changed out OE springs at just over 100k.

BTW, the ride height should be 15.75". If you are at 14.25", then you may have other issues as the top mount will only gain you about 3/4". Check the lower shock bushing. These can deteriorate with time (vs. mileage). If bad, the price for the whole shock with bushing is not much more than just the bushings.

+1 on doing the control arm bushings while you're in there.

 

The lower shock bushings are available for about $11 now on ebay.

 

I had a similar experience with my '97. First I replaced the rotten upper shock mounts only for them to melt after a few months (Motorcars Ltd.) Replaced upper mounts again but was still riding low about 1 inch and I couldn't get the camber correct . Finally replaced the springs and all is good. While everything was apart I replaced the shocks and new poly bushes upper and lower. It made a huge difference in ride and I'm not scrapping the nose over every driveway. The entire episode was very frustrating until I finally replaced the springs.