Not sure I'm calling them correctly (front suspension mounts). But here are a couple of pics of mine. These pics were taken while car was on jackstands. They are obviously well deteriorated. I have a spare pair of new ones. How easy are they to change? What do I risk not changing them right away? What symptoms might they be creating?

 

OOPS.

Front cradle V Mounts.

VERY common, Mongrel job if a V12, not so bad with 1/2 an engine.

GENUINE Metalstik ONLY here. All the aftermarket have failed withing weeks. I get from SNG in the UK, Simon is the man.

C45666 which is now MNC2360AA

 

Bill,
As you have to suspend the engine off the cross member to do this, I Highly recommend a Harbor Fright engine support bar:

This Marvelous invention mounts on the hood rails, is almost Infinitely adjustable, has a capacity of around 1000 pounds. Here it is supporting the entire engine while the front suspension was over on the bench getting refurbished and the rest of the car is up on jack stands.

It may not be on the display floor at your local HF store, I had to specifically ask for one which they dragged out of the back somewhere. But then, our local stores are a bit limited in showroom space.

Mine was $75-80. YMMV
(';')

 

What kinds of problems is this creating?

 

You already have the problem now you need to fix it.

You Must get the weight of the car off the cross member. That means you need to jack up the car as you have done,

support the engine with the support bar (almost a clone of the one illustrated in the Blue Book; ROM),

put a trolley jack under the cross member to support it so you can loosen the bolts to those bushings,
lower the cross member slowly and gradually, just enough to remove and replace said bushings.

Then reverse this procedure for reassembly.

This will not take you a mere 15 minutes but there's nothing hard magical about it, only a bit of tedium.

If I've forgotten a step (been about 5 years since I did this) I'm sure someone will jump in to fill in the blanks.

I wish you success.
(';')

 

Lack of front end stability at least.

IF these V-bushings don't have a through-bolt (like Chevy motor mounts of the same era), it's possible the whole cross member could part ways with the rest of the car under certain circumstances, such as lofting the car over a RR crossing or what we used to call a WHEE hill, and you could be left with Zero control as brake lines could be broken leaving you with NO stopping function and of course no steering.

Of course, this is Worst Case Scenario.
(';')

 

Well... another job ahead of me! By the time I'm done with this car ( who am I kidding; I'll never be done), I will be a better equipped garage than the local service station down the street. Now it's a engine support bar. Thank God for Harbor Freight!

Thank you all for your sage advice and support.

 

I just read the Service Manual under SUSPENSION UNIT MOUNTING - REAR 60.35.07 and it says nothing about having to support the engine in that writeup. So... people who have done that job before (replacing the two rear mounts), is it necessary for me to support engine. I'm smart enough to know the manual is not always correct. LnrB - did you support engine to do some other job at the same time?

 

Yes, actually, the cross member was over on the bench getting a complete refurbishment, leaving nothing to support the engine.

For sure if you follow the directions you have here you will soon find out if I was wrong.
As I mentioned it's 5 years since I did this.
(';')

 

Hi,
It's been ALOT longer since I worked on the front suspension but I think these bushings can be changed without the engine support bar. Just keep in mind the jack ( with a little help from the front suspension bushings & rear trans mount ) is holding up the engine & suspension assembly while you are under / around it changing the bushings, so it has to bee lowered VERY carefully and just enough to change the bushings. I'm not sure if completely lowering / removing the jack will cause damage but I would not want to be the one to find out.

Good luck, stay safe,
Brian

 

Here you go.

I wrote this back in 2011, and found it this morning.

It includes the front "6 shots", just because.

It is related the the XJS V12, but, as I said, the 6cyl is the same, and a tad easier without a steer cooler.

 

OMG Grant! You are the best! Great writeup! I have been accumulating new "undercarriage" parts for years now and have a pair of V mounts. I have no idea if they are the genuine Metalstik or not, so I best start researching through SNG Barratt to get them. I only want to do this job once! Unlike most of the other jobs I do on the car that get my attention a few times before they are done correctly.

 

Just saw on SNG Barratt's site - MNC2360AA - $109.63 EACH! I'll go with the current ones I have in inventory and take my chances. I knew I was doing the right thing by accumulating parts over the years.

 

OUCH.

Beer O'clock me thinks, damn.

 

Bill, SNG also offers an aftermarket mount for $63 (MHC2360AA*).
Dave

 

I've been watchjng a lot of You tube guys messing with various critters.

In many, elderly fork lifts or back hoes are used for engine support or replacement.

Seems as a great idea for jaguar folks as well.

Carl,

 

Yes, I did see the cheaper ones, but was recommended that I go with the genuine ones. And since I already have a pair of mounts that I picked up years ago, I'll go with them. But, I have no clue what they are, original or clone replacement. Guess over the next few months or years, all will reveal. I'll do the job tomorrow. Had golf tournament today in 95d heat with 85% humidity. Wiped me out!

 

Couldn't help myself, started the job. Got all the nuts and bolts off, but the engine/front suspension assembly does not lower enough to clear that lower 9/16" stud to clear. I need another 1/4" or so. Even with a couple of big screwdrivers in there trying to compress the broken mounts, I need just a little bit more. Wish I did this job last weekend when I had the rear transmission mount out! Guess I'll remove the trans rear mount again tomorrow. I'm hope that will give me enough lowering.

 

Bugga. The V12 drops nicely, good to see they are good for something.

I would:

Release the shocker top mounts, just in case, you dont want to bend a shocker.
Loosed the engine mount top nuts, or the lower, whichever is easier to access on a 6.

You did slacken the huge nuts on the front cradle round mounts??????

 

Changed mine recently. The original 9/16 studs are about 1/4" shorter than the new replacement parts! Originals have a low profile 9/16 nyloc nut which I could not obtain any more.