Sub Frame Mounts - PieceMeal?
 

Wondering what folks think about this. Any and all aspects.

These 3 cars are killing me and take up lots O my free time. It's summer and I need time for "me" (lol, that's what my girlfriend is saying, haha)... Me! Yeah right.

I was intending on swapping the engine (for like 1 1/2 uears now) out of the the 2002 XK8 for a low mileage engine and in the process doing all mounts. Subframe and motor. I have the PARTS, engine even, but not the time. I know it's past time for the Sub Frame Mounts and it's bugging me that they are the way they are. The jiggle.

For the rear (front) subframe mounts I was wondering if it would be possible to jack up the car supoorting the body, support the engine, loosen the steeting pinch, shockers, roll bar and the rest - then loosen and wiggle out only the rear subframe mounts and replace? How much of the rear of the subframe will hang if I do this and will I be able to get the 4torxs and center bolt and re-move and re-place the mounts this way?

Would the front mounts be accessible this way?

Any suggestions? What say you?
https://cimg9.ibsrv.net/gimg/www.jag...2cb99dbca1.jpg

I took mine out with the engine in place, you'll need to get the steering rack out the way if I remember, they can come out easy enough but the pain was for me working under the car on axle stands. Be careful with bolts stripping and snapping, I only had one go on me which was an easy one to get out but if you search the forum for v or see mounts you'll find out what you need... Mine delaminated and really needed replacement

Good luck

Awesome. Thank you Dann! Really.
If ya remember,,, which stripped or snapped? It always sucks and changes the job. Right now, I'm dealing with a sheared off bolt, a rubber isolator, which screws right into the block on an old Porsche 928. My goodness. It can turn your project for the day into THAT project. Repairing the shear. Any idea on which I should be most careful with? The torx? 8 of them,,, lol. OMG what do I get myself into?

How much will the subframe drop? I'm guessing I will have to loosen it completely remove bolts from motor mounts? Or will the Sub tip forward and back? And, how did you remove the front rounds or did ya?

Ok. I got stuff. But am toooo worn out to describe fully. But I'll be back, lol - OMG!

https://cimg4.ibsrv.net/gimg/www.jag...1764592129.jpg
That surface rust aint nuthin nice... Plenty O room for the removing, though... Stripped toes are the worst and to be expected on the underside of a 20yo jaguar. Smh.

Hey

Looks like your going through it ok!!! It was one of the torx that went.. and i also snapped the tool i was using.. I put copperease on them when they went back.. Be careful not to overtighten when going back in.. be gentle.. dont overtighten and risk right at the end having a thread strip...

Hey Dann. Good morning.
REAR MOUNTS TO BEGIN... I'LL GIVE A PLAY BY PLAY hoping it will help someone down the line...

QUICK QUESTION, Dann: If you did this and remember- do the FRONT SF mounts push up or down on removal? I couldn't tell while I was in there....

Honestly, its not a bad job at all. I think I could do both rear SFmounts in about 4hours, maybe less, if EVERYTHING went right. But yes. The damn torx bolts. Sometimes I wonder just what the hell Jaguar is thinking...? Bolt heads they must KNOW are going to be exposed to everything,,, fasteners on the UNDER side of a vehicle are going to be exposed to,,, need to NOT be 40 torx bolts. Anyone that knows anything about labor would know this. 3 of the 8 stripped out right off. Soft and brittle like crumbly cake.

So, I jacked her up using the subframe to begin. Nice and high. Placed jack stands. Then went in to see which of the bolts I could access attempting to spin the 6 torx that i could access first AND the main center bolt just to see whereby stood.

A Jaguar thing,,, the steering arms needed to be detached (maybe?) at the rack to allow right access to the center SFmount bolt. After, used a short socket to get to the center bolts properly, an extension and a 1/2 ratchet. Center bolts came right out,,, shweeeeew!

Again, a Jaguar thing, one of the torx bolts on either side was completely obstructed by the lower control arm bushing mounting points (dumb engineering). I removed this LARGE control arm bolt and used a pry bar to move the arm knuckle down and outward out of the way. Used the bolt, feeding it into the hole left, to keep it out of the way.

Got to the bolts and the one on the passenger AND drivers side stripped, as did one of the torx on the PS outer bolt slots. Stopped and took a breath. Once I got a sense of where I was with the mount fastener situation I decided to proceed.

- SO, I removed strut bolts, leaving one for good measure on both sides.

- Next I removed all four bolts from the steering rack leaving it to "dangle". Still in there pretty sturdy. Control arms still undone at rack.

- Loosened bit did not full remove the bolts at the front subframe mounts and it's supporting brackets... Leaving all bolts in place with a fair amount of threading. I want to just tip the subframe at the rear.

- Placed Jack stands across the front body cross member just under the rad. Placing tires under the car just under the pilar, around where the door meets the fender for safety...

- Slowly lowerd the jack at the subframe to see how much movement I was going to git! Looked good. Jacked it back up a little at the subframe and removed 2 remaining strut bolts which had bottomed out on the first lowering. After, struts pulled thru and hung free.

- With that there was plenty of room to remove the mounts. It seems the new mounts will just drop right in.

The drivers side worked with drilling the head of the torx bolt. The passenger side, not so well. I could NOT and CANNOT get what remains on ONE of the torx bolt thru the hole in the subframe... It is painfully hung up/stuck in there. I will have to drill out a larger hole to remove it. I don't like it.

On replacement I will be using https://www.mcmaster.com/standard-hex-head-screws]threaded bolts from these folks .[/url] Hardened HEX M8x1.25 40mm course threaded bolt and a lock washer. YES to the antisieze... Ridiculous what Jag did here... These cars sure are a mix of beautiful UGLY!

I have the front SFmounts,,, motor mounts, and top shock mounts on hand. After I get thru the disaster of this damn bolt I will decide if I will continue and replace them all..

Thanks for your time, help and attention, Dann

someone very recently posted how they did their front sub mounts.. It looked easier than doing the rears.. a lot has to come out the way, as you found out.. to get bolts removed... How did you know they needed doing? Were they delaminating? Thats how I found out on the annual test.. I am now wondering if I need to change my motor mounts... Have you looked at your top mounts yet? for the front shocks? I replaced mine a year and a bit ago.. just out of warranty of course, I noticed there was a height difference on the front, soooo... back to taking the shocks out.. then checked the new pattern top mounts and they were not good.. so I did what a guy did on here and made my own nylon ones... and also poly bushed the centre where the shock goes through.. Quite a job..

heres some fun reading for you.. as your in the states you can buy a poly bush kit for the top mounts.. They are less compliant but last longer.. But careful.. I think some poly bushes are not as good as others...

https://www.jaguarforums.com/forum/x...t-62654/page2/

You are correct - some poly shock mount kits are indeed substandard and break down in just a year or two. The general advice here is to stick with the Welsh Enterprises kit and you will be happy for quite some time....

Oh yeah... I replaced the shock mounts while I was in there. It turned out to be great fun, too, lol... 😣 That's if I'm getting you. I will look at the link. I replaced these. (See below)

I dunno... I could just tell I think. The front end seemed "wobbly" for lack of a better word. And yes, most of the rubber was broken off the aluminum frame and they were pretty much flat. I can't really tell yet with the fronts but I have them and want to and will do them. And like you, yes, the motor mounts as well. I think if I lower the sub at the front it will be not so bad.

It's amazing how loosening things up here and there a little, allowing things to hang, rest on a jack, pivot can give you SO MUCH more room to get at stuff around the engine compartment.... Makes the inaccessible accessible...

https://cimg5.ibsrv.net/gimg/www.jag...2a95da9303.jpg

This is what mine looked like before I replaced them. Felt like I was driving on ice.

https://i.postimg.cc/BvZDD2hS/knock-knock.jpg

https://i.postimg.cc/fRNYzGm0/knock-knock-2.jpg

You might be as well dropping the front subframe to see what welding may need doing under there. Have a read Click Me

😨😨😨😨😨😨
I'm shakingin ME boots!

How does one, unsee, something?

Its something you cannot see unless you remove that bit of suspension. Feels like a different car since those were removed. If I had known there was a polybush version of that fitting I would have put those on instead.

Hey, good morning Frank.

Honestly, especially around the front passenger side and here and there, I saw some pretty clear evidence similar what you found. I don't know what much I can do about it as I have no way of getting into my machine as deeply. I would like to. No lift and none of the right equipment, welding etc... So really,,, I'm shaking in ME boots. I'll have to figure something out.

In what you saw of that job, will supporting the engine, removing bottom bolts from the motor mounts, loosening the rear mounts, the sway links, shocks and such - allow the subframe to tip forward enough to push the front mounts down and out? Would like to know what I'm getting into before going in, if you know what i mean...?

Thanks for the photos. I intend on studying them much more closely today! Import info contained in all that work y'all did. Photos speak 1000 words. Deep thanks! Really!

Thanks for the compliments.

Got to be honest with you its the sort of job that should really be done in a garage workshop rather than on a family driveway. I am sure it can be done the way you suggest but I have a feeling you will get half way through and say to yourself........... I wish I had never started this. You always seem to 'find' and electrical connection that you had forgotten about or find more under there than you bargained for. I had no idea my floor was that bad, I should have done though as its a very common problem with our cars.

One thing for me I was not expecting were the CATs, catalytic converters. One had a welded seam that was starting to go. While the engine and subframe are out etc. Same with the engine mounts. There was nothing left of them. More a case of removing the pieces rather than the whole mounts. On it went.

I am sure you are more than capable of doing it yourself but the question is......... do you really want to? Good luck whatever you decide.

Oh you are welcome.

It's not that I want to do it, I need to. And, although I so feel a little overwhelmed by a job once I really get into it, when this leads to that and shows me yet another "thing" that I have deal with - I am doing this for fun, a pass time, a hobby, etc. I usually remember that after, on the highway with the top-down - headed to the beach 😊

I intend to get under there tomorrow Saturday... Start to figure out what it would really take. Engine supported im feeling like ill be able to let it hang in the front so I can do my thing.

Thanks for you great post and info share!

Still - very open to suggestions

Still with a CLUNK
 

So, I've replaced the rear sub mounts, shock tower mounts and the lower shock mounts... Still dealing with a noticable clunk coming from the front end. Seems mostly from the pass side,,, but I also seem to hear something eminating from the driver's.

I fear it's the pin holes where the steel upper wishbone control arm pin meets aluminum sub frame,,, and what it will take is a steel sleeve in the old,,, or paying for a new subframe and sleeeving it before installing the whole thing (a hell of a lot of work and some $$$)... What a stupid stupid design!!!

Maybe before all that, front subframe mounts to see if that solves it... Another tough job.

Any CLUNK hunting advise?

Rubber mounts beneath shocks?

Hi, yeah, thanks...

Replacing lower shock mounts was a part of this job. Ended up a good thing... I don't know what this is... I suspect play in the ridiculously designed subframe and pin set up for the upper control arm(s)... I could be wrong tho

The thing about 'clunks' is that its obviously two bits of metal banging together. It might be an idea to look for marks as much as the noise?

I assume that you have tried bouncing the car whist its parked? Dont know if yours has CAT suspension but if it has it may be better to 'bounce' when the engine is running so the suspension is active. I could never get mine to 'bounce' as its too stiff but a friend helped me 'bounce' on each corner in turn and it turned out to be left rear suspension.

I am rather surprised too that you still have the clunk when you have done all the bushes, especially the front wishbone. That would have been my first choice. Rubber mallet and tapping along the exhaust? Loose handbrake mountings?

When does it do it? Hitting a pothole? On accelerating/de-accelerating? Turning corners? Uphill, downhill?

I really empathise with you. I had a dam 'ping' noise for months. Sounded like someone hitting a bell every so often. Turned out to be the metal cap over the rear suspension put back on wrong.
This is how mine was fixed. If you play the video, sound on, you can hear the dam 'ping' that drove me nuts. Click me to jump to problem

Hope you find it. Good luck!:)

Hi Frank...

Unfortunately bouncing the car does not produce the noise at all... Nothing on accelerating or slowing. Not corners or most any other time,,,, other than small to medium sized imperfections in the road. It's this low tone almost soft-ish sounding (and very regular) clunk. Going down the road at this point I KNOW what kind of raid condition will cause it. It's the strangest thing.

BUT I have a theory... I completely removed the bolt from the center or main lower control arms (the one that holds the lower ball joint) on both sides to do both the shock upper and lower mounts and the rear subframe mounts. Made everything much easier and "movable". I just looked at torque specs for all things front suspension and DOUBT I got anywhere close to this high of torquing things back down. Am fairly sure that my clunk is coming from the large bush connecting the lower main control arm to the subframe. I have grab my torx wrench, jack her up,,, and put the wrench on everything I messed around with, take her for a spin SO I can find out just how wrong my theory is, lol...

More, they are hard to see when she is all together (and kinda when not) but I need to do a real checking on the poly sway bar links I (mis) installed way way back when. Maybe the shifted around during the loosing process of replacing the rear subframe mounts...?

Anyways, here's the specs.