Since my 1st Jaguar acquisition earlier this year, I got to know my 2003 XK8 coupe pretty well.
I’ve only found minor imperfections that I have addressed myself… UNTIL now I’m afraid.
I found major displacement of the bushing bolt
for the lower right control arm (rearward).
The wear appears to me as though it has destroyed the area adjoining the mounting hole on the aluminum front sub-frame.
Please don’t say I need another subframe!
S

 

It's called an ADJUSTING BOLT (JZB 100085) and it is for CAMBER ADJUSTMENT.

Jaguar also issued an ECCENTRIC SHANK BOLT (JZB 100086 - Refer to Dealer Support for fitment info)

 

See Pictures…
My 2003 XK8 has a damage on the front sub-frame where the lower wishbone is attached.
Is there a known repair/mod for this type of damage to Aluminum?
Or is replacement my only Reasonable option?
What the #@%! is Aluminum doing at




stressed joints?
Thanks for your advice as Always!

 

I wander if you can drill it out round and then insert a stainless steel sleeve. It will probably corrode inside eventually but the steel should be harder and shouldn't wear like the aluminium has. It's either that or replace the whole subframe. It could probably be welded up and re-drilled again although wouldn't the same thing happen again? I guess this was caused by the subframe bolt not being tight enough so with the play it beat the aluminium out of shape. I feel like I should check mine now, is it easy to get to?

 

I'm not sure if it's just the photo, but that bolt doesn't look right. There's no sign of the shank, only the thread going into the hole - or have you pushed the bolt partly out?

As Kuddlesworth said, you can likely get it drilled out and bushed, although I don't know if you'll get proper access without removing the subframe. You may also find signs of distress at the other end given the amount of 'slop' that the bolt is showing.

Easy enough to get at to check the bolts are torqued up properly - this should be done with the weight of the car on four wheels.

 

I'm with Michael on this...

Also, one of the bolts (can't tell in the photo is this is the front or rear of the two lower control arm) is eccentric and allows for setting alignment. I believe that one of the holes that accepts the bolt for the lower control arms in the subframe is designed to accept a bolt that isn't true round... Check this idea,,, brain fog, and I can't remember exactly how this works and would look...

 

Why are you not continuing the other thread you started????????????????
https://www.jaguarforums.com/forum/x...killer-254050/

 

Thanks all you Leapers! Sorry for my Jag Lag! I’m All In on this car, so I took the passenger side suspension out.
Pictures now fully show damage to the mounts of the subframe.
No cracks are visible… Only vibrational reaming/chipping is evident to the rear mounts only.
The forward lower control arm mount on the subframe appears in good shape. So no other residual damage/wear is evident.(Thanks for mentioning Michaelh!)

But here I feel stuck! The damage to the rearmost mount looks very bad to me.
I’m not sure how this type of damage can be done without major (Perhaps Unseen?) stress damage to the area around the holes…
Note these damaged bushing mounts aren’t very thick either.
The forward most hole damage could be from sawing action of the threaded-area…however,
the Rearmost hole (larger & contoured) was malformed by a smooth-shafted bolt, not reamed by sawing vibrations.
I wonder if this is a real safety issue or am I overreacting to an easy fix & strong aluminum?

Tomorrow I am calling a professional mobile welder to come give me advice, options, & estimates ASAP.
I will update you with that and any other progress expeditiously!

My other option looks good too, but more in-depth. A full subframe replacement.
Currently, a used subframe is available quickly and affordably. It doesn’t seem too hard according to other jag brothers.
But It would take me weeks to finish the job.. so not ideal at Christmas time.
No matter…My Lady will roll again!

Kuddlesworth, I will be asking the welder about inserts as an option. And yes..I highly recommend checking these bolts!
They’re so easy to get to with an open wrench and a socket. I included a picture showing the location by the oil filter. Thanks!

Michealh, I did have the bolt partially out in that picture.. The new pix show it All! Thanks for the tip about tightening on the ground. I just saw a video talking about why to do that.👍

JayJagJay, I heard about the eccentric bolt. I am including the Tapered ended bolt in the pictures. It appears perfectly round, although tapered.

 

Right up near/just below the bolt HEAD (with it's eccentric-ity) is supposed to fit in that hole. You can see it in the picture. It's the flared area just under the bolt head.

I think the person that worked in it before you put the bolt in the wrong way,,, which (if my memory serves me right) would have left SOME of the bolt head (placed on the wrong side) sticking out. Noticably out... The tolerances for the part of the subframe that receives the bolt, the diameter is too small if reversed.

I would push/run the bolt out and see what happens (what it feeeeeeels like) when placed the other way...

 

Motorcarman, I'm not questioning your authority but I have a question. So this JBZ100085 + 86 are eccentrics that can be added to replace the existing bolts? My '03 has no such eccentrics anywhere in the front suspension (I thought this odd of a higher end car) to adjust the camber. So this might be a retro-fit?? Tell me more. ThanksIA, TM

 

I'd be wary of welding on an aluminium subframe as it may have been heat-treated. That subject is touched on here in a discussion about repairing a similar problem with the upper arm pivot pin holes:
https://www.jaguarforums.com/forum/x...53/#post137066

Probably better to go with bushing, although if you have easy and inexpensive access to a subframe it will reduce your downtime. If you do go the latter route, check where the pivot pin for the upper control arm locates as that is the more usual place for wear to occur. Either way, subframe out is a good time to inspect the motor and vee mounts 'while you're in there' (you will get used to that with these cars )

The bolt you've pictured looks like the one for the front control arm bush? - which isn't eccentric.

@Jay - the rear bolt was in the correct way round as I distinctly remember the track rod having to be moved out of the way to get it out

 

The contoured bolt fits nicely in the rearmost hole. It is the only hole large enough for the large bolt head, so it must be right.

 

I know aluminum rods for lower temp torch repairs (propane,etc..) are popular.
I wonder if the low temp rods results in much weaker patching.
‘This is a troubling question… the welder wants to come today, and I could be on the road in hours.
I’m afraid if I ask the welder, he’ll tell me “weld! It!” no matter the heat issue.
Speaking as a novice, I’m feeling that carefully welding in steel as a bolt sleeve sounds best so far.
Thanks for the heads up!

 

Ahhhh, man yeah... That looks rough. Actually, both holes do. I was wrong.

I swapped my subframe for another due to enlarged UPPERs in the upper control arm. If you have one ah them engine support bars and a ball joint separator,,, it's actually pretty easy. 4 bolts for the steering wrack... Get a new subframe, ask for CLOSE UP photos of the important parts, and keep it moving... Lol, Michael is AWLAYS right! Haha

 

Totally agree: the bolt comes out past the tie rod towards the rear of the car. I just didn't see the eccentricity in the pic

That sucks: it must have been jiggling around for a while. I had all this apart earlier in the year to do the lower bushings. I'll be out with the torque wrench if it ever stops

Good luck with the repair.

 

I wish...

 

Jaguar’s Bottomline is literally on the bottom line in Yellow & Blue!
This page shows pre-2003 subframe. Later 2003 is enclosed & doesn’t show the internal support structure.
I assume the no-weld/repair subframe rule applies to all Xk8’s.
(Does anyone know if they have identical connection points? Interchangeably possible?)
Thanks

 

Thanks. I knew I'd read that somewhere but didn't want to state something without attributing the source.

I suspect that you will be fine on interchangeability, other than, possibly, from 2003 on there are some 'with HID sensor mounting holes', although I doubt that is significant.
Heritage gives a series of part # supersessions, and tallies with the JEPC:



and


this one has the holes for the HID mounting

I hope that makes sense.

 

Are you in the states? eBay is great and there is a seller called "https://www.ebay.com/str/playgroundpar]playground par"[/url] I think is there name that has a pretty impressive inventory. The subframes are not so so expensive as one might think...

 

U.S. EBay= Used Subframe will be here tomorrow. Only $300 w/ 2-day shipping
New control arm upper/lower bushings $100
Shocks and upper mounts add $350
balljoints & tie rods seem good.

Must get engine support bar before drop frame…$80 wasted..never use again
Then inspect engine mounts..OR SHOULD I JUST REPLACE ENGINE MOUNTS? (2003 XK w/ 34,000 miles)
Are there any other parts/special tools I’m likely to need under there?

So waiting on parts & planning stage in progress.
Thanks for the heads up on this.
I’d hate to try this without you guys on my side!