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Anyone experience wear on the rear upper control arms? Took a look under my rear suspension because it's started tramlining badly. Found one rear tire that was bald, so tires will be my place to start.
However, on the rear upper control arms, the inner bushing (closer to rear seat) is a rubber compliance bushing, the outer bushing is a solid type (nylon ball) bushing. The ball joints and outer bushing are fine--boots are still sealed, no play that I could distinguish while prying.
The inner bushing on the left side of the vehicle seemed to have a ton of play in it, though the bushing was not broken. I could pry and watch the rotor move > 1/8" and clearly see how it would affect my alignment as it moved while driving. The bushing on the right rear side also had play, but less than the left side.
I have no idea if this is normal--these are rubbing bushings with holes through them, they are designed to move. But how much I don't know. I know I can buy Ford rear upper arms and just replace them, but if they aren't broken I don't see a reason to throw away money. Anyone experience this or can comment on the amount of play that's acceptable?
Got the new upper control arms in the rear, that certainly fixed the issue! The driver's side compliance bushing was so badly worn I'm surprised I could even stay on the road. Replacing that side alone made the car feel like it did when it had 30k miles on it!
Some notes on the rear replacement:
1. The brake hose goes through the middle of the control arm, so you have to remove the hydraulic line from the caliper, replace the crush washers, and bleed the systems. The service manual made no mention of this, so cost me a lot of extra time running around looking for parts. Also took this opportunity to flush the entire brake system, as it's been just over 2 years since the last flush.
2. The rear height sensors attach to the upper arm with a plastic mounting clip/clamp. It's tied together using a plastic zip-tie. Don't worry, you can cut the old zip tie and feed a fresh one through the loop to secure the sensor just like the factory.
3. There is no way to possibly torque the bushings while the wheel is installed. Even at the factory it is just not possible. The way I did it was to first loosen the ball joint on the original arm. Let it pop up to its natural height (it's slightly springy due to the bushing). Measured from the wheel arch down. Installed the new arm in the same location, then torqued. Finally, installed the ball joint to the knuckle.
4. All bolts on the upper arm are 18 mm. The rear are a nightmare to access. I was able to get it done with a combination of open end wrench, breaker bar, and 3/8" drive sockets with articulating joints.
Bought the Ford (Lincoln LS) control arms from Gaudin Ford for around $160 each off eBay. "Genuine Motorcraft" with "Jaguar" cast into the metal
Part numbers 6W4Z5500AB and 6W4Z5500AA:
Original arm with taper freed so I could measure the installed height:
New arm installed and brake line bleeding:
Close-up of the compliance bushing. Actually has 2 cutouts in the rubber (at the 3 o'clock and 9 o'clock positions). Easy to see why this wears out so quickly. The old one was soft and mushy, let the arm move around over 3/8" in all directions. New one feels nearly solid. Definitely a wear item!
These rubber, (sometimes called Silentbloc) bushes are a bit like the roll-bar bushes, the hole through the middle gradually gets bigger and bigger, and the rubber starts to break up, with cracks running through it that destroy the resilience of the bush..
If you can move the brake rotor that much, I'd say replace the upper arms. Have you checked the lowers ?
If you don't spend it on suspension parts, you'll spend it on tyres !
These rubber, (sometimes called Silentbloc) bushes are a bit like the roll-bar bushes, the hole through the middle gradually gets bigger and bigger, and the rubber starts to break up, with cracks running through it that destroy the resilience of the bush..
If you can move the brake rotor that much, I'd say replace the upper arms. Have you checked the lowers ?
If you don't spend it on suspension parts, you'll spend it on tyres !
Yes, it's looking like uppers are due to be changed. At least those are reasonably priced.
Lower bushings have been done this past summer, at least the two nylon ball style that are available aftermarket. I don't believe there's a source for the Silentbloc bushing on those? But I'm not seeing any significant play when prying on the lower bushing.
Surprisingly tire wear has been good, it's just that they have worn out (down to 1/32 tread).
Got the new upper control arms in the rear, that certainly fixed the issue! The driver's side compliance bushing was so badly worn I'm surprised I could even stay on the road. Replacing that side alone made the car feel like it did when it had 30k miles on it!
Some notes on the rear replacement:
1. The brake hose goes through the middle of the control arm, so you have to remove the hydraulic line from the caliper, replace the crush washers, and bleed the systems. The service manual made no mention of this, so cost me a lot of extra time running around looking for parts. Also took this opportunity to flush the entire brake system, as it's been just over 2 years since the last flush.
2. The rear height sensors attach to the upper arm with a plastic mounting clip/clamp. It's tied together using a plastic zip-tie. Don't worry, you can cut the old zip tie and feed a fresh one through the loop to secure the sensor just like the factory.
3. There is no way to possibly torque the bushings while the wheel is installed. Even at the factory it is just not possible. The way I did it was to first loosen the ball joint on the original arm. Let it pop up to its natural height (it's slightly springy due to the bushing). Measured from the wheel arch down. Installed the new arm in the same location, then torqued. Finally, installed the ball joint to the knuckle.
4. All bolts on the upper arm are 18 mm. The rear are a nightmare to access. I was able to get it done with a combination of open end wrench, breaker bar, and 3/8" drive sockets with articulating joints.
Bought the Ford (Lincoln LS) control arms from Gaudin Ford for around $160 each off eBay. "Genuine Motorcraft" with "Jaguar" cast into the metal
Part numbers 6W4Z5500AB and 6W4Z5500AA:
Original arm with taper freed so I could measure the installed height:
New arm installed and brake line bleeding:
Close-up of the compliance bushing. Actually has 2 cutouts in the rubber (at the 3 o'clock and 9 o'clock positions). Easy to see why this wears out so quickly. The old one was soft and mushy, let the arm move around over 3/8" in all directions. New one feels nearly solid. Definitely a wear item!
Thanks for posting these excellent photos. Who has been chewing on that brake disc !!
I think you can get a Powerflex bush for the Silentbloc-type bushes, but not sure. My local independent told me the later lower wishbones have two Silentblocs now and only one nylon ball-type bush. It gives longer life apparently.
Thank you for your excellent description and pictures, with part numbers no less!! I am a new member and I am totally impressed with the quality of the conversations on almost any subject dealing with the mechanical side of my 2004 XJ8. I've spent my entire weekend on this forum just surfing.
However, I am confused by the second picture, which doesn't seem to be a picture of 6W4Z5500AB or AA as it has a break, with what appear to be some kind of rubber shielding, in the crossmember. What am I missing?
I have 147k on my car and I plan to keep it another 100k if I can. As preventative maintenance, I would like to replace as many of the bushings as possible, but replacing all of the contro arms to accomplish that would be considerably more expensive. What do you think of me just replacing the bushings? If you think it's a good idea, can you refer me to womehere I can get the specs or part numbers on the bushings? None of my manuals have part numbers.
Thanks again for your post.
Dan
2004 XJ8
1989 560SL
1983 911SC
Last edited by Dan.B; 03-20-2016 at 07:35 PM.
Reason: Pardon me, I meant the 3rd picture of the new install.
Thank you for your excellent description and pictures, with part numbers no less!! I am a new member and I am totally impressed with the quality of the conversations on almost any subject dealing with the mechanical side of my 2004 XJ8. I've spent my entire weekend on this forum just surfing.
However, I am confused by the second picture, which doesn't seem to be a picture of 6W4Z5500AB or AA as it has a break, with what appear to be some kind of rubber shielding, in the crossmember. What am I missing?
I have 147k on my car and I plan to keep it another 100k if I can. As preventative maintenance, I would like to replace as many of the bushings as possible, but replacing all of the contro arms to accomplish that would be considerably more expensive. What do you think of me just replacing the bushings? If you think it's a good idea, can you refer me to womehere I can get the specs or part numbers on the bushings? None of my manuals have part numbers.
Thanks again for your post.
Dan
2004 XJ8
1989 560SL
1983 911SC
2nd picture is of passenger side, 3rd is on driver side. Same part and process, just mirror images. I'm guessing you're looking at the height sensor that clips onto the arm?
I don't think anyone has ever found a source for bushings on the upper control arms. And since the ball joints are also part of that, for $150 each it makes sense to just replace the whole unit. the lower bushings are available, and that is much more economical than an entire $500-700 control arm.
That approach makes sense to me. I'll take your advice.
The part of the picture on the new install I was referring to was the short length connecting the two "arms". It looks like it has been cut through with two black sleeves on the ends where it was cut. I see the sensor that is connected on the long arm on the right. It's not important; I'm sure I'm seeing something that isn't there.
My local independent told me the later lower wishbones have two Silentblocs now and only one nylon ball-type bush. It gives longer life apparently.
Oh, how recent was that? I've just had a quick look at the photos that I took the new rear lower arms before they were fitted 18 months ago and they have one soft bush and two ball type bushes.
I'd post the pics if I knew how to easily get them from my 'phone (remember cameras ?) to my laptop !
I think the easiest way is to email it to yourself from the phone. It's really quick and you don't have to worry about establishing a link between your phone and computer.
Oh, how recent was that? I've just had a quick look at the photos that I took the new rear lower arms before they were fitted 18 months ago and they have one soft bush and two ball type bushes.
I'm only going on what I was told, I haven't actually seen the latest part that is fitted to the XF that has just left production, The current XF (mostly aluminium now) has a different suspension as I understand it, but I may be wrong.
Yes, that looks to be them. It's up to you, as the new arms are only slightly more and you get a new ball joint as well. Was worth it to me to just swap the arm without having to run to the shop to have them pressed in and out.
With all this bush swapping business, it is always a toss-up between buying a new part with the bushes already in, and swapping bushes over on the existing part. Problem if you're not DIYing is the labour to press-out and press-in the bushes. Jaguar X350 suspension components have come down in price over the years with lots of stuff on the internet, so in many cases it is not worth it.
Problem with top wishbones both front and rear is the ball joint at the apex. These are not available separately so if re-using the arm with new trunnion bushes, this ball joint needs to be in apple-pie order. Steel-aluminium in close proximity can mean the housing corrodes away, so be very careful !
Does anyone have a source or part numbers for the rear lower control arm bushings? I'm replacing the upper control arms and I would like to have my mechanic replace the lower bushings as preventative maintenance (147k on the car) at the same time.
Thanks much for the part numbers especially! If you just type in Jaguar XJ8 upper control arms on eBay, you get the Jaguar price, if you use the part number, you get the Ford price or about $100 off each side!
I removed both of my rear lower control arms, thinking I would press out the old bushings and press in the new ones I bought through eBay. However, the control arm bushing kit I got on loan from a parts store ended up not fitting. So now my car is up on jacks with the control arms out.
My next best option is to take them to my local mechanic shop to do the bushing presses next work day. Anyone have any DIY advice on how to get these bushings out and in without having to take it to a shop?
BTW, I noticed a lot of wear on the sway bar links, so I've got a couple on order to swap them out too. Any advice on doing those?
Rear sway bar links are not expensive if you buy right, (on the 'net), and are a simple "unbolt and remove old link, replace and secure new link", sort of job.
Problem with replacing the wishbone bushes is that accurately made mandrels to push the old bushes out and the new ones in are essential.MY local independent has them and can replace the bushes, but the cost of complete wishbones is now such that it is a toss-up between just swapping arms and removing the arms, swapping bushes, and replacing. Labour has to be charged to swap out the bushes. Of course as a DIY proposition it is a no-brainer if the right tools are available.
02-08-2016, 11:15 AM
rear upper control arm compliance bushing
