What is wrong and what needs to be replaced?
The sound happened when i hit a small bump, like u going on and off driveway.
Or when i lift the left side of the vehicle, the right side will make a sound.

 

Check all shock absorber rubbers. Check all ball joints for play with a pry bar. Check all subframe rubbers. Check idler bushes/bearings. Look for shiny spots or play in anything. LHS is the same. Get help from a friend & listen carefully for approximate area of the noise.

Replace as necessary.

 

The most common cause of "clunking" when going over bumps in MK1 and Mk2 cars is a failure of a front suspension mount which is item 4 in Glyn's picture. They fail in shear mode
I don't remember how many I have replaced but it would be well over a dozen. It is so common that I keep a couple of spares on hand.
If it is not one of the mounts then follow Glyn's instructions ref shock absorbers, ball joints etc.
Cheers.

 

It could also just be the sway bar bushings (74 in the picture). Modern cars can produce the same sound and it almost feels like it is coming from the chassis. I have found that it is more pronounced when you hit a small bump with one wheel. That causes the sway bar to flex and if the bushings are worn, the bar will move around and make the clunking sound. Its not a serious issue but the suspension mounts are. Check those first.

 

Generally on a modern car when you get that clunking over bumps it is the drop links that attach the sway bar or anti roll bar to the suspension. 77 in Glyns diagram. These are difficult to check for any movement as they are under tension. I have not had the same problem on my S Type but then again I am not putting the same miles on her as I do my modern run about.
If you cannot see or feel any movement yourself there are two options. First take it to a garage who do annual auto checks. In the UK they are called MOT checks. The garage should have a simulator or rattle plate which gyrates the front suspension whilst it is on a ramp and they can see any movement from under the car. If you want to do it yourself then it is a matter of trial and error. Start by replacing the oldest and cheapest suspension part first whether this is the drop links or rubber sway bar bushes or ball joints. Each time you replace a part take the car out and see if the noise is still there. If you do a drop link on one side do the same to the opposite side. You might find you replace all the suspension bushes and ball joints but you feel a difference in ride and stability once done.

 

Hi,
Thanks for the help.
I see there is a front suspension repair kit listed on SNG.
Would be include everything that can possibiliy make this sound to replace?

 

I take a quick look at the suspension. I can tell my sway bar link bushing is completely gone. Sway bar mounting bushing is bascially gone. Are they possible gonna make the clunk?

 

The sway bar to chassis rail bushing is one of the faster wearing parts of rubber and will definitely make clunking noises. Fortunately, it's easy to replace.

 

As stated very easy to replace both bushes. Two bolts on each bush and the bush caps will come away. The new rubber bushes slide on to the bar and you bolt the caps up tight. Try to do both at the same time by jacking the car up so both front wheels are off the ground. If you try and do one side at a time, jacking up just one side of the car each time you will have a lot of tension on the sway bar and it will be difficult to get the bush caps back on so the bolts meet the threads.

 

Wise advice from cdg, Peter, Bill & Cass.

 

Thanks.
I take a second look at the bushing. The sway bar to body one is completely gone. I can move the sway bar by hand. The sway bar to link is gone also. Not sure how long ago it gone, do i need to replace the link as well?

 

Apart from the bushes to the chassis rail, there are rubber bushes at each end of the drop links. Any that are degraded or missing are better replaced. As for the links themselves, if they look OK, there's no need to swap them. They can get bent, especially if the rubber bump and rebound stops (that limit the up and down motion of the wishbones) are missing. If you replace the links, check the dimensions of the new against the old before you start - they may need to be adjusted.

Incidentally, polyurethane bushes are available. They should last longer than rubber and give a little more stiffness. Personally, I've no experience of them. Perhaps someone else has?

 

They squeak unless kept lubricated & add harshness to the ride. I'm not a fan of poly bushes unless racing.

 

Glyn, Forgive me, but would you recommend a lubricant?

 

Any grease containing Potassium Borate. I don't push my company on forums but it's called Chevron, Texaco or Caltex Ultra Duty Grease EP. NLGI 1 or 2 ~ we used 2 ~ never to touch again. All the majors make great products but this is a bit of an in house thing. We will sell the additive now via our additive company Oronite. Borate is our development.

The only thing that shut up the poly-bushes on my friend's rear sway bar with poly-bushes on his Jeep Grand Cherokee Laredo Blue Pearl Edition. (also known as black pearl edition in some markets). Made in Graz, Austria with Merc 5 cylinder diesel, leather, fancy audio system you name it. Now sold & replaced. I should have bought it. 120,000 Km's, Dealer maintained. In perfect condition & he gave it away for peanuts by SA standards GBP 3500. My problem is no place to keep it. I only have a 2 car garage. I guess I could have parked it outdoors but it would be a pity ~ it was immaculate.

 

Gee Glyn, you could have parked the Jeep at my place with 9 undercover car spots. I have 3 unused. You would have been welcome to visit.
Re the poly bushes, I suspect there may be a lot of variation in manufacturing standards, possibly between countries.
I recently saw a Mk2 which was imported from England and supposedly had a complete rebuild by a reputable organisation 5 years ago.
All of the poly bushes in the front end were decayed and falling apart (crumbling) requiring a complete rebuild.
I put Australian made poly bushes in the rack and pinion steering box mounting in my S3 XJ6 about 15 years ago and they are still good.
I have used poly bushes in non jaguar cars (Fords and Holdens) and they have worked OK but have not observed them over a long term.

 

We replaced the old rubber bushes in my series 3 Daimler in 1993. They were still good when we swapped the steering rack last year. Of course, there's nominally no movement in the rack application, which must help. Also, I imagine poly bushes is an area where many are tempted to save up and buy on price rather than quality. I believe the better suppliers provide grease with their wishbone bushes. Apart from avoiding squeaks, it ensures chemical compatibility with the bush material. Certainly for the steering rack, poly bushes are a worthwhile upgrade for feel and longevity and improving the turning circle!

 

Yes. There is good & bad available in anything. These came from a US supplier & their squeaking was driving him nuts. He bought them in Minneapolis close to Donaldson HQ from a tuning shop. There was no sign of deterioration. Just noisy.