can anyone help. when setting off from a stand still or from a slow roll if i press the gas i get a thud from the rear end

 

thats on a 89 xjs 5.3 by the way

 

Hi Pete, moving this on over to the XJS section, you know the guys will help you.

A tip for the future, include the Model + Year in the title of your post, makes life easier for everyone, including your good self.

 

Sounds like something might have come loose, so best to get it up on a lift and inspect it.

 

I forget to mention the rear subframe mounts. These can fail and the rear subframe is then totally loose. Also check the two radius arm mounts that project forward from the suspension uprights, and bolt onto the lower-rear of the sills.

 

also check the exhaust pipe mounts.. one was knocking around back there for a couple hundred miles until it was found to be the passenger side exhaust.

 

As above, plus whilst on the hoist/lift remove the central tie plate and check carefully the 4 bolts (2 on each side) that secure the inner pivot shaft brackets to the diff casing. They are wired in the factory, but every one I have seen has been loose, and the shims have fell out, which makes it all more loose (good Aussie english here), and knocking on take off, just as you describe.

These are a PAIN to check, and even worse to tighten, as to do it correctly, the shafts need to come out, and the brackets reshimmed.

If left loose, 2 things happen, 1) they sheer off, 2) the movement puts excessive strain on the 4 bolts on top of the cradle and cause the cradle itself to crack and split. Over the years I have replaced 4 cradles due to this top bolt area cracking due to the lower bolts being left loose.

 

yes i had a quik look at the exhaust its dificult to tell .one looks a bit close to the body .may be if i stik a rag inbetwen and se if that will identify the noise

 

ops forgot to put spell check on that .my secrets out .not very good at spelling. o well

 

this looks the most awkward solution. so being on a xjs probably the right one thanks for the help

 

as i drove back this morning i noticed a little squeak coming from the front RH wheel when i stopped to look if i move the car just a fraction with gentle rocking motion it squeaked any ideas [o their were no earrings present in the car]

 

Hahahaha, no ear rings, I saw that years ago, classic. If you get some ear rings then the Jag noises become secondary, no more problems, mmmmm.

Probably sway bar bushes, the links and or the "D" rubbers. Links are simple, grade 1 stuff, the "D" rubbers, HAVE FUN, your vocabulary will expand, very easy with the radiator out, REALLY.

Might be shocker bushes, top mainly let go on these.

Spray some "silicone lube" around in one spot at a time to try and identify the area before ripping all non-relevent stuff out of the car.

 

How about the U-joints?