The 'E' Type Forum

My series 3 OTS is unfortunately sitting a bit low on its rear end. So much so that on one side the wheel arch comes below the level with the upper part of the wheel hub. Whilst it looks ok it causes problems with raised areas of road and speed bumps with the exhaust scraping and getting damaged.

I am presuming that I will need a set of new shocks. But whilst I am about it what else would anyone recommend I should have replaced whilst its being done. New Springs? Wheel bearings? Bump stops? Other bushes ? Or other suggestions welcome.

Any idea how much we are talking here, as I will have to take it to a garage as I do not have the facilities or the mechanical expertise to do it myself.

Thanks.
Mike

SESH

Might I suggest that to do the irs rebuild all you need is time and a parking spot, preferably indoors.

I'm but a hobbyist and have the firm belief that if I'm going to pay someone to fix something...., why not give it a try first. I know I'm going to learn and heck might even fix it.

With all the information on the net and rebuild books the know-how is but a few clicks away.

Even Edd China did an Series 3 and is available on YouTube. Lots of good info and for the work you posted here to be done in the Dallas Texas area the shop bill would be most likely thousands.

Best of luck and post the results.

Mike, the bottom line for an IRS overhaul for a Jag is around ?3k. The logic is that if you don't know when it was last done, and a few components are obviously tired, then the whole lot needs at least looking at and attending to.

By the sounds of it, you will need springs and shocks, and these things on their own pretty well justify pulling the whole rear frame off the car. That's an easy job, but it is heavy and requires a couple of people and some jacks and a trolley.

Once the frame is off, it is prudent to change the rubber mountings, and at least inspect the drive shaft UJs, wheel bearings and diff oil seals. It's also a good time to check out the rear discs and callipers, and of course the pads, and refurbish / replace as required.

If the whole lot has to come apart anyway, then it's worth getting the frame blasted and painted.

It would be worth hunting out a one or two man Jag specialist near you, as I'm sure this won't be the last work you'll need.

Mike you have had some pretty good advice already. If you do decide to do it yourself, be prepared for a really filthy job in stripping it down. Years of accumulated grease and axle oil mixed up with road dirt makes for lots of scraping just to get down to the metal! Very satisfying though. It is an easy job to strip but you will need a big vice to press in the driveshaft UJs and maybe a press to split the hubs from the splines. I rebuilt mine using phosphor bronze bearings to replace the old roller and tapers used originally. (Not sure I'd bother again though!).

Finally, when you have it assembled, grease the bearings and UJs - you'll never get to them as easy again!

The JEC do an extermely good DVd on this subject, filmed during one of the Dave Marks seminars . It shows you almost everything you need to know about this subject

Last winters job was an overhaul of the suspension on my S3 OTS.
Total cost came in at a little under ?3k of which labour was a significant chunk, I would expect you could do it for around half if you have the facilities and do yourself, not hard by the looks of things..... I had all bushes, springs, shocks, wheel bearings and IRS cage mounts, bump stops and a few other odds and bobs replaced for both the front and back.

I remember driving it away and the grin on my face was huge afer the first corner! :D

The only other bit I would have considered was the rear brakes, I was thinking of upgrading to an RBR set up with their easy bleed but cost was a consideration, wish I had now though!

Andy

Dear Mike,
The shock absorbers don't have any impact on the ride height. They can more accurately be called "dampers", in that their function is to stop the springs from continuously doing an impression of Zebedee. They damp the oscillation of the springs which take some time to resettle at their given height, which is a constant dictated by the weight of the car.

If your ride height at the rear is out of spec, then the only things which can be done to change the ride height are the insertion of a spacer between the spring perches or by any knock on effect of adjusting the front ride height. Inserting a spacer, if large enough, may affect whether the dampers can damp effectively, as they be will overextended as a default and thus have less free movement. The only practical long term solution is the purchase of new rear springs, because the ones you have have now drifted from their elastic setting. Springs are about 20-25 pounds each.

Whether you need new dampers or not is a totally separate issue. I happen to have a spare set if you want to pm me.

kind regards
Marek

MarekH wrote:If your ride height at the rear is out of spec, then the only things which can be done to change the ride height are the insertion of a spacer between the spring perches or by any knock on effect of adjusting the front ride height. Inserting a spacer, if large enough, may affect whether the dampers can damp effectively, as they be will overextended as a default and thus have less free movement.

Yes and no Marek. Restoring the ride height by use of spacers will simply put the dampers back to mid-stroke at normal ride height and have no effect whatsoever on their functioning. What could affect it would be if the springs became coil bound at full bump, but this is impossible with normal open-wound springs which will accommodate more compression than the stroke of the damper.

I assume in Mike's original description he meant the wheel arch overlapping the upper edge of the rim, not the hub.

You can do the geometry Mike and work out how thick a spacer to use to get a required increase in ride height (it being less than 1:1). New springs are the best idea, on paper, but it's a bit of a lottery on spring rates from different sources and I've heard of people still not be happy.

The no-brainer for me would be to buy a set of threaded adjustable Spax or Gaz dampers and raise or lower the bottom spring mount at will, to fix a ride height issue. If the rest of the rear end is still working, just lube it and leave alone IMHO. Wheel, UJ and hub carrier bearings are all dead easy to check on the car, along with diff output bearings etc.

Yes, if the diff is leaking like a seive and the handbrake's dead or the calipers are weeping, then drop the IRS and have at it. But if it's all basically intact why bother? Just service the back end. Three grand seems astonishing, though I don't doubt some have paid that.

I assume in Mike's original description he meant the wheel arch overlapping the upper edge of the rim, not the hub.

Spot on Pete, sorry about my poor description!

I am not particularly mechanical minded, I normally know what is wrong with my cars but fixing them with my limited facilities, tooling and expertise is a recipe for disaster !!

I think I am going to have to take it to someone who knows what they are doing and get an experts opinion.

Thanks for all your comments they are most informative and helpful.

Happy New Year.
Mike

Dear Peter,
Two points:-
1/ The original poster has a ride height issue and wanted to replace the shock absorber as part of the fix:- I'm pointing out that the spring is what is needing attention, not the damper.

This wouldn't be so easily be confused at the front of the car, where the damper and spring are clearly distinct entities, the spring being the torsion bar. The equivalent to ride height/torsion bar adjustment in geometry at the rear is to make the damper body longer, either by using spacers or an adjustable perch, but the problem isn't a damper problem. The spring has aged and has now settled at the wrong length.

2/ My example was about putting in a spacer * in excess * of just restoring the ride height and the possible consequence.

kind regards
Marek

Sorry about the double (now triple) posting. When I hit 'send' the first time I got a message saying 'Failed. Debug PHP line 224' or some such, indicating the send had failed. Maybe it's the warning that needed debugging :-( Anyone else had the issue in case it helps our Admins?

Yes, I just got the same message, but avoided a double post by checking whether it had loaded which it had (mainly because I didn't fancy retyping the whole thing!).

Same here - I will check what is going on tomorrow. In the meantime ignore the message and your post should have been made. If you double post please click on the X button on the right which will delete one of them.

"I'm sceptical that anyone would knowingly drive a Series 3 down the road where the ride height was over-corrected by a 50+ mm from a 30-40mm custom spacer"

The previous owner of my car did exactly that - that's how I know! He did it because he was bottoming out on hump back bridges. I simply purchased new springs and restored the ground clearance that way.

kind regards
Marek

Heuer wrote:Same here - I will check what is going on tomorrow. In the meantime ignore the message and your post should have been made. If you double post please click on the X button on the right which will delete one of them.

Err, no can do - someone has deleted both already....

Marek, hang on to them. If our roads deteriorate further the megaspacers might come in handy :-)

Peter

That was me being helpful I am afraid - thought I would save you the trouble!