Ride height Mk2

[G4TRA]

After 35 years in my ownership my 1962 2.4 33,000 miler has developed a distinctive droop to one side. The driver side looks much lower than the passengers, so I guess its time to do some measurements. I intend to jack the rear wheels just off the ground to measure the front height and visa versa for the rear.

Firstly, I would like a guide based on body to wheel spinner centre as to what the correct ride height should be.

Should the rear springs be the culprits then I don't envisage any issues in changing them for a new set, however if the front need replacing I would like advise as to the removal of the road spring and its return, as I belive it is impossible to get a set of spring compressors into place. If this is right, what's the easiest way of dealing with the spring.

Also in a case like this for a 58 year old Jaguar, having sat on her arse for most of her life, do the rear or the front springs sag more? And also who is the best dealer to get good repro springs from nowadays?

I am just a gutter DIY mechanic and as such would greatly appreciate your assistance.

Thanks

Steve

[Ronniebiggs]

Hi,

Offhand I can't tell you front ride height, but on the subject of removal of springs you need a special compressor - you can hire one from Ken Jenkins. You need to remove the damper and the compressor goes up through the lower wishbone and is retained by a big nut etc at the top. When I rebuilt the front of my Mk2 with 420 Varamatic steering, I fabricated a compressor but the tension on these springs is high and if anything lets go it's a trip to casualty!

I think it unlikely a front spring will sag, but there's always a possibility of a coil breaking; I've known this on other cars. Worth a look.

Rear springs aren't too difficult to change, but...the bolt through the rear of the spring can seize solid and requires ingenious removal methods if so, generally involving hacksaws. The removal of the plates at the front can also be problematic as the small bolts rust.

Good luck!

Jay

[G4TRA]

Thanks for the info RB, I guess its a jack up front and back to see which is effecting the ride level.
I do need a set of shockers for the front, so a semi strip down and inspections is in order there as well as an accurate measurement of the rear ride height when the front wheels are off the ground too.
Steve

[G4TRA]

Well, I have done some accurate measurement/comparisons, measuring from the level concrete floor to the upper part of the wheel arches of the car. Based upon the front wheels just jacked off the ground the back sits at 57.5mm NS and 58.5mm OS, which would show that the rear springs are within a mm of each other. Jacking the rear wheels of the car just off the ground the front measures 63mm OS and 67mm NS indicating that the off side (drivers side) is 4mm lower than the nearside (passenger), due I guess to the front springs alone.

I have removed both shockers which, as I suspected are originals and somewhat tired, however I believe that shock absorbers have nothing to do with the ride height of the car and that the discrepancy is due to 60 year old tiredness within the coil springs alone.

I would appreciate any comments before I change the springs which looks fairly straight forward.
As yet I haven't made up my mind how to control the springs yet and there seems to be three choices.

1. Locate the proper tool and beg/steal/borrow or hire for a few days
2. Fabricate a compressor screw and plate arrangement.
3.Use the trolley jack method with a fat man sat in the car or on the wing for additional ballast.

Steve

[Ronniebiggs]

Hi,

Out of your spring control options, the proper tool is the preferred route.

However, if you wish to fabricate a compressor you'll need some large studding - I used M10. An issue is the angle at the bottom; this changes as the spring is compressed/lower wishbone raised so a flat plate won't do the job. I used an old ball joint, from memory a roll bar link, and welded that to the studding (you need to be a competent welder, see my earlier post). Then use one of the lower shock mounting brackets on the lower wishbone with that ball joint retained by a through bolt. A ratchet spanner at the top, with a big washer underneath, winds down a nut to shorten the studding length and so compress the spring. Plenty of lubricant on the threads etc. It worked for me, and I still have a full complement of limbs! I can't remember the required length of studding; too long and it fouls, too short and it won't reach.

Another issue is the springs may have packing plates to adjust ride height. Your old springs may already have differing thicknesses side to side, and you'll have to experiment a bit to establish what's wanted for new ones.

Hope all goes well.

Jay

[piman]

Hello G4TRA,

yes, the dampers have no bearing on ride height, unless properly seized which is rare.

I made my compressor out of 16 mm high tensile threaded bar, standard threaded bar is very low tensile and double length nuts (Normally used for connecting two lengths of threaded bar together). Probably over engineered but I thought the extra cost was not significant. It did the job anyway with no problems. Lubricating the nuts helps as well.

Alec

[G4TRA]

Thanks for the ideas guys.
What about 3/8 UNF 6" studding in place of the spring pan bolts? Take out one at a time and change over to studding plus nut, then lower evenly on studding? Would this work? If so what length of studding would be needed to fully extend the springs, ie would 6" be enough.
Anyone done this?

Steve

[piman]

Hello Steve,

i don't see any problem with that idea, it will just take a bit longer. I can't comment on the length but better too long than too short.

Alec

[G4TRA]

Thank you Alec.
I have reviewed a lot of stuff regarding this job and most (but not all) refer to using the Churchill Tool No.JD 6G to compress the spring before releasing the bottom spring plate, however due to costs I am going to try and do the job replacing the bottom spring plate bolts with 3/8 UNF threaded bar. Not sure how long they need to be, but I have six 18" lengths coming plus suitable nuts and washers.
Having found no one who has done this job in this manner, wish me luck............

[PPV]

This gent (http://valvechatter.us/?cat=533) on entry 37 has used the same method as you proose. He has lots of detail for anyone doing a refurb. It may help.
Best of luck and take care,

[G4TRA]

That's odd Paul, entry 37 shows the guy removing the road spring with a single central threaded bar arrangement. OK for removal but not too sure about re-installing the spring that way.
My idea is to guide the bottom spring plate off and back on the car using the threaded bar, that way the spring will be fully contained too and the load distributed between six points as well.

Here are a couple of solutions I found:

This guy here uses a combination of central spring compressor and threaded bar for guides: http://www.ottawajaguarclub.com/Members ... prings.pdf

This one here https://www.jaguarforums.com/forum/xjs- ... ngs-68414/ shows the problem (albeit on an XJ) of using just threaded bar on the lower spring pan and how the spring bends: "When you install the spring, when it is seated on the subframe at the top, with the spring pan in place but before compression, the spring and pan are at a considerable angle to the lower wishbone, as it is hinged about a point well above the extended spring's end. This angle gradually diminishes as the spring is compressed, but is never 90°

I guess this is true for the Mk2 as well?

[PPV]

You are correct. He used a different method for installing as per his info in that section (http://valvechatter.us/?p=2121). You will need to scroll down a bit to find it and the tool looks a bit like the Churchill one I think. Have you tried hiring off Ken Jenkins?
Regards,

[G4TRA]

Yes, works out at £70 including carriage.
A new one (repro) £150.
6 bits of 3/8 UNF x 18" bar £30.

Could make one, but the high tensile rod needed plus the tilt mechanism all contrive to beat me as a simple bodger

Steve

[G4TRA]

So here's the latest progress.

The 3/8 UNF threaded bar came today from GWR Fastners, well recommended, good price good delivery.

Looking at the new springs I reckoned that 14" would be sufficient to bring the old spring out, so cut the six 18" threaded rods into 14" lengths. This proved to be an over estimate and possibly 12" would have been sufficient. Threaded rod comes in 8", 12" and 18" lengths so there is a saving to be made by purchasing 12" in the first place.

Using two locked 3/8 UNF nuts the six bars were screwed in to take the place of each of the six lower wishbone bolts, and nuts locked into place to hold the spring pan to the lower wishbone, one by one. The anti-roll bar was released from the spring pan.

Using a fairly thin walled 3/8 UNF ring spanner the six holding nuts were realeased in a clockwise manner, leaving about a mm clearance each time. You will not get a ratchet spanner in there so it does take some time to bring the pan and spring down the threaded rods, but it is very controlled and releases the spring in a safe manner. Putting spacers between the nuts and the spring pan would allow you to use a ratchet spanner, also bringing the spring down on just four threaded rods (using the other two as guides) is possible and hence quicker. In this case for safety having a nut on the two guide rods is a good idea. Finally watch that the bar does not turn, so unscrewing from the lower wishbone.

So the off-side spring is out. It is 2mm shorter that the new one which is encouraging. Now to give a good clean up and put the new one back in.

[G4TRA]

Right, now having completed the replacement of the front springs and shockers I have a Mk2 that looks like its an off roader the front is so high and it still looks like it is lower on the drivers side as well, so that was a bit of a waste of time.