Jag Front Springs

[ryan]

Whats the general consensus on removing the front jag springs from the donor running gear.

I've read the easiest way is to cut through them using oxy acetelene but I don't have access to such kit.

Will I be OK attacking them with a cutting disc on an angle grinder or should I try and source a spring compressor and do it properly.

Also, am I right in thnking I should be able to just unbolt the rears without any nasty surprises.

Cheers

Ryan

[nearly thers]

All I'll say is that if you are going to treat a coiled spring of 1/2" diameter with the attention of a cutting torch or a disc cutter then you should be prepared to call 999! That is if you have any fingers left!

Get or make a tool for the job! I used some 1/4 plate steel drilled for lengths of 1/2" studding. It was a long time ago but I remember that this is a process that needs care!

Good luck

Neil

[Dutch Paul]

Originally Posted by nearly thers

All I'll say is that if you are going to treat a coiled spring of 1/2" diameter with the attention of a cutting torch or a disc cutter then you should be prepared to call 999! That is if you have any fingers left!


Neil

A cutting torch IS the easiest method (done at arms length)
My oxy bottle was empty at the time so I did mine with the angle grinder without personal damage, although I strongly DON`T recommend this route as at minimum you WILL wreck the cutting disc, closely followed by fingers etc

The rears are no problem.

[kayjayd]

Mine had already been but through twice each spring with a gas axe and they still went off with a tremendous bang when I unloosened the spring pan. I think the general consensous is to gas axe them. I personally would avoid going anywhere near them with an angle grinder, you'll crap yourself when they let go. God know what could happen!!!

[cobrarick]

The Jag engineers have very thoughtfully placed holes for this exercise. One in the centre of the spring pan at the bottom, and one in the subframe member above the top of the spring. This is to accommodate a single threaded bar (I have just done mine. Use a 3/4" dia section - I had whitworth thread to hand, but any co**** thread otherwise you'll be there all week!).
This can be purchased at a builders merchant, or engineering store, and usually come in 1m lengths. You will need a minimum of 18" length! You will need min3 nuts and a couple of thick washers min1/8"-1/4"thick, and wide enough not to pull through. The top one is tricky, as it is at an angle you will need a bit of engineuity with additional metal clamped to get a level (or you may have an angled block) whichever - make sure there is still plenty of thread left.
By the way - this is the third set I've done now, the very first spring shot off an tore a hole through a fibreglass car body when I used an alternative method. I was lucky I was not in the way!!!! treat these springs with utmost respect!!!! I would certainly not use any other method than this one I'm describing. This is how they are put on in the first place.

Right. Cut the threaded rod to the suitable length and pass through the holes so it is inside the body of the spring. Still holding the rod, Place the angled block over the top so it sits on the subframe and then Place a thick washer on and a nut at the top to stop it falling through. This needs to be turned down the rod so there is just enough rod protruding below the bottom pan to take the thick washer/plate and two nuts. Turn one nut against the other to lock the bottom nuts together (this is so the bottom nuts remain where they are) Only the top nut turns, and not the rod.
Tighten the top nut down to take up the slack, and then tighten another couple of turns to slightly compress the spring.
start to undo the bottom pan bolts, just turning each a few turns at a time - they should be relatively easy to turn and the pan should stay where it is after a small gap appears - if not, turn the threaded rod top nut some more to tighten up. Eventually all the pan bolts can be removed, and then the top nut can then be slackened off. It takes some effort, so don't be surprised, there is a lot of power in these springs. As the rod is central to the spring, the pan does not go sideways - unlike those external spring compressors used in pairs!!!
Keep winding the nut round, whilst checking the bottom nuts to make sure they are not coming off (you could always weld these, but it makes it more difficult to fit and remove), you'll be amazed at how long these springs are when finally tamed.
Unlock the bottom nuts and remove.
Ditto for the other side.


The rear shock absorber/spring units can be unbolted without any compression required.

Have fun

Rick

----------------------------------------------------
GD427 mkIII stroked 351w TKO - pick up chassis in few weeks time.

[ryan]

Cheers Rick,

A very thorough and helpful explanation, many thanks :thumb:


Ryan

[TonyD]

Originally Posted by kayjayd

you'll crap yourself when they let go.

Indeed you do ( well I blamed the curry from the previous evening ) !!

Cheers,

Tony:thumb:

[richc]

I don't know if older XJ6 assemblies are the same as the my XJ40 but I copied the tool from the illustration in the Haynes manual.
This consisted of a length of 20mm threaded bar with a hole cross drilled through at one end, this takes a length of 8mm high tensile steel (cut a piece from the shaft from an 8.8 bolt) that protrudes 10mm or so each side to form a T bar. This end is pushed up the centre of the spring, twisted 90 degrees then locates where the jag tool is designed to sit.

At the business end I cut a section of steel tube at an angle to create the wedge and tack welded a 6mm thick plate washer to the square end. The bar passes through the washer and the spring can be compressed using a nut as per the Jag tool. You could get away without welding as the plate can't really go anywhere.

Unfortunately I don't have a pic handy but the Jag manual will give you the right idea.

good luck

Rich