Fitting Rear Springs

Hi All…XK150 fhc…Currently re refubing the rear end so everything is removed…a broken spring one side so fitting a new pair…thought this was going to be simple…bolted rear shackle in place…then attached rear of spring to shackle…but when i lifted the front it was about an inch too short for the bolt to slide in place…measured up the new spring to the old and bush eye/eye was about an inch shorter but then it is old and probably sagged so longer…searched forum for fitting springs but didnt find anything…so had to resort to a jack and ratchet strap…fortunatly car is up on a ramp so could strap the end down and jack up in the center effectively lengthening the spring…finally got the bolts and spacers in place…so question…should they have just fitted straight in place or is it normal to have to “jack” them in…photo is a bit “busy” but you can see what iv done…Steve

Hi Steve –

I’ve replaced these on both of my '120s and you’re not doing anything differently than what I had to do. Yes, new spring pairs have a greater curve to them, so will appear as being shorter than the old ones. Also, replacing the pair when only one leaf of one side was broken is considered best practice so give yourself a pat on the back there. If you really want to go the extra mile, next time consider disassembling the leaves of each, polishing the leaf faces with a fine grit sanding wheel on an angle grinder, then slather them with anti-seize or heavy grease and finish by reassembly and a good wipe down. It does make a difference. Don’t tighten the front and rear bolts until after the car’s wheels are mounted, back on the ground and bounced up and down a few times. Tightening the bolts before this can stress the new rubber bushings. Shim the front eyes as appropriate paying attention to the forward spring rebond clips: sometimes the bolts securing these will wear a groove into the side of the chassis member if there isn’t enough clearance.

Hi Christopher…thanks for the reasurance…i had visions of haveing to remove them…yes spacers fitted inboard so plenty of clearance between chassis and springs…wasnt going to tighten bolts till weight back on the ground…point taken re polishing the leaves. …maybee for another day…will possibly spray some silicone lube in there…all the best…Steve

I had to go through a similar exercise to fit new leaf springs on my 140. I would like to say all is good, but the jury is still out. I built up a rolling chassis and then put the body back on. With the body in place, along with the engine, transmission and all the running gear, the rear end sits about four inches too high. I have my doubts that it will come down that far when the car is complete and running. I complained to the vendor about the fit and general quality (or lack thereof) before I knew just how high they would jack the car. The response? “What did you expect? They are only leaf springs.”

About 25 years ago I removed the C3661 rear springs from my early 120 FHC, supporting the car and the axle on jack stands, and re-arched them according to the specs in the Service Manual pg K5. When I put them back on I put the front bolts in first, then the rear shackles. Then let the axle down onto the springs. I don’t recall any fitting problems, and the ride height turned out as near to perfect as I could ask for.

I wonder, are there published arch specs for the later C5721 springs? Or would they be the same if the weight of the car is approximately the same?
It might be well to compare them to new repro springs.

Thanks for the replies guys…yes the service manual dosnt say anything about fitting the springs apart from “replace springs…once springs have been replaced on rear shackle and front anchor bolt…its then necessary to jack up spring to engage with axel”…will be doing this today…not yet sure why the axel cant just be sat onto the springs…re spring spec dont think this will tell me anything even if the vendor could supply the info…i will soon find out what the ride height is then have to deal with it with spacers…but 4in would be far to much…will keep you posted…just for info it would have been far more difficult if i had fitted the front bolt first then tried to fit the shackle end…Steve

Possible if you attach the axle with the spring in its lowest position it will affect the position the prop shaft runs once the weight of the vehicle is back on the wheels?

Hi Robin…yes…was thinking sit tbe axel on to tne fully lowered springs and fit shackles etc…jack up the axel and fit new shocks/dampers. …lower jack and the axel should sit o its lowest position held by dampers. …prop should then be in correct position to connect. …Steve…uh just a rethink…the service manual instuctions are for just removing springs leaving existing axel in position so yes you would have to jack the springs up to fit

Axel fitted no problems as detailed above…Steve

by the way…consider saving your old, if original, springs…as originals have some characteristics in shape of the ends etc that are different from current manufactured. There may be some who want the original separate leaves or original end shape to rebuild, re-arch, reassemble. Put em in classifieds or ebay. Nick

Hi Nick…are these original?..1960 XK150 fhc…each leaf has a square end…my replacements have the dimple and insert buttons but not square ends…the corners are cut off…Steve

I will have to let others answer about xk150 original springs details. I know only about the 120…Nick

Hi Steve, the springs are identical to my early 70’s replacement springs.
Original later model springs had a plastic strip placed between the main springs, the ends of the springs had a Denso like bandaqe wrapped around them to prevent the plastic strip poking out, done to help deal with squeaky springs, all detailed in manual.My car is the 1st FHC manufactured in 1960

Hi John thanks for the reply…what manual are you refering to…i have the Jaguar service manual but it dosnt give detail on 150 springs that i can find…the parts catalogue mentions on later 150,s a nylon interleaf between main and second spring…but no detail on shape etc…thanks…Steve

Steve, sorry I was referring to the note regarding the nylon interleaf in the manual. As I said my springs are identical to yours and they had the nylon insert and I purchased these springs from Jaguar spares in the 70’s. …

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