My girls got a saggy back side

Got my RHD Mk IV out of storage since spring has arrived. I let a friend drive her back to my house with me following. It;s one of the first times I’ve been behind my car and I noticed the drivers side (in this case right) hand side of the car’s rear was a couple inches lower than the left side. When we arrived at my house I immediately went to the front to see if there was the same lean. There was not. On a side profile it also shows a downhill slant from front to rear.

So it appears I have spring issues. I put it on the rank and could find no broke leaves, missing bushing etc. so I guess its just the age of the springs.

How have others dealt with this? Rebuilds? If so does anyone have specs (eye to eye measurements, drop in center, etc.) I can give to a spring shop?

Any other thoughts would be appreciated.

Jim Bolinger (48 - 3.5 liter saloon)

There are free camber, laden camber with load, and tolerance specs in the Service Manual page 68.
I re-arched the springs in my 120 by taking them apart, setting each leaf across a pair of wood blocks, and jumping on them until the top leaf matched the spec and the others matched the curve of the top leaf.

Hello Jim, given the frequency of restored cars sitting at non-original heights your information gathering and cautious approach is warranted from an aesthetic viewpoint. Springs need a combination of rates (springiness) and shape to hold the weight at the designed static position and do the dynamic role. If you are going to jump on this project, Rob’s method has a repetitive feedback loop in the process which can succeed with the existing leaf materials (assuming the sagging spring leaves are original).

I think you will find the chassis has rotted through at the front of the rear wheel arch where it transitions from the main 5” deep frame down the about 2”. At least that’s where it is on my car.


Indeed, it’s not uncommon. A quick way to check is look at where the vertical face of the chassis is spot welded to the flange of the horizontal. If corroded the spot welds will pop as the rust swells the two surfaces.Another indicator is sever rusting of the large bolts through the chassis that hold the bumper mounts. The cause of this is the rubber bungs in the rear jacking points.They prevent dirty water from the road escaping and so filter out the actual water and leave a residue of mud which progressively builds up.
We had to have a rear chassis leg folded up [ not that complicated and welded in. But this was on a bare chassis.
Otherwise , the corrosion [ at least in Aust,] should be mainly on the bottom horizontal face and perhaps the lower part of the vertical. and it may be possible to cut and replace this from under neath. It would probably need the springs removed to take the tension off that area.
Commiseratons either way.

Well got under her today and luckily it appears to be just springs and not corrosion of the frame. As pointed out previously I looked at the specs in the service manual and they indicate roughly a level (straight) spring when ladened. Mine appear to have a reverse curve with the center higher than the ends.

So I guess it’s time to remove then and see if I can get reached.

Thanks everyone for the points!

You willl need to take the loadoff th e springs . It’s a bugger of a job. The front shackle bolts are extremely difficult to remove at the best oftimes.
I took the exsystem off the car. And got along length of square tubing 2" x 2" long enough to reach between the rail. The Made a yoke. U shaped and about 2" wide and a long piece of all thread , as biga dia s you can get] vertically through the bottom of the U and through the square tube
The with the U bolts undone i was able to take the spring load from the front shackle bolt.
Of course there’s still the certant y that it will be rusted in
Most people undo the nuts , cut the head off with an angle grinder and witha drift try and hit it towards the outside of th e car. { NO room to hit it inwards. .
Then when the end reaches the chassis, cut it off with the grinder and hit some more , repeat as necessary
The rear involve taking more bits off.
It’s worthwhile replacing the bolts with new and have them plated and coated with moly grease
And there’s the washers on each side of the rubber shackle bush.
You can buy new bushes. If the 1 1/2 are narrower, One can shorten XK120 ones in the lathe.
There are hours of creative pleasure ahead of you.

There is a picture in the manual of the tool they used at the factory to fit the spring shackle pins.
Here’s how I did mine.


Looks good , How did you get on wt the front shackle bolts?

Haven’t touched them yet. My purpose in fooling with the rears was to remove, repair and reweld the main rear chassis crossmember.
A propane torch helped to loosen the old pins in their steel sleeves, keeping the heat on the pin, then letting it cool off and soaking with penetrating oil.
I will undoubtedly require your hammer and cut method when I get to the fronts.

Thanks Ed. Like everything else in this world it’s just time, money or both!