Thread: RRC coil spring sag

I weighed my RRC (with Isuzu diesel) almost 10 years back. The drivers side was 60kg heavier, but I put this down to the offset in the diff heads and prop-shafts. Which is primarily unsprung weight.

With equal springs and a front axle from a disco with straight radius arm brackets mine now sits level within 10mm or so. With the original front axle and misaligned radius arm brackets it took 1 inch of spring spacers to even it up. When you jack up the front, check how level the front axle hangs.

I don't subscribe to the "longer springs for the driver". I put longer springs in the left side to counter the camber on the road and make the vehicle sit level when driven. The nissan road cars I owned run the same way, unloaded they are approx 10mm lower on the drivers side.

Today I got under the car and cleaned the rear springs to find the paint codes .
They are painted red and white indicating they are for RR Classic however I notice in the page supplied by Philip A that there are different springs listed for the EFI model which my 89 model is .
I notice the spring lengths in the listing shows 2 different length rears for my model one for the left 17.13 inch and one for the right 16.47 inch. Spring length varies by over half an inch !
I think this is my problem ! Although Im a little confused with the lengths indicated having the larger one on the rear left (I assume this is the pass side in aus ) which is the side already higher with the springs currently fitted . Looks like it would be right to fit them in reverse and it would level up the car .
Anyone know whats the go with why different lengths used in EFI models ?

Just pull them out and sit them next to each other and put the longer one on the sagged side if you don't want to spend anything.
If you are a stickler like me, measure them vs spec and repalce them if they are short.
Regards Philip A

A bit late, but this may be able to help others.

To determine which spring has sagged, start at the rear, jack the low side of the body so that the rear sits exactly level. Measure from the bottom of the rim to the guard. With the rear level, measure the front. See if both sides are the same. If they are, then the rear has sagged. If they are different then the front has sagged.

Originally Posted by Not_An_Abba_Fan

A bit late, but this may be able to help others.

To determine which spring has sagged, start at the rear, jack the low side of the body so that the rear sits exactly level. Measure from the bottom of the rim to the guard. With the rear level, measure the front. See if both sides are the same. If they are, then the rear has sagged. If they are different then the front has sagged.

I can't see that method working. Forcing the body to one position and then measuring springs won't show much at all. If the fronts measure differently when the rear is level, then either one front tyre is flat or the chassis is twisted.

Taking springs out and checking the free length against what they used to be is the only accurate way. Unfortunately springs vary by a fair bit in length just due to the way they are made. You need to have measured the springs when they were new to get a comparison.

The only way springs lose ride height is:
1. If they have cracks growing through them (a concern if they do)
2. They yielded (shows as a reduction in free length) due to insufficient material strength or bad spring design.
3. The load has increased.

A vehicle listing to one side can be caused by any number of bent chassis or spring components.

What I ended up doing was swapping the rear springs side for side and presto she was as close to level again .
But guess what ?
A couple of months on shes slowly going back down on the drivers side . Not bad but has dropped about 10 mm

Originally Posted by Dougal

I can't see that method working. Forcing the body to one position and then measuring springs won't show much at all. If the fronts measure differently when the rear is level, then either one front tyre is flat or the chassis is twisted.

Taking springs out and checking the free length against what they used to be is the only accurate way. Unfortunately springs vary by a fair bit in length just due to the way they are made. You need to have measured the springs when they were new to get a comparison.

The only way springs lose ride height is:
1. If they have cracks growing through them (a concern if they do)
2. They yielded (shows as a reduction in free length) due to insufficient material strength or bad spring design.
3. The load has increased.

A vehicle listing to one side can be caused by any number of bent chassis or spring components.

Using this method assumes tyre pressures are equal left to right.

Forcing the body to a level position will take the load off the springs on that end so that the sag will be seen at the other end.

Have been using this method to test for sagged springs for years and it works every time.

Springs will sag, they lose their tension. Spring steel will not retain the same elasticity for ever.

I will agree that taking them out and comparing their free height to their original height is the best way, but the quickest way to determine which end has the issue is the method I have described.