Can anyone that has a 120Y workshop manual pls tell me what the std spring rates are.
N/mm or lb/in.

Changing my suspension & want to do the maths up front to save time stuffing around to get the correct ride height / pre-load / sag etc. etc.

Thanks in advance.

Well I've had a look in mine and I don't think is exactly what you want but I think they just had no reason to put that info in since manufacturers just like to "replace" things. Taken off page FA-16 of FActory Service Manual, released 1976 (April I think)

Coil Springs

Wire Diameter - 10.5 mm (0.413 in)
Coil Diameter - 100 mm (3.94 in)
Coil Turns - 9.0
Coil effective Turns - 7.5
Free length - 357.5 mm LH (14.07 in), 346.5 mm RH (13.64 in)
Spring Constant - 1.62 KG/MM (90.7 lb/in)

Later ones with A/C had a rate around 95/lbs.

The spring rates seem to be very close even in different countries. Here's a list of various rates:

Quote:More specs: Front Suspension Specification

I forgot to look up the rear suspens specs, I'll do it later, have to paint up a filing cabinet right now

going up to 190 - 200lbs is still streetable. Maybe 225lbs but that would be stiff.

Presumably you still have an A series, or you'd want heaver ones.

I think the rears were in the 100 - 125 lbs range depending on if it was a sedan or wagon/liftback. Leaf springs? No idea.

I have a FSM for the 81 120y(b310 whatever) so I should have that info.

Is it just me or are the oem spring rates for the front roughly 1/2 the engine weight minus a bit...

Hey guys thanks for the info.....

Ended up being arbitrary though as I couldn't get spring rate info for the springs I was replacing the 120Y items with (Gemini variable rate coils) to allow doing the calc's up front... Was trying to save time.

Ended up pulling the struts out 3 times before I got the ride height right....
Worth it though.... With the new springs, KYB shocks & a 120Y swaybar the handling has been totally transformed.
Corners like it's on rails now .

Hmmm I wonder could I set the old 1200 swaybar up in the rear.......?

Able to post a pic up of said ride height? or just how many coils came off?

Umm, I'll try & get of my proverbial & take some recent photo's of the ute... Haven't taken any since before it was mod plated.
Here's the last one I have... Ride height is basically the same.




Have approx 45mm clearance between the tyre OD & the guard lip... Running 14's with 185 x 55's.

Took approx 3 & 3/4 coils off the Gemini springs.
Final gemini spring length was 250mm.

There was a bit of issue with the droop as the spring length was shorter than the shock travel.
It was alright once I got them in as the radius rods & swaybar held the springs in the right place, but I ended up drilling some small holes in the spring perches & the springs themselves & securing with tie-wire to make sure they were located correctly while I was re-assembling.

Lots of stuffing around, but the result has justified the means