Suspension- New Coils necessary?, Half Shaft- why cant I disassemble?

[72_240Z]

hello everybody,

i am in the process of rebuilding my fathers 72 240z and have a couple questions. I want to replace the suspension and i am wondering if getting new spring coils are necessary. i have no idea when they have been replace but it looks like after market cartridges have been installed. For the springs I'm just going to assume they are 40 years old and was wondering if i could get some opinion on the subject.

for the haft shaft the rubber boot had some reasonably sized holes in it so i cut it off. i unclamped the snap ring and thought the shaft would just slide out of the sleeve but it does not. i have been staring at it for a while and don't know what to do.

also i cant seem to remove the rear axel shaft from the strut assembly. i removed one of them using a 2 arm gear puller, on the second one however it just keeps popping off as i tighten it. i have been hammering on it using a 4x4 as a buffer but all i seem to be doing is splitting wood. i even took a touch to it to see if i can get it to expand a little bit but im not getting any where. if you have had any success with this i would be very interested in hearing what you did.

any help would be greatly appreciated

thanks

[Carl Beck]

A couple years ago - I took an original set of springs to an automotive speciality shop - that had a spring rate measurement device. The set was off a 1970 240Z with about 80K original miles. All four springs checked out to be within the factory spec.

Age doesn't seem to be much of a factor - but I'm sure that wear/tear are. It is possible to have springs that are sagging due to fatigue.. I'd measure their Free Length and if within the Factory Spec. - they are most likely OK. While it is hard, you can measure their compressed lenght - while on the car. The results would also give you a clue. The measurements can be found in the Factory Service Manuals.

This is a good article on how to replace the stub axle bearings.

http://www.atlanticz.ca/zclub/techtips/rearwheelbearings/index.html

If you have strut off the car - I've had luck heating the strut - then using a large brass hammer and piece of heavy steel plate - to pound the stub axle out from the inside. Make sure you leave the stub axle nut in place at the to of the treads.

On one strut - I had to take it to friends 20 Top Press - and even then we had to heat the strut. Most of the time the above will work.

Using wood - isn't effective. The wood absorbs/dissipates too much of the energy from the hammer blows. A large heavy brass hammer is most effective.

FWIW,

Carl B.

Edited February 28, 2012 by Carl Beck

[Zed Head]

Don't know if this will help, but here's a picture of a disassembled half-shaft - http://purplesagetradingpost.com/sumner/bvillecar/construction%20page-23.html

There are drawings in the FSM also, Rear Axle chapter.

[Casey_z]

If the strut is still on the car this slide hammer worked for me.

Casey

[SeafireXV]

As a mechanical engineer freind of mine explained to me a few years ago, by their nature steel alloys have infinite fatigue lives as long as you do not exceed the elastic limit of the metal. If your springs saw normal use then they are probably fine. This is not the case with the family of light metals such as aluminum, magnesium, titanium and so on. They will perform a designed task for a specific number of cycles and will ultimately fail unless they are re-tempered. Any engineers out there please feel free to elaborate.

[jmortensen]

It will be easier to buy a good used halfshaft than to fix the one with the torn boot.