How do I identify the torsion bar sizes?

[ZOA NOM]

I'm not sure what size the torsion bars are in my car. The PO made several upgrades and mods to the car, and I wouldn't be surprised if he put in larger bars. Is there a way to tell without removing them?

[ZOA NOM]

bump

[kstylianos]

Probably the easiest way (and most accurate) is to mark the spring plate angle in reference to the chassis, and pull the bars and check. When you replace, match the reference points back up.

Or you can use Thoms and Wils spring calculator and work backwards. Measure your ground to fender lip distance and calculate the static spring plate droop. Plug in your vehicles weight and measure the angle of the spring plate w/o any load (keep this for reference). Plug the numbers into the calculator, varying the t-bar size until the measured angle matches the calculator output. This may give you your correct t-bar size within a couple of mm's.......lots of variables, not too precise.

http://vintagebus.com/cgi-bin/spring.cgi

[Jack Olsen]

Easiest method: ask the previous owner.

[ZOA NOM]

Thanks, I guess I knew it wouldn't be stamped on the end or something. I appreciate the feedback.

[Spud]

I was curious about this too, and after pulling the dust cover off I was surprised to see 26mm stamped on the bar end. If you haven't already looked you might want to.

My guess is every bar maker does not do this, but you may get lucky

[Eric Coffey]

Before you go to the trouble of removing a rear spring plate (only to determine T-bar size), you might just take one of the adjuster caps off of a front T-bar. It is a much easier job, and since most people that upgrade T-bars will do all four, I would assume that if the fronts are stock 19's (18.8mm), then the rears are probably stock too (25mm).

[ZOA NOM]

No way, Spud!!! I was joking! The car is getting new rubber right now, but you can bet I'm pryin' on the T-bar caps when she gets home.

Awesome, I'll post when I find out.

[Spud]

Hope it works out... Unfortunately I still don't know the size of my front bars, although it sounds like this can be figured out almost as easily!

[marcesq]

If you have the torsion bars out, measure with an open end wrench by finding the right fit in the middle of the bar. If you don't have anything larger than a 21mm open end, use a cresent wrench and measure the distance between the jaws.

Sorry Charlie . . . I don't know how to use a protractor.