100 Series Torsion Bar

G'day Gary,

I have not done this to a 100 Series Cruiser but the reason to upgrade the IFS torsion bars can be sound. The reasons being that ...

1. As accessories are added (bullbar,winch etc) the original torsion bars might have to be (wound up) to restore original vehicle height because of sag from the extra weight. This increases the tension on the bar so it loses some of its spring action.

A new torsion bar would have a higher spring tension and hold the extra weight in the normal spline position ..so it would hold the accessories and still have full spring action.

A standard torsion bar with added weight giving it a "spring action loss" would potentially be a bad handler on corrugations. It all depends on the amount of suspension travel loss from adding the weight and the amount you have to wind up the torsion bar to compensate. Obviously full spring action would be the best for corrugations.

2. Original bars can sag. Aftermarket heavy duty bars are usually made from better steel and dont sag anywhere near as much as the original steel. A rolled spline on the bar ends verses machined is the better bar "quality".

IMO the criteria for an upgrade would be ....

1.The front of the Cruiser is down significantly from standard ..either by addition of weight or torsion bar sag.

2. The torsion bar had to be wound up significantly to bring vehicle back to original height.

Easy to check ... measure the distance from bump stops to where they engage chassis or wishbone on a standard cruiser thats fairly new or equivalent model to yours with minimal k's. Take note of the spline setting in its housing on the end of the torsion bar.

Compare this to your vehicle measurements and spline setting .... if very different see a suspension specialist for advice on a possible upgrade.

If both spline settings are the same and the loss of height is over 20% I'd look at an upgrade .... check with people that much more torsion bar experience than me thats for sure ....

Regards
Anthony

I have a 2003 LC100 Sahara. After installing a bullbar and winch, the front dropped by 45mm so I cranked up the torsion bars which lifted the front by 500mm and resulted in the toe needing realignment. End result is that the front is tighter than before, corners flatter and feels great.
Also fitted poly air bags inside the rear coils, pump them up to 25 psi when the BT is in tow. The combination of the additional torque from the Dtronic, a stiffer front and rear end together with the WDH results in a good balance and good ride in luxurious comfort.