Torsion Bar Adjustment Experience

[TahoeRestore]

After doing a complete suspension and steering renewal 6 months ago, I suspected excessive rake (nose down). The Torsion Bars had never been adjusted and both Lower Control Arms were on the Jounce Stops (driver's side more).

I'm posting this to help others who may be doing the same job. Everything is stock including tires and wheels. 2003 LS 5.3L Flex, 4WD, ZW7 Premium Smooth Ride

I searched this forum quite a bit and found various guidance on the proper adjustment setting. I settled on adjusting for a small gap between the LCA's and Jounce Stops. Included below are before and after readings plus some additional info that may be useful to someone doing the same job.

I adjusted the torsion bolts in smaller increments at first till I had a good feel for the effected lift. I took the truck for a ride after every adjustment. This is critical and even more so with Nivomat (self adjusting rear shocks).

I had an alignment done afterwards and was surprised with the results. The prior alignment was six months ago. I was expecting a camber adjustment, but it was in spec (attached).

I hope someone finds this useful. Questions are welcome.

----- Data -----

Total turns on Torsion Bar bolts - Left 4.5, Right 3
Averaging lift per full turn - 1/3" (measured at the wheel well).

Jounce Stop to LCA pad:
Before - Left ******* pad, Right touching firmly
After - Both about 1/16" from pads (measured by slipping folded card stock in gap)

Wheel well to floor (all tires set to 35psi):
Before - L 33 7/8", R 33 7/8"
Final - L 35 1/16", R 35 3/16"

Wheel well to hub center:
Before - L 19 7/8", R 19 13/16"
Final- L 21 3/16", R 21"

Front Ground Clearance - Spec 9.8", As left 10"
Approach Angle - Spec 19.8 degrees, As left 24 degrees

 

[Marky Dissod]

Here, may be found, the last words of Joseph of Arimathea.
He who is valiant, and pure of spirit, may find the Holy Grail in the Castle of

He must've died while posting it ...

 

[Fless]

Your front jounce stops SHOULD contact the LCAs at ride height. Technically they're not "bump" stops.

 

[TahoeRestore]

Here, may be found, the last words of Joseph of Arimathea.
He who is valiant, and pure of spirit, may find the Holy Grail in the Castle of

He must've died while posting it ...

Nope, still kicking here. I was hoping others would find it useful when doing the same job. It ends with the data and alignment results as a reference. Is there something I missed?

 

[TahoeRestore]

Your front jounce stops SHOULD contact the LCAs at ride height. Technically they're not "bump" stops.

Your front jounce stops SHOULD contact the LCAs at ride height. Technically they're not "bump" stops.

Thanks. I found some who say they should contact and others who say it should be slightly clear of the jounce stops. My front was low (raked) and the driver's side was compressing the stop. I chose to adjust both to slightly clear the stops. All looks good now and the ride is fine. However, I was surprised that there was no camber adjustment needed afterwards.