Front Suspension Fixes

[TMKHUM]

I've fixed a couple problems with the front suspension on my H2, and wanted to pass it along:

Problem 1: Snap or popping noise heard from front left of vehicle apparent during braking or turning.

Solution: There is a TSB on this which recommemds elongating the driver's side cross member holes and retightening bolts to 89 ft-lb.s. The real problem is too low of tension in the bolted connection. With the loading on the cross-member and 'low' bolt tension, the cross member shifts relative to the frame and pops. I know one of the hummer tech.s on the board suggested turning the bolts an additional 3/4 turn. This is along the right path, but will most likely yield the bolts which will prevent you from building addtional tension. The suggested fix is to go to higher strength bolts and a higher torque. The stock bolts are 10.9 quality with a max torque of 90 ft-lb.s. I have replaced these bolts with 12.9 quality (about 20% stronger) socket head cap screws which are torqued to 110 ft-lb.s This has eliminated the popping noise. (I went this route after the TSB didn't work)

BOLTS : 12 mm X 165 mm M12 12.9 bolts SHCS
Loctite medium strength
Re-use factory flange nuts
Use flat washer and locknut at the bolt head
Make sure all the corrosion coating is cleaned from threads and contact areas.

Problem 2: Brake dive

Solution: Well quite a few of us have cranked our front torsion bars for a bit more lift. When we have done this, the lower bumps stop does not or barely touches the lower a-arm. If you look at a proper z height setup, the lower arm is touching the bump stop.

Well, I read an article last week on the GM front suspension. It said the bump stop is actually part of the total spring rate (combined with torsion bar rate). It went onto say the bump stop also helps to minimize torsion bar fatigue. I fabbed a pair of spacers that dropped the bump stop a 1/2". After doing this, brake dive has decreased considerably. I was actually surprised how effective this was. The proper way is to mold a longer a bump stop, but the spacer works.

Hope this helps. The usual: use at your own risk.