ejsmall

Re "Resetting"
This is probably a long-shot, other than that it could be scan-tool/Tech2 or 03/06 BCM compatibility issues, though one would think GM would have kept upgrading simple.

Re Wiring
I certainly up-date my drawings, it's all good information for anyone else wishing to update their Air Suspension.

Re Jounce Bump Stops
Well done on doing all the research and thanks for feeding back your findings, no doubt others will need theirs replacing in the future, so I'll keep looking too.

Your measurements are very close to mine, normally I'd measure and 3D model it, but mine are in poor condition so a bit too risky until there's a replacement.

Perished is the word

 

Just ordered a Transit van Bump Stop from Amazon, looks to be a similar size, will report back on Thurs.

 

Another possibility. There were also Hummer H2's built in Russia but I'm unsure if they had the exact same suspension options (I'd assume so but maybe the ones built there were only coil spring). I wonder if possibly the rear jounce bumpers for the air ride models (ZM6 RPO code) might be available somewhere overseas? Out of curiosity I did a quick search and did find this page https://avto.pro/part-15062871-GM-770/

That one appears to state that it is available in Kiev so I'd certainly want to contact to be sure if any place overseas truly has them and well, that particular one is in Ukraine so hard to say either way with the war and all over there.

 

This one if for a Transit Van is looks very close and very cheap, it's 0.5" longer BUT maybe not strong enough even though it's off a large truck

Not sure if the H2 ones are more solid or how they behave, but this one I can partially depress by standing on it.

Any thoughts?

 

It looks like the base isnt as deep to fasten properly in the mounting cup.

Im going to buy the Timbren SES bump stops. I like the idea that these are designed to support the truck for loads. But Im going to wait about a month before I order them as we're still in winter with salty mess on the roads. I wont be driving the truck until probably beginning of April and want the 100 day return policy to be still in force in case it causes any ride harshness.

Timbren asked me to try the version they make for the H2 coil suspension and if I dont like it they will modify it accordingly for our air ride suspension.

Stay tuned.

 

Thats definitely them. Of all places Ukraine... who knows if still actually in business or could ship to US. Would probably get delivered by a couple of Federal agents with questions. Probably be $170 for the parts, $400 for UR taxes, and $1000 shipping!

 

Hey all. Im finally close enough to getting my H2 back on the road that I went ahead and bought the Timbren SES (Suspension Enhancement System). These are a glorified bump stop which directly replaces the OEM rear bump stops. In concept I like these as they will hold the truck up in event of an air ride system failure. They are a ridiculously pricey at $285 delivered from Summit Racing, but they are pretty beefy and have lifetime guarantee.

Removal of the original bump stops was easy and theyre actually in pretty good condition. Issue for me is that my new frame was from a coil spring truck and mine is air ride, so the frame came with wrong bump stops.

Installing the Timbren stops was a bit of a challenge. What worked was raise to the ride height to max level. I sprayed Rust Check which is a good lubricant into the cups, then push the stops in just enough that they stay. I stacked a couple of 2x4 peices between the axle and Timbren stop, then lowered the ride height to normal level. This pushed the rubber base into the mounting cups.

I was worried that the larger Timbren bump stops would interfere with the air spring. But once fully seated they look safely spaced.

Next is to get the truck out onto the road. There is about 3/4 inch gap between the bump stop and the axle at normal ride height. Either it will ride smooth, or Im going to feel every bump which contacts the bump stop to the axle. We'll see.

Timbren said these were intended only for coil spring suspension, but they told me to go ahead and try them. They said they would customize the bump stop based on how it performs for me. So either these will work well, or Timbren will have an air ride specific model after Im done testing.

I'll give update soon.

 

ejsmall good job in in fitting the Timbren stops and thank you for sharing, no doubt there will be many other that will need to follow your work.

Indeed it will be interesting to see if the stops "bottom-out" let's hope they will be 100% OK 🤞

 

So I finally got the truck out for few miles of bumpy Maine roads yesterday. I felt no change in the ride quality as result of the Timbren rear SES. As mentioned previously, these are a direct replacement of the original rear bump stops. They are intended for coil spring trucks to assist with sagging under load. For an air ride truck, under normal operation, these would never come into play as the air ride will always maintain correct leveling. What these do offer on an air ride truck is redundancy. If the air ride system fails, the Timbren SES will keep the truck more level and more drivable than the OEM bump stops.

For me, what necessitated this was that I replaced my 2003 H2 frame with a 2007 donor frame. My original frame had air ride, but the 2007 donor frame was from a coil truck. My air ride was refitted to the donor frame, but the bump stops for an air ride suspension are no longer available anywhere. The Timbren SES product seems to be the only off-the-shelf option for missing or failed H2 bump stops.

So for me these are a success, albite a rather expensive success. Only caveat is that they might not be suitable for use on a truck which is used for more severe off-road conditions. The SES might limit rear axle articulation. My truck pulls a trailer and gets some use on loose surface logging trails and deep snow. The SES will be fine for those conditions, and peace of mind in event of air ride failure.

 

My 03 H2 is stuck in the max height on the rear. I've tried pushing the height button but nothing happens it only blinks but won't lower the Hummer back to regular ride height. Any idea what I can do or check to correct this issue? Thanks!!