2 Inch Lift on H2.

[OrangeCrush]

Originally Posted by tomp

Mark, I dont think they will vibrate with front height that low. Something is not right. You can count number of "flats" while turning down TBS and see if it goes away - and if that was not it turn the TBs back up exact same number of flats. Make sure to have load off of front end when cranking them up or down. Also, jack each front wheel off ground and grab tire/wheel and try to lift and ot shake the wheel to check for bad hub bearings.. You could also check air pressure and balancing and did you get an alignment after cranking TBs?

Tomp,

Thanks man, I'll double check the air pressure. Tire balancing and pressure should be right since they were brand new when I did the lift. (like I said, I'll double check) The steering wheel doesn't vibrate at all at any speed so I'm assuming the balance of the tires is fine.

As far as alignment, I immediately had an alignment done. I even had them use the specs the manufacturer suggested.

I took a look at the front halfshafts and they shouldn't be in a bind. Like I said, the vibration is VERY minor.

I'll check pressure next.

Mark

[tomp]

Mark...do you have mud tires with large lugs on them? This will cause it

Edit: just went back to see your pics and "yes" that is caused by those tires. It's the lugs you are feeling so no worries there. I bet if you put your stock tires back on for testing, the issue would not occur. I had Mickey Thompson Baja Claw Radials which are close to the same pattern as those tires you have and they did the same thing. It shouldn't be that bad though. I would have them re-check balancing to make sure it's right. Tell them is vibrating really bad.

[OrangeCrush]

Thanks, I've got a set of stock tires I can try. Like I said, the vibration is MINOR but I tend to be anal.

I ordered a set of cognito UCA last night but thinking I should cancel the order.

However, it should make the truck ride better. (it's not bad now, I can hardly tell any difference) but I'm more interested in ride quality as far as when the suspension loads and unloads as you go over wavy roads.

Mark

[tomp]

Mark, longer shocks are more of a priority than the UCAs. The shocks are the first limiting factor and then second are the control arms.

[OrangeCrush]

Originally Posted by tomp

Mark, longer shocks are more of a priority than the UCAs. The shocks are the first limiting factor and then second are the control arms.

I didn't replace shocks but did use the extended shock bracket.

Mark

[Bimmer9938]

Its common with the Truxxx 2.5-3F/ 1.5 R lift at 70-71mph. I have the same lift, and its hardly noticeable and its a good reminder to slow down.

[tomp]

Originally Posted by OrangeCrush

I didn't replace shocks but did use the extended shock bracket.

Mark

Warning: the shock extensions I have seen are too tall for OEM length H2 shocks. To test this, ensure vehicle is on level ground at stock ehight in the front and resting on the bump stops, disconnect the bottom of the shock and see if you can push it up higher then where it would mount to the shock extension bracket. If you can't push it up where the shock's bolt hole goes up higher than the hole in the shock extension, you are either riding on a bottomed out shock if or slamming down on a bottomed out shock when the front end comes down on the bump stops. The latter is the case if you have cranked the TBs. This is true with all H2 shock extensions that I have seen to date. Yes, this is another mark against Truxx.

The reason this is a problem is because these companies assume the H2's shocks are the same as the 2500HD pickup trucks. The shocks are not the same and only have half of the travel that the 2500HDs have.

To correct this problem you must determine the proper amount to shorten the shock extension (to get your shocks into the right range of travel) or use the 2500HD shocks.

The reason the H2's have less travel is because they have extension and compression bump stops in them where the 2500HD shocks only have extension stops. This takes some of the travel away.

Here is the way you need to think about it: Consider the fact that you are pushing up the bottom of the shock much higher than you would be when at factory height and resting on the frame mounted stops.

If anyone doubts what I am saying here, call Rancho and ask them why their online Shock Specifications show H2's shocks with 2.5" of travel and the 2500HD has 4.6". You can also see in this same manual there is a symbol next to the H2's shocks in two places. This "cross" symbol is shown for both compressed length and extended length. This shock symbol is there to inform you of the included bump stops. Notice the 2500HD shocks only show the symbol once?

Also, for those of you thinking it is okay to rest on the stops - think again. Your shocks will start degrading very quicky as you are beating the heck out of them. I went through several sets of shocks and my ride quality went horrible fast - compared to a new vehicle. This was the cause of it!

BTW, my ride quality with torsion bars cranked is much better than stock now

[DuckTruck]

Here are the communications I had with Rick via email:

"give me a shout when you have some free time...I will always make time to talk HUMMERS...now more of a sickness than a hobby, I'm a HUMMER owner for life!!!

Rick

rick,

what size tires are you running...especially in width?

the iroks i am looking at are 13.50 wide.....do you think i will have
any problems with that width on my stock wheels with rubbing?

thanks again,

jdj

Jonathan,

I'm running 39.5 x 13.5 Iroks on stock wheels...as I mentioned, in the front, they rub on the swaybar at full turn...

The rear lower control arm pocket at the frame has about a 1/2" to 3/4" stiffening flange below & in front of the bolt hole...I've ground away the extra material to extend only 1/8" to 1/4" out from the face of the control arm pocket...The extra clearance made me feel more comfortable that I would not rip out the sidewall at low pressure...You don't want to grind it flush, because that may weaken the pocket itself.

The other option that I am toying with is to add 1/4" to 1/2" wheel spacers, giving you a little more room...problem with that, is any more than 1/4" spacers & you'll need longer wheel studs...

One other thing that I failed to mention during our phone conversation...I'm using Fab-Tech tie rods because stock ones are so weak...and x-tra suppout brackets on the Idler & Pitman arms to give them a little more life...

I'll see if I can send you a bunch of pictures in a couple of days or so...

Talk to you soon...I hope that info helps!

Rick
Thanks man.....great info.

JDJ

Rick,

Wanted to follow up and ask you another question......

I am almost 100% confident that I will be installing Cognito Motorsports leveling kit (2 - 3") when purchasing new tires. I also 100% certain that I will be running 39.5 x 13.50 x 17 IROKs on my stock wheels.

The question comes when trying to decide between radial and bias-ply. I do a great bit of highway driving, but have run bias-ply tires before (the 37" boggers I told you about).......it would normally be a hands-down decision, go radial. But I am worried about killing my (already lack of) power. Thus, the weight difference between the bias (84 lbs.) vs. the radial (99lbs.) really concerns me.

What do you think about this? Also, how do your bias-ply 40's do at highway speeds, etc.?

Thanks again buddy,

JDJ

Thank you.

I'm just concerned that when stepping up to 39.5's that my highway cruising will suffer even more than when stepping up to 37"s (ie the constant "transmission kick down" that we all so dread!).

Any input on this issue? How does your truck respond?

JDJ

Jonathan,

I had 37's on the truck from the time it was 2 months old...I didn't notice much difference in vehicle performance from stock, as far as mileage/transmission shift points/power. When I added the 39.5's the road noise increased substantially & the trans stayed in low for slightly longer (slightly slower acceleration)...as far as steep hill climbs, I manually shift the transmission, especially when towing up steep grades, so I wouldn't know about the kick-down pro's & cons...There is a way to re-program your shift points if you need to...

I'm in the process of modifying my 2007 to be just like the 2005...including the 39.5 Iroks!!!

I love the bigger tires...with the snow here in Michigan, the 2" body lift & the bigger tires make for a better drive in the country for me.

I got my 07 buried in a snow drift about two weeks ago...The 05 with the lift & tires had no problem with being stuc...I mean "Temporarily detained".

Best of luck with your modifications...Happy new year, hope to see your rig completed some day!

Rick"

There ya go,

DUCK

[OrangeCrush]

Tomp,

Thanks, I just happened to read your response.

Tomorrow I will unbolt the bottom of the shock. Just to make sure I understand, you want me to compress the shock so the bottom bolt hole in the shock goes higher than the bolt hole in the extension, correct?

I will do that tomorrow but I did notice that the spacing between the bump stop and control arm is about 1/4". Is that correct or no?

If I can not raise it higher than the shock extension bolt hole, can I buy longer H2 shocks?

Thanks for your help,

Mark

Originally Posted by tomp

Warning: the shock extensions I have seen are too tall for OEM length H2 shocks. To test this, ensure vehicle is on level ground at stock ehight in the front and resting on the bump stops, disconnect the bottom of the shock and see if you can push it up higher then where it would mount to the shock extension bracket. If you can't push it up where the shock's bolt hole goes up higher than the hole in the shock extension, you are either riding on a bottomed out shock if or slamming down on a bottomed out shock when the front end comes down on the bump stops. The latter is the case if you have cranked the TBs. This is true with all H2 shock extensions that I have seen to date. Yes, this is another mark against Truxx.

The reason this is a problem is because these companies assume the H2's shocks are the same as the 2500HD pickup trucks. The shocks are not the same and only have half of the travel that the 2500HDs have.

To correct this problem you must determine the proper amount to shorten the shock extension (to get your shocks into the right range of travel) or use the 2500HD shocks.

The reason the H2's have less travel is because they have extension and compression bump stops in them where the 2500HD shocks only have extension stops. This takes some of the travel away.

Here is the way you need to think about it: Consider the fact that you are pushing up the bottom of the shock much higher than you would be when at factory height and resting on the frame mounted stops.

If anyone doubts what I am saying here, call Rancho and ask them why their online Shock Specifications show H2's shocks with 2.5" of travel and the 2500HD has 4.6". You can also see in this same manual there is a symbol next to the H2's shocks in two places. This "cross" symbol is shown for both compressed length and extended length. This shock symbol is there to inform you of the included bump stops. Notice the 2500HD shocks only show the symbol once?

Also, for those of you thinking it is okay to rest on the stops - think again. Your shocks will start degrading very quicky as you are beating the heck out of them. I went through several sets of shocks and my ride quality went horrible fast - compared to a new vehicle. This was the cause of it!

BTW, my ride quality with torsion bars cranked is much better than stock now

[Egan]

Originally Posted by tomp

Warning: the shock extensions I have seen are too tall for OEM length H2 shocks. To test this, ensure vehicle is on level ground at stock ehight in the front and resting on the bump stops, disconnect the bottom of the shock and see if you can push it up higher then where it would mount to the shock extension bracket. If you can't push it up where the shock's bolt hole goes up higher than the hole in the shock extension, you are either riding on a bottomed out shock if or slamming down on a bottomed out shock when the front end comes down on the bump stops. The latter is the case if you have cranked the TBs. This is true with all H2 shock extensions that I have seen to date. Yes, this is another mark against Truxx.

The reason this is a problem is because these companies assume the H2's shocks are the same as the 2500HD pickup trucks. The shocks are not the same and only have half of the travel that the 2500HDs have.

To correct this problem you must determine the proper amount to shorten the shock extension (to get your shocks into the right range of travel) or use the 2500HD shocks.

The reason the H2's have less travel is because they have extension and compression bump stops in them where the 2500HD shocks only have extension stops. This takes some of the travel away.

Here is the way you need to think about it: Consider the fact that you are pushing up the bottom of the shock much higher than you would be when at factory height and resting on the frame mounted stops.

If anyone doubts what I am saying here, call Rancho and ask them why their online Shock Specifications show H2's shocks with 2.5" of travel and the 2500HD has 4.6". You can also see in this same manual there is a symbol next to the H2's shocks in two places. This "cross" symbol is shown for both compressed length and extended length. This shock symbol is there to inform you of the included bump stops. Notice the 2500HD shocks only show the symbol once?

Also, for those of you thinking it is okay to rest on the stops - think again. Your shocks will start degrading very quicky as you are beating the heck out of them. I went through several sets of shocks and my ride quality went horrible fast - compared to a new vehicle. This was the cause of it!

BTW, my ride quality with torsion bars cranked is much better than stock now

Sorry to bump and old thread, but I found this during an image search on Google and it turns out to be good timing because I am putting together my front suspension right now.

I have Cognito UCA's, Truxx shock extenders and keys, and plan to crank the torsion keys up 2" or so. I bought Bilstein 5100's from http://www.dmaxstore.com and after reading the above bold section I probably ended up with the 2500HD shocks (part# F4-BE5-D146-H1). I have the driver's side done and I had to compress the snot out of the shock to get it to line up with the bracket holes (I haven't cranked the keys yet).

If I ended up with the longer travel shocks from the 2500HD, do I need to go back to the stock lower shock mount or am I okay with the extended ones?