H3 Long Travel Build

[Keith]

Wow, that is some pretty cool tuning software.

But, what happens when a sensor is out of range and the pressures are not what they should be. Also, the Isolator Converter valve bore is a sore spot in these transmissions. Using the new valve works good in worn bore. Torn up converter clutches that plug coolers is a bummer.
I also see quite a few broken accumulator springs, this will help.
The mods to the servo keep the unit from shuttle shifting 1-2 1-2 1-2 and takes the flare out of the 2-3 and 3-2 shifts. I can give it a quicker release from reverse. Even though it will have a 13 vane pump, it will help to reduce the pressure spikes in the main line.

You can still tune the shifts. Most peeps think a shift kit is something that makes a trans bang gears. That is not what this kit is intended to be. It is more of preventative / correction package. They don't shift hard at all, just clean, no overlap, and no flare.

I don't know squat about tuning the trans shifts via the computer program. I can understand though how you can tune the shift points via VSS and TPS, as well as TCC apply.

Do you change the EPC pressures for each shift to shorten them up and create the feel? That seems like a shot in the dark on the first tune. This is not a stock rig that you are familiar with. Vehicle weight, tire size, engine torque, gearing, high/low range, etc will all have a large effect on the shift itself. I can't see how you could get it perfect on a basically mail order tune. You might need to sit in the rig and drive/tune, even if I did not mod the trans. Remember, these trannies have a vane style pump. The rings don't like high line pressures, especially with spikes, and it also wears the slide pins.

Forgot to mention, I'm sure it will have at least a plastic forward and 1-2 accumulator pistons. Those will be changed to aluminum.

EDIT.. The 3-4 clutch pack going in will also shorten the 2-3. The clearance will be cut in half in that pack.

[waynehartwig]

See, that's the kind of answer I haven't been getting - makes tons of sense now! I'm in no way a tranny guy. You've probably forgotten more in the last 15 minutes than I know

In the one picture you can see the max pressure of 92.8, that is a global. So no matter what other adjustments you make, it will never see over 92.8 psi. Pressure is calculated based on the current on the force motor, which also has it's own table to dial in - ie at this current and this trans oil pressure, it's this psi.

From there I can change the amount of pressure at any shift point, based on the calculated engine ftlb output. Essentially increasing/decreasing firmness of the shift. There is also a brake and coast table, which will go negative on the calculated ftlbs. Which is great for trucks that tow heavy loads in the mountains; I can increase the shift pressure during decel and essentially give the rig a trans brake, much like if it had a stick. There is also another table in the fueling section where I can shut of fuel to the engine during a heavier decel, which also acts like an exhaust brake (kind of).

As for rig differences, that's kind of already in there based on the amount of power required to move the rig at the velocity the driver wants.

I really love these newer GM vehicles. Literally, if you don't like the way it drives, it can be changed by a quick hookup with a laptop.


So I think for now, I'll leave the shift firmness alone and just set up her up/down shifts, to keep it from hunting on hills.

[Keith]

Dang, I need to learn what you are doing. I can see that being a huge help for particular vehicles after a build. Sweet.

[waynehartwig]

Originally Posted by Keith

Dang, I need to learn what you are doing. I can see that being a huge help for particular vehicles after a build. Sweet.

Now you can understand my scepticism for the shift kits Seems we both learned something, and that's a good thing. I'll no longer be critical over the shift kits. Heck, I may just have to put one in mine now!

[66CJdean]

All I have learned is Wayne and Kieth love Tranny's

[waynehartwig]

Originally Posted by 66CJdean

All I have learned is Wayne and Kieth love Tranny's

lol
Tranny's? Naw.... 98+ up GM's, yes. The amount of tuning power (configuration) GM gives in tuning these are incredible! Take that and the fact that it's pretty much the same clear across the board. Not much changes between an I5, like in the H3 to a blown LSA in a 2010 Cadi. What is there, like 8 PCM's in the entire GM fuel (gas, not diesel) class? Vortec, P01, P12, P59, E38, E40, E67, E69 - then there are two Tranny modules; T42 and T43. I think that's really it? That stems from 98-2010 haven't seen any 2011 stuff yet, but I'm sure the E67 is still king.

[Keith]

Originally Posted by 66CJdean

All I have learned is Wayne and Kieth love Tranny's

Well, we have always known that Dean likes shafts

[Bebe]

Jeff has been biiiizzzee!!!!!

Drop Cradle and mounts done



Skid Plate/Steering Rack Supports





Upper Bracing



Center Section back from being Blasted (thanks WeBilt Dave :-)





The most exciting part for me....the Lower A-Arms are on the table

[waynehartwig]

You gonna powder the center? Or splash some paint on it? Pink?

[Bebe]

Originally Posted by waynehartwig

You gonna powder the center? Or splash some paint on it? Pink?

It will be Painted, satin black....I asked Jeff, he said there will be some pink on it - but again, he won't tell me where

I think we might also be coming up with a design contest for my skid plate...we'll see.

[Bebe]

A fellow Hummer owner (CHOmie) sent me this lovely gift for my H3 build:



Get it on that

[NorCalPR]

Looks great Bebe!

[atvobsession]

Originally Posted by Bebe

A fellow Hummer owner (CHOmie) sent me this lovely gift for my H3 build:
Get it on that

[77blazerdriver]

So what are the plans for coilovers and locker?

[Bebe]

It just came in today

35 spline ARB



As far as shocks, I'll be getting some Fox 2.5" coilovers for the front and some Fox 2.5" piggybacks for the rear. Both will be 10" travel.

[DarkCharisma]

I read all 8 pages, sorry if I missed it, but are you going to be using the stock hubs, or using 2500HD hubs?

[Bebe]

Originally Posted by DarkCharisma

I read all 8 pages, sorry if I missed it, but are you going to be using the stock hubs, or using 2500HD hubs?

Stock knuckles and hubs.

[DarkCharisma]

Originally Posted by Bebe

Stock knuckles and hubs.

The stock hubs in the 2500HD's and 1500's (In my experience with both) are generally pretty weak with even 35" tires and stock amounts of travel; Are the H3 hubs going to be any stronger, and will you need to run any adaptation to the CV axle to get the CV spline to fit into the hub?

If you covered all this already I apologize, I'll go back and read it again, just skimming between projects here at work.

[Bebe]

I guess that first we should make sure that we are talking about the same part and that we are using the term 'hub' to mean 'unit bearing'?

I have heard this before, in this thread and others, but am always curious under what conditions they are weak. Not trying to disagree, but people often time say parts are weak yet offer no examples or experiences/solutions as well.

I have never had a problem with mine. I have been on the same hubs/knuckles for 116k miles in 5 years. About 90K has been with 35" tires, wheeling, Moab, Rubicon and Fordyce, along with many other Sierra Trails. They sound great when you give them a spin, don't leak, but at this point I do carry a spare JIC.

I understand that 38's are bigger, but I have seen H2's run 37's and have over 100K miles and have never replaced a hub (and they wheel them).

Maybe the H3/H2 hubs are different than the GM 1500/2500/3500? I know we had to modify a GM 1/2 ton chevy hub to work on the H3 we repaired in Moab (we had to change the wheel studs because the shoulders were hitting the brake rotor).

I also know I drove home to NorCal from Ely Nv (400 mile) with no front axles. We had no issues with the bearings. A couple of folks we talked to after told us NEVER to do that again

I don't know why they would be different, or why the GM version of the part would fail more frequently before the Hummer parts.

I know the H3 UB is about $200.00 more than the Chevy 1500 UB, I have no way of knowing if it deserved or just Hummer Tax.

[Bebe]

Sorry forgot the second part of the question, the H2/2500/3500 Half Shaft plugs right into the H3 Unit bearing.

[DarkCharisma]

Originally Posted by Bebe

I guess that first we should make sure that we are talking about the same part and that we are using the term 'hub' to mean 'unit bearing'?

I am referring to the hub/bearing assembly, like this one:

http://www.rockauto.com/catalog/moreinfo.php?pk=1390766

Originally Posted by Bebe

I have heard this before, in this thread and others, but am always curious under what conditions they are weak. Not trying to disagree, but people often time say parts are weak yet offer no examples or experiences/solutions as well.

I have never had a problem with mine. I have been on the same hubs/knuckles for 116k miles in 5 years. About 90K has been with 35" tires, wheeling, Moab, Rubicon and Fordyce, along with many other Sierra Trails. They sound great when you give them a spin, don't leak, but at this point I do carry a spare JIC.

I understand that 38's are bigger, but I have seen H2's run 37's and have over 100K miles and have never replaced a hub (and they wheel them).

I replaced hubs on my '00 Silverado 1500, 4x4, twice; First was an OE unit that failed, second was a Timken unit that failed. This was with 35" all-terrains and daily-driving; I did little to no wheeling with it, aside from some dirt roads/trails to the places I'd go ride ATV's.

My '03 2500HD also had a failed hub/bearing assembly at 80k miles, although it did have 37-41" tires for a good majority of it's life--No wheeling, though. Daily driver, show truck and trailer puller. It was an OE hub that failed.

Originally Posted by Bebe

Maybe the H3/H2 hubs are different than the GM 1500/2500/3500? I know we had to modify a GM 1/2 ton chevy hub to work on the H3 we repaired in Moab (we had to change the wheel studs because the shoulders were hitting the brake rotor).

I also know I drove home to NorCal from Ely Nv (400 mile) with no front axles. We had no issues with the bearings. A couple of folks we talked to after told us NEVER to do that again

I don't know why they would be different, or why the GM version of the part would fail more frequently before the Hummer parts.

I know the H3 UB is about $200.00 more than the Chevy 1500 UB, I have no way of knowing if it deserved or just Hummer Tax.

I haven't a clue unfortunately if the GMT-800 and GMT-900 hubs/bearing assemblies are the same as the H3... I'd imagine they're different as it's a different vehicle platform, but again I don't have any facts one way or another.

Just curious. That seems to be the only point that I am sticking on, but if you and your guys have thought that out already, sweet. Ya'll have done far more than I have, so I don't really have a dog in the fight.

Keep up the good work. Looking forward to more progress pics and such.

[Bebe]

Originally Posted by DarkCharisma

I am referring to the hub/bearing assembly, like this one:

http://www.rockauto.com/catalog/moreinfo.php?pk=1390766

I replaced hubs on my '00 Silverado 1500, 4x4, twice; First was an OE unit that failed, second was a Timken unit that failed. This was with 35" all-terrains and daily-driving; I did little to no wheeling with it, aside from some dirt roads/trails to the places I'd go ride ATV's.

My '03 2500HD also had a failed hub/bearing assembly at 80k miles, although it did have 37-41" tires for a good majority of it's life--No wheeling, though. Daily driver, show truck and trailer puller. It was an OE hub that failed.

I haven't a clue unfortunately if the GMT-800 and GMT-900 hubs/bearing assemblies are the same as the H3... I'd imagine they're different as it's a different vehicle platform, but again I don't have any facts one way or another.

Just curious. That seems to be the only point that I am sticking on, but if you and your guys have thought that out already, sweet. Ya'll have done far more than I have, so I don't really have a dog in the fight.

Keep up the good work. Looking forward to more progress pics and such.

Well it may be worth some investigating. I think the GM folks might be interested in running the Hummer Unit Bearings instead of the OEM product. They already love our wheels.

Speedy, my BF just mentioned it could be the wheel offset? The Hummer H3 offset is 5.5". What is the OEM GM wheel offset?

Makes sense to me, if aftermarket wheels have less backspacing, then they could be adding more force to the unit bearing. Sounds like something worth looking into.

[Rot Box]

I just stumbled onto this one. Unbelievable craftsmanship can't wait to see how it turns out

[tjkj2002]

Originally Posted by Bebe

Well it may be worth some investigating. I think the GM folks might be interested in running the Hummer Unit Bearings instead of the OEM product. They already love our wheels.

Speedy, my BF just mentioned it could be the wheel offset? The Hummer H3 offset is 5.5". What is the OEM GM wheel offset?

Makes sense to me, if aftermarket wheels have less backspacing, then they could be adding more force to the unit bearing. Sounds like something worth looking into.

I generally replace at least 1-2 unit bearings on GM fullsizes each week,from 1/2 ton to 1 ton,stock and lifted with big tires.Does not seem to matter,also range from 60k-150k+ miles and some are on there 3rd or 4th unit bearing.Same goes for the idler arm and pitman arms before they went to R&P steering in '07,very big money makers for me.

GM even recalled many of those unit bearings in some states due to severe corrosion in the ABS sensor area causing some very unsafe ABS operation.Seems water get's into the bearing very easily through the ABS sensor and that does no good for the sensor or the bearings.

[Bebe]

Originally Posted by tjkj2002

I generally replace at least 1-2 unit bearings on GM fullsizes each week,from 1/2 ton to 1 ton,stock and lifted with big tires.Does not seem to matter,also range from 60k-150k+ miles and some are on there 3rd or 4th unit bearing.Same goes for the idler arm and pitman arms before they went to R&P steering in '07,very big money makers for me.

GM even recalled many of those unit bearings in some states due to severe corrosion in the ABS sensor area causing some very unsafe ABS operation.Seems water get's into the bearing very easily through the ABS sensor and that does no good for the sensor or the bearings.

Well then - there you have it, they must be entirely different unit bearings, I know the H3 has not had a recall on unit bearing, and I haven't seen anything about the H2 either.

Again since you have seen them in person, what size tires and offsets on the wheels are the most common?

Perfect that we have someone with experiences - Thank you for posting.

On second thought, since the unit bearing is not serviceable unlike a wheel bearing, I'm thinking 60k - 150K miles before replacement doesn't necessarily make them weak. Just a GM money maker.

I'm curious to know if the ball joints are service-able on the 1/2 ton - 1 ton GM Trucks. On the H3 you have to change the entire upper a-arm to change the ball joint ($300+), but on the lower 's you can replace just the ball joint.