What is it within reasonable limits, anyone know? What starts to break when stuff does, I'm guessing front CV joints.

Without Rubbing is 38" although I have heard that non turbo diesel H1's do rub with 38" while offroading...

The NA doesnt have the 3/4inch bodylift like the Turbo.
What starts to break? Halfshafts, may be TCase, all depends on the situation, and driverstyle.

I have heard of numerious half shaft/CV joint problems... also steering components(pitman, tierods, ball joints, etc) wear out... Also have heard of tcases and transmissions failing but the Geared hubs and diffs are solid.

I agree with all the above -- having the brakes on the diff plus the added torque from the geared hubs means more stress on the cv's. Adding more unsprung wt/spinning mass you have to be carefull how you drive the truck or you'll be breaking stuff. Most who go over a 40" tire usually uprade to the 12k lb halfshafts (vrs the stock 10,300 lb shafts/cv's). Many run 42's on their trucks (with 2" body + 2" susp. lifts) but end up changing most suspension components more often (the idler and pitman practically after every other run). You can't get something for nothing.

I think Injun and I have discussed the following gobbley gook in the past:
I'm currently running the 1 piece steel wheels (47 lbs with lugs and hd ctis guards) with 37" irok radials (89 lbs ea) which is 136 lbs each wheel. That's actually a lighter than stock combo (runflats removed) but still alot of mass out there spinning around.

I want to get 39.5 iroks (the bias are 85 lbs, radials are 97 lbs) on my 2 piece steelies with internal beadlocks and full wheel protection (a 70 lb combo) for a spring/summer of abuse and carnage. If I did my math correct -- probably not -- I'll be adding 19 lbs/wheel with the bias (155 tot), and 31 lbs/wheel with the radials (167 tot). Something about crossing the 160 lb mark makes me nervous with stock halfshafts as the stock 37 mt's on steelies with runflats were about 160 each from AMG.

We weighed twopiece steels, and MT OZ, and stockbeadlocks, was about 140 lbs a piece. Cepek rims, and BFG MTs come in at about 110 lbs.

yeah that stuff is heavy -- I forgot mention that the stock 37' mt is 75 lbs, the 2 piece runflat I removed was 35 lbs (and as I mentioned the 2 piece steelies in my garage are 43 minus the lugs and the amg beadlocks are 15). I don't have the numbers on the 1 piece runflats. I love the cepek wheels and hope to have some someday (when I get tired of vibration at hwy speeds).

Cepeks, and BFGs, is probably the best ridequality improvement. RTC has superior customer service as well. (G.T. Inc.)

depends on how you wheel...

the stock rim with the gsa tire combo was FAR heavier than my swampers/eagles. I think the 37 gsas were 80ish lbs each.

and these new 40" boggers and stazworks beadlocks are RIDICULOUSLY heavier than the swampers or gsas. Heck the rubber alone tips 115lbs.

with any heavy tire....if you tap the brakes with a wheel up in the air spinning and youll snap a shaft like it was a toothpick....those are hands down the weakest point in the system.

that said...if you are locked front and rear you should never have a tire "spinning free" given only one is off the ground.

We have built straight axle with hummer gear hubs several times.
We even have available 4340 guarenteed outer joints.
In the axles we build we use a wheel break setup.
If you are breaking shafts from hitting the breaks could a wheel break conversion help?
Also if the shafts are breaking we could build you a set of shafts that would be guarenteed. Just a thought.
I am not trying to pimp my stuff now but think either a bullet proof shaft set or wheel breaks may fix the issue.
On another note we have built wheels for several H1's runnig 40" tires

I am thinking of getting a H1 for my self to try a break conversion and a bolt on rear steer conversion we are working on.

John

does that mean my wheels are on the way? =)

(brian in fl)

and yes...tons of H1 guys go to the 12k halfshaft setup...but it requires quite a bit of modification to the existing truck as they use different ends from the 10k shafts/hubs/diffs.

if you could make an "unbreakable" shaft that used the existing 10k spline ends...id think you would have quite a few buyers.

another downside to hummer halfshafts is there are 3 different types for each truck.

the rear halfshafts are the same...but two different lengths are used in the front as the diff is offcenter (and both are different from the rear).

rubberduck4x4 came out with a front diff centering kit that allows you to use a single hs for all 4 corners...certainly on my list of things to do!

the bolt on rear steer sounds interesting.

It really depends on how you wheel and what shafts you are running.

I used to run 38 SX's with no lift, if your front springs are in good shape, no rubbing and I wheeled it hard at Tellico and other trails and only replaced one shaft in 3 years. The CV was cracked but not broken, I wheeled it for a year like that and when the crack started to grow wider, I replaced it.

I then installed a 2 inch body lift and 42 Iroks and moved to Alaska, I broke 2 more shafts in a year, one climbing a hill and the other simply turning around although it was 20 below and I have seen many rigs up here snap shafts like twigs in subzero temps, the extreme cold makes them brittle.

All broken shafts were the original 1993 light duty shafts with lot's of miles.

There are 3 levels of strength for halfshafts, the original 1985-1993 light duty shafts, the 1994-2003 heavy duty shafts, and the 12K/Alpha shafts.

I would be very interested in unbreakable shafts.

As for the pitman and ilder, the Hummer Power steering is very strong, hell it is designed to turn 37's from the factory. I have noticed that if you get the wheels in abind and you force the steering wheel, something will break or bend, it is better to back up and apporach at a different line. Som install the AGR setup with great results. I personally haven't done so yet, but I have been able to wheel mine for 5 years now with no steering issues at all.

I agree with all the above -- having the brakes on the diff plus the added torque from the geared hubs means more stress on the cv's. .

actually the gearing from the portal protects the cv by the ratio........ so if they are 1.7-1 the cv is 70% stronger than if it were 1-1

cheers, serg

good thing its 2:1 then! =D

oops, I guess I was backwards -- I was thinking that stopping a spinning 160 lb tire with the 2:1 hub would place more torque on the cv's. 42's here I come!

rb

Using common sense will stop all of that "spinning in the air and hitting the brakes hard" type of breakage. 42's are manageable with the use of some brainpower. Hell, you will need to turn up the injection pump to be able to spin the 42's.

The halfshafts are about the same strength as a Dana 44 shaft, but like the other guy said, it can handle it because of the gear reduction at the wheel. If there were no gear reduction at the wheel, they would last as long as a dana 44 shaft with 42's.

ask your self this what has more torque.... 1st gear high range or 1st gear low range????

is a propshaft subjected to more torque than the axles on a rig??

so gearing produces torque, having the portals at after the cv mutiplys the torque........ AFTER THE CV!

cheers, Serg

I was kidding about the 42's -- too big for me. And yes, some common sense and finesse will take care of the spinning tire problem, but that's still alot of mass out there. I don't think I'd go over 39's -- plenty big and I still need to fit in garages. I know several guys who run the 42's and love them, but they've had to upgrade shafts and steering (the stock steering handles the 37's fine, but any bigger and there's trouble). I haven't broken a shaft from btm'ing (yet...knock on wood) but the rear detroit has bit me in the arse a few times over the years.

i had swamper 39.5's on my 96 and diddent have any problems.

i had swamper 39.5's on my 96 and diddent have any problems.

that's why I don't want to go over that size.

if you could make an "unbreakable" shaft that used the existing 10k spline ends...id think you would have quite a few buyers.


I for one would definitely be interested in such a product if one was ever made!