heavy duty solid axle swap idea

[MaxPF]

my plan is to swap in the engine, tranny, and T case from a H2. that means bigger engine, better and tougher tranny, and tougher T case.

tranny in the H2 is a 4L65e, which isn't really any tougher than the 4L60e in the H3. I also don't think the t-case is much tougher. Besides, are there really any serious problems with H3 t-cases? Usually all we hear about is issues related to the shift module and/or plastic shift forks, both of which are fixable. Has anyone actually blown one up?

 

[ReconH3]

Problem with the H3 transfer case seems to be the casing and not the guts (except plastic fork). Mine exploded and I know of many others that have had the same problem.


"Ex Umbris Venimus"

 

[06 H3]

Isn't the aluminum casing exploding normally from driveline vibes? Seems common on basically everything that has an aluminum case. Seen it happen most on JKs and Chevy trucks

 

[High Five H2]

I mean the 6l80E and 6.2 from the newer 2's.

 

[06 H3]

What size tires you wanna run?

 

[High Five H2]

38" - 40". I figure if I'm going to do a SAS, I might as well go big for peace of mind.

plus 8 lugs axles are cool.

 

[MaxPF]

Problem with the H3 transfer case seems to be the casing and not the guts (except plastic fork). Mine exploded and I know of many others that have had the same problem.


"Ex Umbris Venimus"

Isn't the aluminum casing exploding normally from driveline vibes? Seems common on basically everything that has an aluminum case. Seen it happen most on JKs and Chevy trucks

I've seen aluminum cases break from driveline vibes as well. I've also seen the trailhousings of transmissions broken that way. Recon, do you know what makes the H3 cases "explode"?

I mean the 6l80E and 6.2 from the newer 2's.

Ahh, OK.

38" - 40". I figure if I'm going to do a SAS, I might as well go big for peace of mind.

plus 8 lugs axles are cool.

Something to keep in mind when shopping for axles: The "standard" 8 lug bolt pattern used by the big 3 up until the late 90's was 8 on 6.5". In 1999 (1997 on some trucks according to some sources) Ford went to 8 on 170mm. In 2011 GM went to 8 on 180mm, citing the need to maintain SAE standards with increasing GVWR/GCWR of their trucks. Dodge appears to still use 8 on 6.5". If you're looking at Chevy full floater rear axles, whether 10.5" or 11.5", 2010 is the last year of 8 on 6.5. Likewise, any D60 out of a StupiDuty will be 8 on 170mm. It would suck to buy a later axle, sling it under your truck, and find out your wheels won't go over the lugs

 

[ReconH3]

I really don't know what makes it explode. Mine did it when ORE took it to SEMA so I wasn't there to see what happened. I kept it for the guts as spares. It cracked where the two halves meet on the left side. Not near the rear slip yoke housing. Pics of others that I've seen where always around the same area. No internals where damaged so I'm guessing it's a design/production flaw/weakness.


"Ex Umbris Venimus"

 

[4speedfunk]

06H3...you might consider doing a C-clip eliminator and running chro-mo axles on the stock 10b. I see these mods a lot at the drag-strip, and I've seen some really crazy launches and fast times from 10-bolts. The C-clip eliminator doesn't really convert it to a full-floater but at least you would retain the wheel if a shaft breaks. Plus...upgrading to chro-mo should get you a worthwhile improvement in overall strength. I personally feel that the 8.6 is a pretty tough critter, and it might be worth modding your stock axle just to bypass all the fab/ABS/brake work of upgrading to something entirely new. After all...its a perfect fit, and its already there! I think the key to survival (with 37"+ tires) is to stick with the crawl. 6000 rpm ledge assaults will surely grenade a D44 or a 10b.

 

[06 H3]

Yea I might do that. The 14 bolt is an option in the back of my mind but I dont really do axle swaps till I have an issue, like 4 front diffs! Lol I'll need to break the 10 bolt before I even consider it. I think they get a ****ty Rep because a 10 bolt in the rear under a blazer heavier then us and a 454 is not much better then the AAM 7 up front.

 

[High Five H2]

good to know about the bolt pattern. thanks.

 

[4speedfunk]

Yeah. The late-model 8.6 axles seem to have a better rep than the 70s/80s-era 8.5 versions. (or maybe they just don't see the abuse nowdays). Regardless, GM upgraded the 10b bearings in 2000 and again in 2009. I just did a set up on Geno's 2009 8.6 and the inner pinion bearing is huge! The stock H3 shafts seem pretty beefy compared to older 8.5s. The fact that GM has left the ring & pinion basically un-changed for 40 years means they must be pretty confident in its performance. I think the rest of the axle has been beefed over the years, and its nice to see GM actually improve something, for a change.

I'm not a 10b expert but I've owned at least 6 or 7 of them in various forms and I've never been disappointed in any of them. I did blow up a few of the smaller (7.5") versions in my 79 Malibu but, eventually I swapped to the 8.5" version (from a Buick Grand National) and never had any issues afterwards. A 10-bolt will never be a 14-bolt...but, its a real good compromise. Light-weight, low-cost, minimal drive loss, parts availability...I really don't see a reason to upgrade unless you start to get "throttle shy" when wheeling. We've both been there before with the front axle and I hate that un-easy feeling of "Is this going to be the trail I walk-home from?" -LOL Wheeling without confidence is no fun.

 

[MaxPF]

FWIW, the new Chevy half ton trucks with V-8 engines are getting a 9.5" rear end as standard equipment. The "max trailering package" gets a 9.76" rear end. The 9.5" appears to be the same ol' 9.5 axle that's been used for years. Not sure if the 9.76" axle is a beefed 9.5, a Dana 60 (GM likes adding that .01 to new axles for some reason, even thouth the ring gear size is unchanges), or a new AAM axle.

I wonder why AAM increased the size of the inner pinion bearing in the 10b? The old pinion bearings were already the size of Dana 60 inner pinion bearings and never had issues.

 

[High Five H2]

is that 9.5 a 12 bolt? how do they compare to 10 bolts?

 

[MaxPF]

is that 9.5 a 12 bolt? how do they compare to 10 bolts?

The 9.5 has a 14 bolt cover, but it's nothing like the 10.5" 14 bolt. It's basically a 10 bolt on steroids; it's still a c-clip semi-floater, but it has bigger bearings (including outer shaft bearings), bigger shafts (33 spline vs 30 spline) bigger carrier with bigger spider gears, and of course a bigger ring&pinion. This is the axle that the H2 uses, and has been used in light 3/4 ton GM trucks over the years. It nicely bridges the yawning chasm between the 10b and the 10.5" 14bff. However, it's still a semi-floating axle so a broken shaft will park you until you fix it.

IMO, if you're willing to go 8 lug you might as well get the full-floater since it's a superior axle in every way. OTOH, if you want to stay 6 lug, then these new axles may be an excellent upgrade option. They are supposed to be an inch wider than the previous axles, so hopefully they aren't too wide. Expect to wait a few years before they become available in the parts yards thoughj...

 

[MaxPF]

06H3...you might consider doing a C-clip eliminator and running chro-mo axles on the stock 10b. I see these mods a lot at the drag-strip, and I've seen some really crazy launches and fast times from 10-bolts. The C-clip eliminator doesn't really convert it to a full-floater but at least you would retain the wheel if a shaft breaks. Plus...upgrading to chro-mo should get you a worthwhile improvement in overall strength.

The disk brakes on an H3 will prevent the shaft from walking out if it breaks, so a c-lip eliminator doesn't really offer an advantage. In either case you cannot drive off a trail with a broken semi-floater axle shaft.

Also, there are no chromoly shafts for semi-floater axles. The upgraded aftermarket shafts are made from 1541 steel, and they claim a 25% increase instrength over stock, a claim which I find dubious. Maybe they have better fatigue resistance? In any case the reason you don't see 4340 shafts for semi-floaters is because the shafts have to be surface hardened where the outer bearing rides, and 4340 isn't able to be case hardened. That's the same reason you never see 4340 ring and pinions. It would be possible to forge a semi-floater shaft from 4340, machine the bearing/seal surface undersize, and press on a sleeve made from a suitably hard steel for the bearing and seal to run on. Nobody that I know of makes such a critter though. Another option would be to forge the shafts from a case-hardenable high strength steel. About the only option for that would be Ferrium C61, which was developed to upgrade the gearboxes in military helicopters so they could run higher HP turbines. Some gear company did make ring and pinions out of this steel for Score off-road racing, and they claimed to last 4x longer than gears made from 9310. The main drawback here would be cost - the stuff is very expensive. I'm guessing the reason nobody makes such shafts for semi-floaters is because virtually all potential customers simply swap to larger axles instead.