10bolt front diff tech

[Schwarttzy]

Hey I'm up for building it with you and I live within driving distance.

I think have just found myself a 10 bolt too, was going to be turned if for scrap just got to check that it is right. I have been doing some research and decided that I would like to start a build thread in my sponsor section covering everything with point of selling the parts for someone to build their own... assuming this all works out.

They particular axle we are all looking for came in Blazers and Suburbans, basically the K series which is the K-10, K-20, and K-30. Careful though, some of the years came with Dana 44s which won't work and also some of them came with 30 spline 10 bolt axles. Now if you have trouble telling the difference from a 44 and 10, just look for two ninety degree square tabs on the bottom of the axle housing. The years that work for us are 1976 all the way 1987, no other year will work for this project. So if you want find yourself an axle easily, go to http://car-part.com/ and pretend your one of those vehicles.

 

[06 H3]

I know distance can be an issue with shipping but I can modify anything that needs to be done as long as the machining is done I can help. I can weld or grind stuff off and redo it in case there are install issues. I have the rancho but Kyle is just a few minutes from me and when he has his H3 I can test fit it on his stock setup. So if you don't need testing done locally I can do it.

I'm pumped! If this goes through I think this will compliment my setup nicely.

 

[4speedfunk]

It would be nice to know if this would fit in a stock H3. The Rancho kit definitely gives more wiggle room, and I'm 99% sure that would be no problem. At this point the only real issue I see is the mounting ear on the snout of the pumpkin. Because the yoke shifts slightly to the driver-side on the new larger axle...I think trying to re-use the stock crossmember bushing and mount may be a problem. At first glance, it looks like the pinion will be directly above the stock bushing (and not off to the side). Considering how these bushings are often junk anyway...I was thinking about welding the ear onto the other side of the snout. Then when you get the axle in place...simply drill a new hole up thru the crossmember to align with the new mounting ear. I'm sure we could come up with a new bushing...skateboard wheels, hocky-pucks, or something.

Schwartzy...I think this axle only came in K10 models. I've never seen or heard of an 8-lug (K20 or K30) 10-bolt. Whatever the case...they are super common and super cheap. Also keep in mind that the later 30-spline models will work too. I'm guessing that 90% of guys that would want to do the conversion would want a locker...so in most cases, they would dump the stock 30-spline open diff anyway, and replace it with a new 28-spline locker. Additionally, most guys would want 4.56 and lower gearing...and that usually requires a new carrier too. The stock 2.73 and 3.08 carriers don't have the offset needed for lower 4-series gears. So, since most folks would install new gears and a carrier...it doesn't really matter if you start off with a later 30-spline version. The CUCV Blazers (military diesel Blazers) came with this axle in a 3.73 ratio...I think that might be the lowest factory version, which is still too high for our use.

As far as selling parts for this? Well...there is only one part: the housing. You might consider selling a "prep service" that chops, and converts the full-length housing to AAM-7 dimensions. Thats sort of the only opportunity I see to make money off it. Prepping the housing will not be a weekend warrior project...it will take a full-tilt machine shop.

06H3...The finished axle is very small. It can easily be mailed UPS.

 

[MTUH3]

To the 3 amigos and amiga.... Well done so far. I am keeping up this is looking good

 

[atvspeed4]

I might be willing to test this. I also have the ability to turn/ fab a solution for the snout bushing/ I have the wire to weld to the snout as well. We were going to do this ourselves but did not plan on it till end of January.

 

[Schwarttzy]

@4speedfunk - I'm not looking to make money off this project, just would like to offer something so all anyone would have to do is find a 10 bolt axle, cut it to size, weld some parts, and then stuff it with some gears. Your right about the spline count not being necessary, I'm not sure why it slipped my mind that you could easily change the carrier over to the correct spline count when you re-gear.

I convinced that this won't be much harder than when I cut off all the brackets on a Dana 35 and welded them on to a Ford 8.8.

 

[06 H3]

CJ, How much wider is the pumpkin comparing it to the 8.5? Will the 8.5 be a tad more inboard so it keeps the pass side shaft from going out further then the stock setup?

I know its kinda confusing if you dont get it I will try to re explain it.

 

[4speedfunk]

06H3...not confusing at all. I totally understand and yes, it will sit further inboard. The PS face will be at the same location, so the stock half-shaft still fits....but the pinion will be around an inch further inboard. The tube on the DS (and the shaft inside it) will need to be somewhat shorter too, for the same reason.

Schwartzy...I'm in complete agreement. This is a junkyard build and I think it should stay that way. However, the machining involved is a tad intimidating and it might be tough for the normal guy to get it done. If you were to take one of these 10-bolts to a machine shop, and they weren't familiar with what you wanted...it could get real expensive. I got some connections, and I have the resources to back-up a truck full of these axles and chop em down like an assembly line. Just like everything, when you do ten of em in a row...you get real good at it, and its also much cheaper than one-zies and two-zies. I'll know more Monday what its gonna take to get it done.

 

[Medic_Morgan]

This is getting interesting def gonna follow this one and take notes


Sent from my secret lair bwaaahhahahahah

 

[jakesz28]

I just saw a 8 lug 8.5 ten bolt on the quad cities craigslist a couple weeks ago. I also believe a friend had one many moons ago. It would have been in the 80' s. GM was using the axles up.

 

[06 H3]

Alright, cool! I'm stoked to see how this works. Either way I'm all in.

 

[backcountryislife]

Alright, cool! I'm stoked to see how this works. Either way I'm all in.

You won't regret it... being able to gear down alone is worth a ton. After swapping to 5.13 on mine, the way I see the trail has changed hugely. The amount of control changes everything.

Why couldn't some of the thing I'm seeing happening right now have happened a few months ago???

Sent from my A200 using Tapatalk 2

 

[06 H3]

idk man! We can never deny you pushed some of these mods. The steering rack brace by dwaine @ preferred chassis was probably pushed from you breaking rack after rack. This was done once before and it came up in discussion on another thread and I created this thread to push it. Being able to run a locker without too much fear now is a huge gain. Most of the heepers I know say a front locker is DRASTIC in performance.

After this is done I will start working on front flex as I have the rear flex covered.

You really helped us out and calling out the weaknesses. So, once we get all this done I plan to drive to CO and do some wheeling, lets see if I can keep up and not breakdown. Hopefully this summer...

 

[4speedfunk]

Before getting too deep into this, I did some surfing around to check on locker options. Because the H3 has traction control and ABS...I think its important to use a selectable locker (vs. an automatic unit), in the front axle. Spools, lunchbox lockers, detroit lockers, and limited slips are all OUT as far as I'm concerned. Additionally, I want to make sure that whatever selectable I choose...it operates in open (single-track) mode when dis-engaged. This will ensure my electronics will function normally. Focusing on a few major brands, here's what I find out about the 28-spline (early version) of the GM 8.5" 10-bolt...

EATON These guys make several lockers...the electric E-locker being the only one I'm interested in. This unit does operate as single-track when un-engaged. However, all of the literature regarding the 10-bolt says that they only offer the 30-spline version. Not good. They do make a 28-spline version in a spool and a posi...but neither of these is usable IMO. So these guys are out.

ARB These guys offer a 28-spline Air locker, and it also operates in single-track mode when off. So thats an option.

AUBURN These guys offer a 28-spline E-locker but, it operates in limited slip mode when off. So thats out.

OX I found this by accident. Looks like nice stuff...made in USA. I'm familiar with their U-joints for many years. They do offer a 28-spline selectable, and you have several choices for how to control it....electric, air, cable, or manual. I am not sure on how it functions when dis-engaged...waiting to hear back from them.

Thats all I have found. Most of these are 2.73 offset, so a thick ring gear will most likely need to be used...not ideal but, do-able.

 

[Schwarttzy]

I'm going to go with the Detroit TrueTrac partly because I don't want to have wires or cable running around my vehicle, but mainly because it is unbelievable when you see this gear base limited slip pull you straight down the road in icy conditions. They're also quite inexpensive too along with having no problem with the ABS.

If you happen to work the brake just right you can lock this thing up with a tire in the air too.

 

[4speedfunk]

I have yet to see any sort of automatic full-time locker installed in an H3...seems like it would play hell with the electronics. You'll notice that the factory lockers are only functional in 4LO-lock, (when the electronic VSS is defeated). Also notice that the VSS is only functional in 4HI (when the lockers are defeated). GM will not let you do both...so there must be a reason. The TCS, VSS, and ABS rely on signals from each hub to tell the computer how fast each wheel is spinning. Any drag between left & right wheels (limited slip, posi, detroit, etc.) would most likely give the computer a false indication of what the vehicle is doing. The only way to get an accurate reading at each wheel, is if each wheel is free to spin independently from the others. That requires a single-track (open diff) or a selectable that operates as a single-track when its shut-off. I'm guessing GM chose the Eaton selectables for this reason. When they're OFF...they're truly OFF, and have full 100% slip from left-to-right. If this weren't the case...seems like the H3 would come with an auto-locking rear diff like all the other GM trucks! The fact that it comes with a selectable should tip us off that it needs open diffs for the computer to work correctly. I got no real proof of this...strictly a hunch on my part.

Also, don't forget....its still an IFS. Not sure I would want an automatic full-time locker engaging and dis-engaging all the time. Electronics aside...lockers are very hard on the rest of the front axle. I think a full-time locker on an IFS is a huge no-no. Its something that I would only engage as a last resort, before breaking out the winch. For these reasons I'm going selectable or open diff on mine. Hell...I might even buy some thick 4.56 gears and install them on the stock 2.73 single-track carrier.

Go ahead and install the True-Trac...I'm curious to see how it works with the puter. They're certainly cheap enough, that if you had problems you could swap it out for something else.

 

[Schwarttzy]

A Truetrac locker is in a world of it's own, it's nothing like a limited slip or a full locker in any respect of how they operate. Truetrac lockers operates strictly based on torque, and sends the torque to the appropriate wheel. However when the locker sends torque to the appropriate wheel, it does not make that wheel or the other one speed up or slow down. Because wheel speed is unchanged, it should have no effect on any of the sensors, also this is why it is so amazing on icy roads.

There is no drag, it never fully locks up, has no effect on turning, and you'll never feel it engage or disengage which is exactly why I want this locker.

(looking for a video right now.... can't seem to find it)

 

[MTUH3]

Sounds like the Ford Wavetrac

 

[Schwarttzy]

Sounds like the Ford Wavetrac

At a quick glance it looks exactly the same, just double the price for some reason...

 

[atvspeed4]

I always wanted to run a tru trac like the h1. Remember that the 03+ h1 had traction control and a torsen diff. But.... it had a different bias ratio than the older versions without traction control and did not work as well. So its not just a matter of running a limited slip with traction control but also what the bias is. I'm going off on a limb here but the traction control might work great with this limited slip. In my friends h1 you apply brake pressure to "activate" the wheel with traction. Our traction system already applies brake pressure on its own. But thats all theory...

 

[5gn-h3t]

You guys are a bad influence...

:wink:

 

[06 H3]

**** that pile of ****!

 

[Schwarttzy]

@5gn-h3t

Is that photo telling me that I can drop the front axle without removing the front drive shafts... because that would be freaking sweat!

 

[4speedfunk]

Get that gay-ass thing away from your truck!

 

[5gn-h3t]

Schwarttzy - Pop the cv's free of the diff, pop the upper ball joints loose (unbolt the ABS wire), cock the spindles out, drop the diff.


Edit - There's a driveshaft, cross-member, and UCP in there somewhere too. Lol.