How strong are 10 bolts really?

[Mohawk Dave]

Hi All,

I ask b/c I just picked up a M1009 with the 10 bolts, 6.2 diesel, and t400. I will be swapping the d60/14B w/4.56s gov-lock & L/S from a M1028 when I save a little green.

But until then, I have the M1009 on 37 HMMWV tires, and it will see the southern california desert when we race- (we race desert trucks-this is not a race vehicle obviously) and up the backside to Big Bear, which is, I think moderate trails- rocks the size of fullsize ice chests give or take.

I know I can't haul donkey down the whoops, but mainly I'm asking what will break/bust/explode on the 10B and under what conditions on the rock trails. i.e. all weight on one wheel? vertical climbs? etc...all the above?

we run 10 inch big dogs in all our desert trucks w/ 40 splines, so I'm really inexperienced with the 4x4 stress and abuse and the 10B in general.

I will need the 10Bs in working order to swap into the M1028 to drive/sell it afterwards.

Thanks,

Dave

[blazerboy85]

they arent strong at all. i blew the carrier completely in half on my blazer by doing a 2000 rpm drop with 33's. they most likely will not last long with the 37's but if you baby the truck and leave it open front and rear you might be able to get by for a little while. hell even the 10 bolt in my STOCK 92 silverado is starting to go, and all i do is drive fast. maybe a break stand here and there.

[_Stucky]

so which axle are you concerned with, the front, back, or both. my 91 k5 has the 10 bolts, which have both grenaded. the front busted in a shallow creek bed with 31s. i broke the ears off the passenger side shafts , inner and outer. but i upgraded to chromoly shafts and 35's and havent had a problem since. that was about 3 years ago. the back blew up while i was driving down the road, no recent trashing, no recent burnouts or mudholes or anything. just driving. the center pin that holds the c clips in fell out and shot like a rocket out the back of the cover. it put a perfect circle hole in the cover and was never seen again. i came to a screeching halt. i think i had the 35s then. was fixed for free with the differential and cover from a van we had around, but i lost the factory limited slip for an open carrier. currently awaiting my sf 14 swap with 6 lugs, 3.73 gears, and disks.

what im trying to say is that 37 inch hummer tires may be to much for the ten bolts

[bscman]

I come from the 1st gen Camaro/2nd gen Nova scene...12bolts are getting too hard to find, so the go to axle is the 8.5" 10-bolt. With a good carrier and aftermarket axles, there are MANY 10.5" tire cars running into the 10-second quarter mile, and lifting the front end on launch.
But these are cars ~3,000lbs with driver.

That being said, 4-wheel low with a 4500-5000lb rig, and big heavy 37" tires is NOT kind to the same axle.

My '86 with 35's pretty much only sees gravel roads, gravel pits, and riverbeds but has been through two rear shafts and one carrier.
The first axle went out on the street when my gov-loc locked from a stop sign/90* turn (light throttle).
The locker went out the week after I replaced the axle...on the street...from a 1/2-throttle take off from a stoplight (no tire spin). The second shaft snapped when trying to do a "poser" flex shot on a rock that was maybe 14" tall.

I just got done swapping in a 6-lug 14 Bolt SF.
Axle cost me $200, but I had another $200 into it by the time I got new seals, axles, brakes, and perches. If you compare shaft diameter and carrier/ring gear size between the 14b SF and a 10-bolt, it is a HUGE upgrade that won't break the budget and you can keep it 6-Lug to match the front.

As for the front axle...mine is still going with stock shafts and new joints.
Keep it open, and if it gets a little bound up with the wheels turns, you better back off and try another line...and keep the diff open!
At least if you snap a front, which you will, you can probably drive out.

[JK3078]

When I first built my truggy (based on a 85 suburban) I used the stock axles (welded) front and rear on bald 35'' Interco SSR's. Not long after putting it together my kid was trying to do a "burnout" on the gravel road by our house and the rear ten bolt snapped bolth axles off right at the splines! Mind you this rig weighs 3700 pound and has a stock motor/trans.
After that fail a swapped in a 12b from a 76 pickup (welded) with 4.10's and a six lug converted 10b front (welded) from a 3/4t 79 sub., 4.10's. I have had zero problems with the rear axle, currently on 15x38.5 Boggers, and only occasionaly lose a u-joint in the front and I wheel the rig pretty hard as often as I can afford to.
My dailly driver 85 GMC sub is all stock with 32x11.50's, 130,000k(ish), and has never seen anything other than very light offroad use and the rear is getting pretty lose. I know its on borrowed time so I have a 12 bolt waiting for it to finish giving up.
To the OP, I would say from my experience running that axle (10b) in the rear of that rig (heavy) with 37'' tires is not going to last long if you wheel it at all.
Parts that will fail in the order of most likely to least:
1. Carrier/roll pin/spider gears (x2 for gov-bomb axles)
2. Axle shafts
3. Ring and pinion
4. The housing its self (bent, broken, spun tube(s))

[Mohawk Dave]

Thanks guys,

I knew they weren't strong. I just didn't know the weak link- besides the whole thing. I'll just take it a little easy until I get the swap done.

Thanks again for all the input.

-Dave