Re-Gearing a M1009's axles

[niferous]

Does anyone know how hard this is? It's something I've always wanted to learn how to do and I know I can get the parts and do it a lot cheaper than taking it somewhere. I'd like to change out the gearing to a 3.73 gear and leave the gov-lock/detroit in the rear. If possible I've thought about putting something like an Auburn limited slip in the front. If anyone knows how to do this or can recommend a good place to learn I would appreciate it.

I called a local drivetrain shop I trust and they want $625 for each axle. That's re-gearing them and then replacing all the bearing. I figure if I do it myself I can POR-15 the axles and also install a 2" lift kit while I am at it.

 

[Westech]

It is very ez but to do it correctly you do need some special tools. you will need a dial indicator and a torque wrench that s in Inch pounds.

BUY A Chilton repair manual!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[4bogginchevys]

if I were you...I would get gears from a junk yard(there's nothing wrong with that!)
ditch the gov. loc if you can...they too have a service life and I found the end of it atleast twice on 1/2 ton running gear....anything with clutches is good, just get rid of the pins/springs/etc. Make sure you replace the crush collars on the pinion of each!

BTW, if you offroad this truck and it has oversize tires than you may end up breaking axle-joints....with a posi in front that is, been there done that!

 

[nhdiesel]

Just my from years in the auto repair business and many more years in the 4-wheeling hobby (including building and repairing them), but the Detroits are the way to go. Standard limited slips (with springs and clutches) work O.K. when new, but quickly lose their effectiveness. They also won't give any real traction for anything except snow driving, because they allow slippage. They are the more "street oriented" option, and generally drive nicer on the street, but if you are driving a bare-bones military vehicle already, and have no complaints about the lockers, then I would keep them. Yes, they can wear...but generally they far outlast a limited slip for useful life, and can last for many years and easily 100-200k miles if the fluid is changed regularly (every 30-50k miles at least, more if the vehicle is used hard).

For gears, there isn't much reason not to buy new for your truck. You can get quality ring & pinion sets pretty cheap, and they aren't all that hard to put in. Patience and attention to detail is all it takes. About the only special tool needed is a dial indicator, and you can pick one up for $25 or so. It won't be a high quality one, but fine for checking ring gear backlash, and you can use it to check brake rotor runout as well. The inch-pound torque wrench is nice, but not entirely necessary.

When the time comes hit me with a PM, I can walk you through the install process. For parts you'll want to price out a ring & pinion set and master setup kit for each axle. Make sure the kits come with new ring gear bolts...they are almost always 1-time use. You don't want to go through all this and have the bolts loosen and ruin the new parts. Make sure the setup kit comes with bolts, carrier bearings, and shims.

One thing to check on- most differentials have a split where a different carrier is required for different gear ratios. You'll want to find where that split is for each of your axles. You may get into having to buy new carriers (which will include the rear locker). And I'm willing to bet that estimate you were given doesn't include a new carrier, because thats about the price range for a simple ring & pinion swap.

The price given to you really isn't all that bad once you start adding up the parts. A quick check of Summit Racing shows $155 for gears for your front axle, add in $100 for the install kit (a Superior Gear one shown had the bolts, bearings, & shims), then add in misc. parts like RTV for the diff cover & gear oil and you are up to almost half of what you were quoted just in parts. If you have to swap carriers, it will get much more expensive very quickly.

The Auburn is a good choice for the front, or else a Detroit Truetrac. The Truetrac is a good compromise between a limited slip and a full locker. I put one in the rear of our Jeep Cherokee when it was my wife's daily driver, and when combined with the full locker in the front, was still able to so some pretty serious rock crawling even with 31s. Pics of it are HERE and HERE.

Jim

 

[1stDeuce]

I second the aubrn/true trac for front use. They're both great with tires up to about 33". Bigger than that and you're not able to tell as much that it's working, though it really still is. A little brake pressure helps them lock up better if you're getting twisted up... (Both respond to torque, not slip, so adding torque through the diff increases bias rate.)

For the rear, I might suggest checking old junkyards for a 70's 1/2 ton chevy with a 12 bolt axle (8-7/8" ring gear). It's a bit more HD than the 10 bolt (8.5" ring gear) in your 1009, and can be had with the correct gears for cheap compared to rebuilding a 10 bolt. It also has heavier brakes, which is nice! To keep on the cheap, drop in a Lock Right or something like that. Same function as a Detroit, but a lot cheaper, and they work with c-clip axles and the stock open carrier. You're not going to break one with a 6.2. The Detriot will require you to switch to c-clip eliminatorys, which is not a bad idea, but adds expense. Alternately, an early to mid-90's 1/2 or light 3/4 ton with the semifloater 14 bolt with 6 bolt hubs might be easy to find thanks to CFC. It's a little heavier than a 12 bolt even. (9.5" ring gear.)

C

 

[84cucv1ton]

just a thought. what about 8 lug 3/4 tons? i think some came with 3.73. i know they have 4.10s got them for a friend for 300 complete.

 

[Cucvnut]

3/4 ton running gear is fine to use as a upgrade for a blazer. the 14SF is a good axle. and a 10 bolt is ok up to aobut 35's ( i ran my burban with a 10 bolt on 37's and never has a problem.) but you need to switch to 8 lug rims

 

[niferous]

I found a guy selling an 8 lug front and corp 14 rear with 3.73 gears out of a 3/4 ton Suburban listed for $500 on Craigslist. Would these fit? Also if not a Dana 60 what did the 4x4 3/4 ton Suburbans come with?

 

[84cucv1ton]

well a corp 14 rear. you mean a full float? that would be a 70s burban i think. earlier years had dana 44 fronts later years have a 10b with 8 lug from the knuckle out. if its a 80s burban like mine it will have 10b front and 14b semi float rear. hope that helps

 

[Cucvnut]

its a good deal but i would offer him 450 and see if it takes that.

 

[nhdiesel]

I've seen newer 3/4 ton Suburbans and pickups with the FF 14-bolt. I think its a coin toss which one you get. Check the spring pad mounting location width between the rear axles. Most GMs are the same, but there were a few that were different. The fronts should bolt right in.

For the front, if both are 44s (the blazer 1/2 ton and the Suburban 3/4 ton) save your old axle for parts, because many of the parts are the same. The housing & axle shafts are the same, as are the manual hubs. If that Suburban has auto hubs, don't worry...you can put your manual hubs right in.

Jim

 

[Cucvnut]

most 2 wd 3/4 ton burbans got the 14ff the 4x4 ones got the 14sf axles

 

[niferous]

It's a full floater out of a 1990. One thing that makes me gun shy about putting new axles in is that I just bought new 15" tires for this thing! If I go get 8 bolt axles I have to switch to a 16 rim and then buy new tires all over again! Plus find some CUCV rims! Maybe I can use the 32" tires on my FJ60 Land Cruiser. Hmmmm decisions decisions.....

 

[Recovry4x4]

You can put 15" wheels on the 3/4 tone stuff but it will require some caliper grinding.

 

[4bogginchevys]

the 12 bolt 8 7/8 axle is way better than the 10 bolt in my opinion
carrier split for 44/10/12 bolt is 3.73 and down.....4.10 and up
carrier split for 14 ff is 4.10 and down.....4.56 and up

When I destroyed a set of 3.73s 4 wheelin'(44/14bolt) I found front and rear 4.56 at the junkyard.......ring/pinion and yokes for 96.00, because they had been previously set up they were close and all I had to do was move around existing shims, and/or use donor shims from my donor gears. All in all I was installed for 150.00 easy...as long as I can find gears that I want used I will never buy new, it's not only a waste of money but it ends up more work by the time your all done! New ring gear bolts are cheap and can be purchased separately for 10-15 $.

BTW, knuckle out is the same on 44/10 bolt including stub shaft....just remember that there are 2-3 different spindles out there and they require different bearings/races/rotors...I know it sounds contidictory but you'll find out what goes with what real easily. Good luck