Gearing m1008 axles

[t4billl]

To change to 3.55 or 3.73 gearing does carrier bearing need changing and has anybody done this

 

[JohnFire]

Let me know what you find out. I am looking at doing the same thing. I have found ring and pinion gears on ebay for around $200. That is all I thought I would have to change. My truck came with brand new tires and I don't want to add a lift or buy new tires. Driving 55 and having it scream at me is not my idea of fun. I was looking at 4.10 or the 3.73 since I want to keep it for towing or hauling if possible.

 

[CCATLETT1984]

to change the gears to a numericaly lower set, you must change out the carriers in both axles as well, and remember in the rear its a detroit locker. your looking at over $1000 to change out the gears. thats why many put a mild lift on the truck and larger tires to drop the ratio. with my 38" tires its like having 3.73:1 gears while still having my stock gearing.

since you dont want to lift the truck or change the tires out, look for the 4.10:1 & down carrier for the front dana 60, and you'll have to decide if you want to spend the money for a detroit locker in the rear again or just get an open carrier for it as well.

 

[Angus1]

I dont think you have to change the Carrier till you get to 4.10 or lower gear ( numerically higher) But you are rite you must match both front and rear ratios. As far as the carrier bearings go it depends on condition.

 

[CCATLETT1984]

you must change the carrier the split for these axles is 4.10&down or 4.56&up

 

[Angus1]

But he only want to go 3.55 to 3.73 He should be fine. No?

 

[MB4/94]

The carriers have to be changed.

 

[M1075]

It might be easier to swap axles with someone. The higher (numerical) gears are well sought after by the offroad crowd.

 

[JohnFire]

I am beginning to think that too on finding another set of axles from the junkyard and rebuild them.. Lift and bigger tires would make it hard on the back for hauling stuff.

 

[CCATLETT1984]

14bolt rear axles are CHEAP, you'd have to move the spring perches for the m1009 though (not that its hard to do )
look for a dana44 for the front of the 1009, it will bolt in, you can find a 3/t ton model that will have 8lug hubs to match the 14bolt.

or you can get a 1/2ton d44 and look for a 12bolt for the rear.
But, I'd prefer to have the 8lug alxes, esp since the 14bolt full floater wont leave you stranded if you snap an axle shaft.

 

[sweetk30]

1 ton 14ff rear axles split is 4.10-down or 4.56 up. but you DONT NEED A NEW LOCKER the carrier is 2 peice style. you just need a open carrier and swap the locker gut over. the detroit in them replaces the spider unit in a open .

but dana 60 is full carrier swap.

i have not seen 3.42 for 14ff but have heard of them. you might want to do some reserch on just what you can get. but i would do 4" tuff country lift and not rough country . then 35"-37" tires. not to bad for daily driver.

and whole lot cheeper in the end.

 

[CCATLETT1984]

i forgot about the detroit fitting inside the carrier on the 14bolt, that will help with price. 3.73 is probably the perfect gear with nearly stock tires. anything taller (numerically lower) and you will give up pulling power.

 

[cjkeeliii]

This thread is interesting, but I don't understand the 14 bolt, ten bolt, 12 bolt stuff. Can someone explain?

 

[t4billl]

thanks for the info i am getting conflicting info on the detroit locker but I talk to my transmission guy and he set good poss that the carrier would have to be changed , quoted 1600.00 for both axles ouch !!!!

 

[JohnFire]

definately don't want to give up the one ton axles on the M1028. The M1009 is fine as is. For me to raise the ride height on the M1028 when I put a pick up box on it would make it tough for using if I have to actually have to shovel anything into or out of it. Even just lifting something heavy into it could be tought if it is 6-8 inches higher.

 

[CCATLETT1984]

This thread is interesting, but I don't understand the 14 bolt, ten bolt, 12 bolt stuff. Can someone explain?

Those are the different GM axles that where put under the trucks & blazers.
10bolt= used on the 1/2ton trucks and blazers
(it has 10 bolts holding the cover on the differential)
it has ball-joints and is not known for being a strong axle. Used in the front and rear.

12bolt= used on the light 3/4ton trucks
(has 12 bolts holding the cover on)
stronger but used in rear applications only, semi-floating

14bolt= used on heavy 3/4ton & 1ton trucks
(has 14 bolts holding the cover on)
very strong, heavy, full floating (meaning if you snap an axleshaft, the tire stays attached to the truck)

 

[cjkeeliii]

Thanks, that clears up a lot of questions!

 

[m4A1]

If I'm not mistaken the 12-bolt was pre-1980 and the 10-bolt was 1980 on.

 

[AJMBLAZER]

The 12 bolt was used under the rear of half tons prior (officially) to 1978 or so but in reality some still dribbled onto the line into the early 80's as GM found and used up old stock.

3/4 tons only ever got the 14SF or the 14FF.

The M1009 K5 Blazer has 10 bolts front and rear. The M1008 K30 pickup has a Dana 60 front and a 14FF rear.