kapnklug
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Ok so I realize most of you running a GM 14-bolt rear axle already HAVE a Detroit Locker, but when I swapped civilian 8-lug axles (with 4.10 gears) into my M1009, I was stuck with an open differential in the rear. Fortunately the Detroit Locker can be installed inside the open carrier of the GM 14-bolt without changing the carrier (and having to reset the backlash). Total installation was about 3hrs, but coulda been quicker if I'd had this post to refer to.
Basic procedure for removing the differential is in TM -34 pg. 646, but you can skip alot of steps. First, you don't need to remove the wheels, or even jack up the truck if you have sufficiently large tires. Remove the 8 bolts holding the axleshafts to the hubs, put a rag under the hubs to catch the little bit of oil that will come out, then pull the shafts out 6in.
I used a sharp chisel to scribe the bearing caps for left and right, at the bottom, before removing them. Then use a punch to mark the side-adjusters before backing them off 1.5 turns each side, so you can screw them back later without resetting the backlash (very time consuming). The carrier may now fall right out; careful -- it is HEAVY! Approx 50lbs. The races will fall off the side bearings at this point, don't mix them up (left/right).
Only real problem I had was securing the carrier in a vise tight enough to remove/install the ring gear bolts at 120 ft/lbs. After a bit of wrestling with it, I placed one jaw of the vice on a single ring gear bolt head, and the other jaw against a scrap of 1/2" plywood that protects the ring gear teeth (see pics). Then you can really crank the vice down enough to keep the whole carrier from rotating out of the vice and breaking your foot. Scribe the two halves of the carrier with a chisel before removing the bolts so they can be reassembled in the same orientation.
After separating the case, remove the trunnion, spider gears and side gears. These will not be going back in. Be sure to remove the thrust washers under the side gears, that will try to stick in the case. My unit had several burrs on the case halves that needed to be removed with a flat file, mostly around the outer diameter and some on the inside edges of the bores that hold the trunnion. The new Locker (shown in my hand in the pic) will drop right in. This one was $470 (delivered) on Flea-Bay. It is held together with a long bolt to compress the internal springs; bolt the carrier halves back together (120 ft-lbs) BEFORE removing the bolt or pieces will fly everywhere.
This is a good time to clean out the housing, including the case magnet. Make sure there is no debris on the flats where the bearing caps will go. Put the side-bearing races back on the bearings with some bearing grease to hold them in place, then push the whole thing back into the housing. A helper would have been great; did I mention it's heavy? Put the bearing caps back according to your scribe marks but don't torque the bolts down yet. Tighten the side adjusters (down on the drivers side, up on the pass. side) until the punch marks you made are front and center. Make sure the carrier rotates easily, with roughly the same backlash it had before. Then torque the bearing cap bolts to 135ft-lbs and install the adjuster locks. Rest of assembly is straight-forward; I needed to put the truck in neutral to get the axleshafts bolted to the hubs, since I didn't jack up the wheels.
As you might expect, the driving difference is night and day; 2WD is the new 4WD!
The pics are a little out of order:
1. Detroit locker installed in drivers case half
2. Pass. case half, with parts that will not be re-used
3. What you get for $470. Don't remove that long bolt yet!
4. Driver's case half with stock side gear still in bore
5. How to hold the thing in a vise without damaging it or you
6. Just pull the axles out a little
7. What it looks like inside there
8. I punched holes in cardboard, to keep the parts from getting mixed up left/right/up/down
Basic procedure for removing the differential is in TM -34 pg. 646, but you can skip alot of steps. First, you don't need to remove the wheels, or even jack up the truck if you have sufficiently large tires. Remove the 8 bolts holding the axleshafts to the hubs, put a rag under the hubs to catch the little bit of oil that will come out, then pull the shafts out 6in.
I used a sharp chisel to scribe the bearing caps for left and right, at the bottom, before removing them. Then use a punch to mark the side-adjusters before backing them off 1.5 turns each side, so you can screw them back later without resetting the backlash (very time consuming). The carrier may now fall right out; careful -- it is HEAVY! Approx 50lbs. The races will fall off the side bearings at this point, don't mix them up (left/right).
Only real problem I had was securing the carrier in a vise tight enough to remove/install the ring gear bolts at 120 ft/lbs. After a bit of wrestling with it, I placed one jaw of the vice on a single ring gear bolt head, and the other jaw against a scrap of 1/2" plywood that protects the ring gear teeth (see pics). Then you can really crank the vice down enough to keep the whole carrier from rotating out of the vice and breaking your foot. Scribe the two halves of the carrier with a chisel before removing the bolts so they can be reassembled in the same orientation.
After separating the case, remove the trunnion, spider gears and side gears. These will not be going back in. Be sure to remove the thrust washers under the side gears, that will try to stick in the case. My unit had several burrs on the case halves that needed to be removed with a flat file, mostly around the outer diameter and some on the inside edges of the bores that hold the trunnion. The new Locker (shown in my hand in the pic) will drop right in. This one was $470 (delivered) on Flea-Bay. It is held together with a long bolt to compress the internal springs; bolt the carrier halves back together (120 ft-lbs) BEFORE removing the bolt or pieces will fly everywhere.
This is a good time to clean out the housing, including the case magnet. Make sure there is no debris on the flats where the bearing caps will go. Put the side-bearing races back on the bearings with some bearing grease to hold them in place, then push the whole thing back into the housing. A helper would have been great; did I mention it's heavy? Put the bearing caps back according to your scribe marks but don't torque the bolts down yet. Tighten the side adjusters (down on the drivers side, up on the pass. side) until the punch marks you made are front and center. Make sure the carrier rotates easily, with roughly the same backlash it had before. Then torque the bearing cap bolts to 135ft-lbs and install the adjuster locks. Rest of assembly is straight-forward; I needed to put the truck in neutral to get the axleshafts bolted to the hubs, since I didn't jack up the wheels.
As you might expect, the driving difference is night and day; 2WD is the new 4WD!
The pics are a little out of order:
1. Detroit locker installed in drivers case half
2. Pass. case half, with parts that will not be re-used
3. What you get for $470. Don't remove that long bolt yet!
4. Driver's case half with stock side gear still in bore
5. How to hold the thing in a vise without damaging it or you
6. Just pull the axles out a little
7. What it looks like inside there
8. I punched holes in cardboard, to keep the parts from getting mixed up left/right/up/down
