derekf.com

3 Jan 2020
Differential

I have been dreading this, mainly because I have *no* idea what I'm doing here, and it'll be really easy to screw it up. So, it's time to do something wrong.

Pulling the axle bearings is the first step.

UCAs and LCAs, and shocks, and springs, and brake hoses are the next step, with those disconnected the whole assembly comes out.

Carrier is a 2.73 open.

Lots of room under the car without the axle and gas tank

Driver's side shim is .238

Actually, pass shim is also .238.

With the housing torn down, the grease and dirt can be removed. Scrub, degreaser, soak, rinse, repeat.

Meanwhile, the pinion shim is .026

Cleaned the dirt and oils off, not going to bother trying to polish it up. Good enough for painting.

Primer is Summit epoxy primer.

Paint is a Tractor Supply implement enamel.

Axle stamping is "KD 06 9B". KD indicates - as expected - 2.73 open, in this case.

That might actually be 0619B; Chevellestuff says that'd be made 19 Jun in Buffalo.

Had quite a bit of trouble getting the inner bearing race installed. Here's the stopping point I got to.

Front race went in easily enough

Went ahead and put the bearings on the Truetrac carrier.

Installed the 4.10 ring gear. I was surprised to actually take a part from the pile and attach it to another part. I'd picked up some ARP bolts for the ring gear to use instead of the ones that came in the Summit install kit.

Despite the best efforts of the bearing driver, I was able to get the inner race installed. I actually had better luck using the flat side of the driver rather than the tapered.

The tapered doesn't *really* fit the race.

This is the set I'd used. They're from HF.

I bought the gears in 2005. They sat on a shelf since then, and surface rust has taken hold.

From the Richmond Gear instructions:

"Each set of gears is a matched pair which has been prerun on a gear test machine" .. "since all gear sets have been run-checked, specific settings are supplied with each ring/pinion pair"

"Pinion depth settings are marked on the face of the pinion".

I can't read what it says. It *might* be a serial number of 150 and a depth of 2.792? It looks like something-92, at least.

Alternate pic, seems a little less legible

Also from the instructions:

"Backlash settings are marked on the outside diameter face of the ring gear" as well as serial. This is maybe also serial 150 and backlash of .009?

Richmond support just said that 12 bolt pinion depth is 2.795.

Part number and such.

I tried to use this pinion depth tool. It did not go well.

Step 2 in the Jegs instructions: "Zero the dial indicator using the supplied checking block and appropriate extension.. slide into collet until dial reads zero, then tighten."

The handy chart on the back of the instructions says 12 bolts are 4.670" (this was before I got the response from the Richmond folk), so the 4.3" extension seems appropriate. Figured I'd try it to see what the current shim did.

The 4.3" extension does not bottom out in the checking block so I don't know what this is supposed to do.

Instructions give the setup to be used

This is not what it suggested and I don't understand it.

I don't know what to do with this reading. Probably nothing since it's not zeroed and I don't know how to use it.

Decided the numbers don't matter, it'll be the pattern that really determines how I'm doing.

Having a whiteboard in the garage is helpful for notes.

I can only get about .375 worth of shims in here, rather than the .475 the old carrier had, which concerns me a bit.

Shim kit that came with the rebuild kit had four .100, a couple of .025 and .035 shims, and a bunch of .010.

I was able to try .200/.175 and it's close (.005 is a bit tight) but I think .195/.180 is the right answer, but I don't have enough less-than-.100 shims to do it. Additional shim pack ordered and should arrive tomorrow.

I did try putting the carrier bearings through the press again to see if they could seat any further; they didn't.

While I wait on shims, may as well clean up the underside some. Circled are holes in the weld I did from the top. I'm not going to try to patch the crossmember.

I had planned to run Air-Ride helper bags inside the springs.

Yeah, I don't think that's going to work. The circle-track springs are smaller (4.25" I.D.) than the stock springs (5.75" I.D.). I'll probably look into different bags, I think the helpers will be needed and I don't want to do air shocks.

I've pulled the rest of the parts I'll need for this out - the calipers and brackets, the new yoke, springs, adjustable UCAs. Still need to figure out shocks and brake lines.

I dug through the bucket of parts that came from the initial axle teardown. I'm missing one C-clip. How do you lose a single C-clip?! Ordered that too.

Go back to the previous day (28 Apr 19)

	Pulling the axle bearings is the first step.
UCAs and LCAs, and shocks, and springs, and brake hoses are the next step, with those disconnected the whole assembly comes out. Carrier is a 2.73 open.
	Lots of room under the car without the axle and gas tank
Driver's side shim is .238
	Actually, pass shim is also .238.
With the housing torn down, the grease and dirt can be removed. Scrub, degreaser, soak, rinse, repeat.
	Meanwhile, the pinion shim is .026
Cleaned the dirt and oils off, not going to bother trying to polish it up. Good enough for painting.
	Primer is Summit epoxy primer.
Paint is a Tractor Supply implement enamel.
	Axle stamping is "KD 06 9B". KD indicates - as expected - 2.73 open, in this case. That might actually be 0619B; Chevellestuff says that'd be made 19 Jun in Buffalo.
Had quite a bit of trouble getting the inner bearing race installed. Here's the stopping point I got to.
	Front race went in easily enough
Went ahead and put the bearings on the Truetrac carrier.
	Installed the 4.10 ring gear. I was surprised to actually take a part from the pile and attach it to another part. I'd picked up some ARP bolts for the ring gear to use instead of the ones that came in the Summit install kit.
Despite the best efforts of the bearing driver, I was able to get the inner race installed. I actually had better luck using the flat side of the driver rather than the tapered.
	The tapered doesn't really fit the race.
This is the set I'd used. They're from HF.
	I bought the gears in 2005. They sat on a shelf since then, and surface rust has taken hold. From the Richmond Gear instructions: "Each set of gears is a matched pair which has been prerun on a gear test machine" .. "since all gear sets have been run-checked, specific settings are supplied with each ring/pinion pair" "Pinion depth settings are marked on the face of the pinion". I can't read what it says. It might be a serial number of 150 and a depth of 2.792? It looks like something-92, at least.
Alternate pic, seems a little less legible
	Also from the instructions: "Backlash settings are marked on the outside diameter face of the ring gear" as well as serial. This is maybe also serial 150 and backlash of .009? Richmond support just said that 12 bolt pinion depth is 2.795.
Part number and such.
	I tried to use this pinion depth tool. It did not go well.
Step 2 in the Jegs instructions: "Zero the dial indicator using the supplied checking block and appropriate extension.. slide into collet until dial reads zero, then tighten." The handy chart on the back of the instructions says 12 bolts are 4.670" (this was before I got the response from the Richmond folk), so the 4.3" extension seems appropriate. Figured I'd try it to see what the current shim did. The 4.3" extension does not bottom out in the checking block so I don't know what this is supposed to do.
	Instructions give the setup to be used
This is not what it suggested and I don't understand it.
	I don't know what to do with this reading. Probably nothing since it's not zeroed and I don't know how to use it. Decided the numbers don't matter, it'll be the pattern that really determines how I'm doing.
Having a whiteboard in the garage is helpful for notes. I can only get about .375 worth of shims in here, rather than the .475 the old carrier had, which concerns me a bit. Shim kit that came with the rebuild kit had four .100, a couple of .025 and .035 shims, and a bunch of .010. I was able to try .200/.175 and it's close (.005 is a bit tight) but I think .195/.180 is the right answer, but I don't have enough less-than-.100 shims to do it. Additional shim pack ordered and should arrive tomorrow. I did try putting the carrier bearings through the press again to see if they could seat any further; they didn't.
	While I wait on shims, may as well clean up the underside some. Circled are holes in the weld I did from the top. I'm not going to try to patch the crossmember.
I had planned to run Air-Ride helper bags inside the springs. Yeah, I don't think that's going to work. The circle-track springs are smaller (4.25" I.D.) than the stock springs (5.75" I.D.). I'll probably look into different bags, I think the helpers will be needed and I don't want to do air shocks.