Will's Bug Out Rig: Duramax Van

[The Dark Side of Will]

I do. I snagged a 2011+ 9.25" 3.73 front a few months back. I haven't posted pics of it because I haven't done anything with it yet.

FYI, although I'm sure you already know this, later model(07+IIRC) GM 8 lug parts are 8x180mm instead of 8x6.5" I'm not sure what hub/axle compatibility could overcome that though.

Right. Per RockAuto that was '11 for the pickups. That coincided with a big upgrade in front drive hardware. The 8x180 hubs and corresponding outer CVs have 36 splines, while the 8x6.5 & CVs have 33 splines (most likely the same 33 splines as the large FWD cars and C7 Corvettes). The older inner CVs mount to the diff output flanges with 6 bolts, while the '11+ inners mount with 8. I have not yet done enough research to figure out if there's an easy way through that, like if the old outers spline onto the new bars or if the new inners spline onto the old bars. Worst case, I get DriveShaftShop or similar to cut me custom bars to plug into the new inners and the old outers.
The inner CV flanges sit just inside the frame rails, so I'm not sure I have the space for an adapter plate.

[The Dark Side of Will]

Looking through CV axle stuff:

2011+ CV axle
https://www.rockauto.com/en/moreinfo.ph ... 2&jsn=1617

2010- CV axle
https://www.rockauto.com/en/moreinfo.ph ... cc=1445457

Rock does not have listings of what splines the axle bars use at inner and outer ends.

However, I also noticed that Rock has listings for the diff output flanges

2011+ Left
https://www.rockauto.com/en/moreinfo.ph ... cc=1446602



Length: 6.1
Spline: 33
Shaft Diameter: 1.59

2010- Left
https://www.rockauto.com/en/moreinfo.ph ... 7&jsn=1640



Length: 5.84
Spline: 33
Shaft Diameter: 1.62

2011+ Right Inner
https://www.rockauto.com/en/moreinfo.ph ... cc=1446602



Length: 6.22
Spline: 33
Shaft Diameter: 1.5

2010- Right Inner
https://www.rockauto.com/en/moreinfo.ph ... cc=1445457



Length: 6.22
Spline: 33
Shaft Diameter: 1.5

2011+ Right Outer
https://www.rockauto.com/en/moreinfo.ph ... cc=1446602



Length: 15.07
Spline: 33
Shaft Diameter: 1.62

2010- Right Outer
https://www.rockauto.com/en/moreinfo.ph ... cc=1445457



Length: 14.89
Spline: 33
Shaft Diameter: 1.62

Being able to swap the older style output flanges into the newer style diff would be very handy. I guess I just need to pull the flanges from my current diff and make sure I correlate the shaft diameter to the correct place on the shaft. I was thinking that the 1.59 to 1.62 changes are most likely to be at the seal journal, as the common 33 spline has a 1.5" diameter. The length differences are potentially confounding, but if the differences are outside the housing, Then it should still go together.

I also have some insight on the engine mounting, and have received the bolt in crossmember from an AWD 1500, but still need to grab photos.

[The Dark Side of Will]

In light of the above info, I snagged a 2010- front diff from a yard local enough that their delivery service could drop it off at the CarQuest in my dad's town. We know the proprietor, so we use that shop when a delivery driver needs to leave something at a business.

The diff has a broken mount and was listed for parts, so it was cheap. Since I don't need it as a diff, that's fine with me. I'll check whether the output flanges can swap over or not.
Also, I do need to get one of each style of CV axle to see if the joints can be swapped, as that would probably be easiest.

[ericjon262]

I suspect they don't list the bar splines, because aftermarket suppliers probably don't build them with the factory spline count, similar to how they do with Fiero axles. To them, the only important part is that it fits the differential, and the hub.

[The Dark Side of Will]

I suspect they don't list the bar splines, because aftermarket suppliers probably don't build them with the factory spline count, similar to how they do with Fiero axles. To them, the only important part is that it fits the differential, and the hub.

Right, nothing requires the Chinesium versions to have the same internal splines as the OE versions.
Older diff was delivered, but I was at drill last weekend so I haven't seen it yet. Probably the next step is to snag used OE axles to check CV joint compatibility.

I want to get The Mule assembled before snagging a development frame.

//

Since the Diesel/Big Block van body moves the center of the engine bay opening--and thus the powertrain--2" to the right compared to the small block/V6/LS body, I conjectured that the left engine mount bracket that bolts to the frame would be shorter for the LS applications, which would help me raise the baseplate for the engine mount bracket, to make clearance for the diff. I snagged one... it's not shorter. Just call me Edison.

[The Dark Side of Will]

Found out why my high blower speed stopped working. I reseated the connector and it started working again... no problem, right?



Going to snag a connector body and some pins to replace this. I'm pretty sure I correctly seated the connector when I replaced the blower resistor module (the clean part), so I'm going to chalk this one up to old/worn pins that were designed a smidge too small for blower current to begin with.

Also replaced the coolant surge tank with a new one. The coolant level sensor is integral with the tank, so when it goes bad, you need to replace the entire tank to turn off the low coolant light. Coincidentally, it's still weeping coolant from the radiator end tank, so I just waited until the level of the coolant dropped *just* below the bottom of the old tank, then made the switch. I didn't even have to catch any coolant.

[ericjon262]

Found out why my high blower speed stopped working. I reseated the connector and it started working again... no problem, right?



Going to snag a connector body and some pins to replace this. I'm pretty sure I correctly seated the connector when I replaced the blower resistor module (the clean part), so I'm going to chalk this one up to old/worn pins that were designed a smidge too small for blower current to begin with.

Also replaced the coolant surge tank with a new one. The coolant level sensor is integral with the tank, so when it goes bad, you need to replace the entire tank to turn off the low coolant light. Coincidentally, it's still weeping coolant from the radiator end tank, so I just waited until the level of the coolant dropped *just* below the bottom of the old tank, then made the switch. I didn't even have to catch any coolant.

Those "blower resistors" fail all the time on GMT 800 trucks, I need to replace the one in my 2500. There was actually a TSB or recall on them at one point IIRC. If the vehicle was less than 10 years old, the dealer was supposed to replace them free, when mine went the first time, it was about 10 years 2 months old...

[pmbrunelle]

Temperature is the limiting factor... and when things go south, a positive feedback loop apparently happens:
Increasing temp causing
Increased contact resistance (conductor tempco) causing
Increased Joule heating, then back to start

If you buy connectors from a place like TE Connectivity (in automotive quantities), you don't have to rely on their generic current ratings. They will do thermal simulations for you, and in this case, considering heat conducted from the resistor would be pretty important.

One thing you'll notice in the catalogs is that with the same terminal, you have more current capacity from a larger-gauge wire. This is because of the heatsinking from the bigger wire.

If you can crimp bigger-gauge wires into your terminals (versus stock), you may increase the reliability of your setup... just make the splice with the van's wiring some distance away.

[The Dark Side of Will]

Temperature is the limiting factor... and when things go south, a positive feedback loop apparently happens:
Increasing temp causing
Increased contact resistance (conductor tempco) causing
Increased Joule heating, then back to start

If you buy connectors from a place like TE Connectivity (in automotive quantities), you don't have to rely on their generic current ratings. They will do thermal simulations for you, and in this case, considering heat conducted from the resistor would be pretty important.

One thing you'll notice in the catalogs is that with the same terminal, you have more current capacity from a larger-gauge wire. This is because of the heatsinking from the bigger wire.

If you can crimp bigger-gauge wires into your terminals (versus stock), you may increase the reliability of your setup... just make the splice with the van's wiring some distance away.

Same thing happens with aluminum wiring in some older houses and buildings... High demand warms up the screw terminal connection of the wire to the outlet; the aluminum wire creeps, relaxing contact force & increasing contact resistance; the contact warms further, allowing the aluminum to relax more... Eventually either the circuit opens or a fire starts.

The dealership has a pigtail for $73... I'm going to see if I can find a connector kit. The two torched contacts are the high speed supply wire and the main ground wire. These are listed as 5mm^2... this doesn't translate directly to a AWG, but falls in between 10ga & 12ga, so there's not any room to go bigger on those wires. The lightly charred one on the end is the 2nd from highest speed. It's 0.8mm^2, which is 18ga, so there's room for increase there.

[The Dark Side of Will]

Wow, Ballenger Motorsports didn't have the connector body, but they steered me onto an eBay auction for it.

https://www.ebay.com/itm/263533462252

PN 12160746
I just bought it from the eBay sale. I'll snag the terminals, seals and CPA from Ballenger and get that schtuff fixed.

EDIT: Now that I know the PN to look for, I see that the GMUpfitter electrical manual lists it, but is not very specific about what it is... and their diagram is much more difficult to interpret than the FSM diagram.

[ericjon262]

the trucks have the connector inside, and not weather sealed. I need to see about finding a replacement connector too. I don't want to replace the whole pigtail

[The Dark Side of Will]

the trucks have the connector inside, and not weather sealed. I need to see about finding a replacement connector too. I don't want to replace the whole pigtail

There's at least one more body on eBay right now.

Edit: Or did you mean the GMT800's use a different connector?

[ericjon262]

the trucks have the connector inside, and not weather sealed. I need to see about finding a replacement connector too. I don't want to replace the whole pigtail

There's at least one more body on eBay right now.

Edit: Or did you mean the GMT800's use a different connector?

yeah, GMT 800's don't have a weather tight connector, the resistor is in the cab of the truck. I replaced mine earlier today, it's nice to have working AC again.

[The Dark Side of Will]

The right rear brakes started grinding last week, so I went ahead and ordered pads & rotors for all four corners. I also ordered replacement hoses, but I'll let the shop deal with those.

I did the rears first. Both sides were stuck pretty firmly, but we were able to put together a puller setup that popped them off (literally!)



There was so much load on the puller that this one jumped a foot and a half when the rotor broke loose from the hub.



THIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIICCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC



The residue is penetrating oil

Prior (original?) front brakes



The new hawttness: The 3500 and 4500 rotors had identical dimensions with a little thicker sides and a little less air-gap in between the two flanges on the 4500 units. The 4500 units are also 3lbs heavier. I bought them.



1 7/16" thick:



Due to RockAuto stock, the front pads are one level more premium than the rear pads. They are Akebonos:



They are both ceramic; the front pads have the coveted GG coefficient of friction, while the rears have FF.

I. Like. Big. BRAKES and I can not lie:

[ericjon262]

I really need to give the brakes on my 2500 some love, I think the hardest part will be finding the time to do it. interesting note on the front break rotors, I'll have to keep that in mind when I need new rotors.

[The Dark Side of Will]

I really need to give the brakes on my 2500 some love, I think the hardest part will be finding the time to do it. interesting note on the front break rotors, I'll have to keep that in mind when I need new rotors.

You were probably a victim of autocorrect, but I still find this funny...

[ericjon262]

I really need to give the brakes on my 2500 some love, I think the hardest part will be finding the time to do it. interesting note on the front break rotors, I'll have to keep that in mind when I need new rotors.

You were probably a victim of autocorrect, but I still find this funny...

Ugh. You have no idea how much this disappoints me... I hate it so much when people mix up break and brake, and now, either I have done it, or F$&+(#G autocorrect got me.

[pmbrunelle]

By any chance, are those two extra holes (not the ones for the lug studs) in the rotor hat threaded?

Couldn't you screw in a pair of bolts to push the rotor off the hub face, without storing a bunch of elastic energy and having the rotor go flying?

If the holes on the new rotors aren't already threaded, it might be a good idea to do so now.

I once did a brake job on a friend's car, and I used those holes to remove the rotor, and it worked well.

[The Dark Side of Will]

Well you know what... Since I've never had this much trouble getting rotors off before, I didn't think about that

I've seen the German method of retaining rotors with a flat head screw and associated those holes with that without thinking about the fact that the holes are completely wrong for that application

EDIT: In looking at my photos more closely, I see that the old front rotors had those holes but the old rear rotors did not... so knowing was not half the battle and would not have helped in getting the rear rotors off, which were the difficult ones.

[The Dark Side of Will]

Ugh. You have no idea how much this disappoints me... I hate it so much when people mix up break and brake, and now, either I have done it, or F$&+(#G autocorrect got me.

Lol! It's because you normally don't mess that up that it got my attention... and I also just found that fire meme and had to drop it someplace!

Maybe I'll go start a topic on Old Europe...