Edgar: The adventures and ramblings of a high mileage 1992 Chevy K1500 RCSB

[nitro_rat]

Good to know! I can imagine that the manual transmission combined with the short wheel base rig that’s light in the back would be a bad idea, especially an aggressive one like a Detroit!

I like the eLocker option, especially since I have no plans for onboard air (for an ARB) other then a small portable pump to air tires back up. I’ve had my eye on lower mileage H2 rear axles (most of them won’t part the axles out). Several salvage yards will sell me the whole rear axle for around $400 with lower miles (Around 90k) and I just looked and they still make the service kits for the Eaton e-locker although they are a bit spendy.

I’ve never set up gears before but want to give it a shot. How hard could it be? ?

I know most folks use new R&Ps, but if the gears are in good shape from the donor axle and the parts are compatible, it would be nice to be able to use the H2’s 4.10s with the e-locker... With a GT5 4.10 front diff from the Pick-N-Pull I’d be in business.

I figure that will be a project for next winter though, but it would be good to have my ducks in a row ?

That axle is super easy. You just need a dial indicator to measure backlash, Beam type inch pound torque wrench, and a 0-1" micrometer or accurate vernier caliper.

The AAM axle housings are machined accurately enough that as long as you are using a factory gear set, the pinion shim requred is alwas the same for a given HOUSING. That means whatever shim is in your factory housing will work on whatever other factory pinion you put in that housing!

I would recommend a crush sleeve eliminator kit that uses shims. Just measure the thickness of your crush sleeve and start with .002" more shims. Work down until you get the specified turning torque.

Backlash is set with the big nuts on either side of the carrier. They make a tool for that but you can tap it around with a punch. Set backlash to whatever you measured befpre disassembly.

Easy...

 

[TwinDuro]

That axle is super easy. You just need a dial indicator to measure backlash, Beam type inch pound torque wrench, and a 0-1" micrometer or accurate vernier caliper.

The AAM axle housings are machined accurately enough that as long as you are using a factory gear set, the pinion shim requred is alwas the same for a given HOUSING. That means whatever shim is in your factory housing will work on whatever other factory pinion you put in that housing!

I would recommend a crush sleeve eliminator kit that uses shims. Just measure the thickness of your crush sleeve and start with .002" more shims. Work down until you get the specified turning torque.

Backlash is set with the big nuts on either side of the carrier. They make a tool for that but you can tap it around with a punch. Set backlash to whatever you measured before disassembly.

Easy...

Thanks again for the info @nitro_rat, that is all exactly what I needed! I'll definitely give it a go. I was wondering about the crush sleeve... it sounds like a crush-sleeve eliminator kit would be good for a first timer as if I don't get it quite right the first time, it sounds like I won't have to get a new crush sleeve, just reassembly.

There's a complete H2 rear axle available with 4.10s and the Eaton e-locker for a very reasonable price (under $500) with 76K miles on it. It's mighty tempting. Even though all I'd be using is the R&P, e-locker and e-locker related hardware along with a few other odds and ends, I'm sure someone nearby could make use of the rest of the housing with the rear brake setup. The 2-piston calipers and parking-brake in-hat rotors on those H2 rear brakes are huge or at least they seem that way.

I'm just about to pull the trigger on a set of new 4/1 2,025lb rated rear leafs as well. The truck currently has sacked-out original 3/1 1,425lb rated leafs in it. I've got a set of KYB Monomax rear shocks ready to go as well.

 

[nitro_rat]

Thanks again for the info @nitro_rat, that is all exactly what I needed! I'll definitely give it a go. I was wondering about the crush sleeve... it sounds like a crush-sleeve eliminator kit would be good for a first timer as if I don't get it quite right the first time, it sounds like I won't have to get a new crush sleeve, just reassembly.

There's a complete H2 rear axle available with 4.10s and the Eaton e-locker for a very reasonable price (under $500) with 76K miles on it. It's mighty tempting. Even though all I'd be using is the R&P, e-locker and e-locker related hardware along with a few other odds and ends, I'm sure someone nearby could make use of the rest of the housing with the rear brake setup. The 2-piston calipers and parking-brake in-hat rotors on those H2 rear brakes are huge or at least they seem that way.

I'm just about to pull the trigger on a set of new 4/1 2,025lb rated rear leafs as well. The truck currently has sacked-out original 3/1 1,425lb rated leafs in it. I've got a set of KYB Monomax rear shocks ready to go as well.

Yes, $500 for a locker, and ring/pinion is a good deal! You can probably offload what you don't use to offset that cost even further.

You may have to crank the torsion bars to level it off if you get heavier rear springs. I bought a shot bed single cab that had heavy springs in it once and it was like 6" up in the back. I ditched them for the regular setup. YMMV on that one...

 

[TwinDuro]

Small update, got the rear leaves ordered (decided to go with the F44-spec 4/1 leaves, can always pull a leaf down the road if they’re too stiff ?) and a WFO concepts U-bolt flip kit which has beefy 5/8” U-bolts and 3/8” thick spring plates.





I was originally going to go with a Off-road Designs U-bolt flip kit but the U-bolts were waaaay too long for my needs (the WFOs are 9” long, the ORDs are 11” and I need 8”). Sure, the extra thread could be hacked off, but easier just to buy the right length ?

Also on the way soon are a set of new Spicer SPL grease-able u-joints for the driveshaft with a strap kit for the pinion yoke, a new output shaft seal for the T-case and some other odds and ends of install the new rear axle.

I’m gonna wait on doing an e-locker/4:10 gear install for the moment. As badly as I want to, the funds could be better used for some more critical parts for the drivetrain/brakes at this time... I’m defiantly doing this as soon as it’s feasible though!

 

[TwinDuro]

Here’s also a photo of the worst U-joint I’ve ever pulled out of something, a Spicer 1330 out of the front driveshaft of my buddy’s 2006 Nissan Titan with 75k miles on it. It was more clacky then a tap dancer and more wallered then an out of control post-hole auger. All of the needle bearings went off to the land of wind and ghosts and never returned.



We picked up some new greasable U-joints at Napa, gave ‘er a quick coat of paint and pressed it all back together and she’s been working great ever since. The front driveshaft on Nissan Titans spins all of the time wether the transfer case is engaged or not I learned, unlike the GMT400.



In the coming weeks I’ll be doing the same to Edger’s drive shafts...

 

[nitro_rat]

I would be surprised if the driveshaft isn't always spinning in a GMT400. There are no locking hubs. Disconnecting the long side shaft will slow things down and alleviate binding but the single engaged axle shaft will drive the drive shaft.

A friend of mine has a Suburban with a Dana 60 that's lifted enough to clearly see the front driveshaft when he's going down the road. Even with both hubs unlocked, there is enough friction that the driveshaft can be observed turning slowly when he's going down the road at highway speeds.

 

[TwinDuro]

I would be surprised if the driveshaft isn't always spinning in a GMT400. There are no locking hubs. Disconnecting the long side shaft will slow things down and alleviate binding but the single engaged axle shaft will drive the drive shaft.

A friend of mine has a Suburban with a Dana 60 that's lifted enough to clearly see the front driveshaft when he's going down the road. Even with both hubs unlocked, there is enough friction that the driveshaft can be observed turning slowly when he's going down the road at highway speeds.

That makes total sense @nitro_rat. That assuming is getting me into trouble again! The new rear springs are supposed to come today, looking forward to checking those out. Also waiting on a box with all the little stuff for the rest of the rear axle install. Decided to have the drums turned at the machine shop since they were a bit rough from sitting and am going to install all new brakes parts (including shoes and all the hardware and brake adjusters) while it's apart. Figured now was as good of time as any.

On to the front differential... I know that one of the beefs (among many) with the GM 8.25 and 9.25 IFS front diffs is having the thermal actuated front axle disconnect failing or not working when you need it to (cold weather, etc). Mine's working fine, but I'd like to bomb-proof it a little bit. Someone told me a newer, motorized upgrade was available and then there's always the cable actuated 4x4 Posi-Lok kit. Any thoughts from folks familiar with GMT400s? I like the idea of the Posi-Lok, because being able to shift the T-case into low range with the front axle disconnected for 2WD-Low would be handy when backing trailers (I help friends out with their horse trailers pretty regularly, which always seems to involve backing them into weird places), but realize that I'd have to keep that cable lubed up to prevent it from giving me trouble as well.

I'm looking forward to getting this chunk of the project underway!

 

[nitro_rat]

Posi lock makes a full time engagement slug. That's the one I like. The only time I like a shiftable posi lock is on a dodge with a front locker.

 

[chilliwak]

Small update, got the rear leaves ordered (decided to go with the F44-spec 4/1 leaves, can always pull a leaf down the road if they’re too stiff ?) and a WFO concepts U-bolt flip kit which has beefy 5/8” U-bolts and 3/8” thick spring plates.

View attachment 580009

View attachment 580010

I was originally going to go with a Off-road Designs U-bolt flip kit but the U-bolts were waaaay too long for my needs (the WFOs are 9” long, the ORDs are 11” and I need 8”). Sure, the extra thread could be hacked off, but easier just to buy the right length ?

Also on the way soon are a set of new Spicer SPL grease-able u-joints for the driveshaft with a strap kit for the pinion yoke, a new output shaft seal for the T-case and some other odds and ends of install the new rear axle.

I’m gonna wait on doing an e-locker/4:10 gear install for the moment. As badly as I want to, the funds could be better used for some more critical parts for the drivetrain/brakes at this time... I’m defiantly doing this as soon as it’s feasible though!

Nice looking springs there Mr Duro. Cheers, Chilli.. ?

 

[vargsmetal]

Nice truck! Super lucky to find a RCSB 1500 with a factory NV4500.

I did the motor actuator upgrade on the front diff to my 1990 and it seemed great until I submerged it. Whether I use factory or aftermarket replacement actuators they always fail after a dunking. The last one I put in has lasted the longest but, I've gone through 4 in the last year. When they do fail to actuate you can make a spacer out of quarters or washers to get 4wd back...

Just get the cable setup, or the slug to leave it engaged all the time. If you don't do a ton of highway miles you won't notice the difference in fuel economy using the slug.

Sent from my SM-G965U using Tapatalk

 

[vargsmetal]

Also, you'll like the 4+1 springs. They are just right to me. You can haul some serious weight without much sag, but they're still soft enough to ride ok unloaded and flex out offroad.

Sent from my SM-G965U using Tapatalk

 

[tip]

What a cool little rig! Love the simplicity of the GMT400.

Looking forward to following this one.

 

[TwinDuro]

Nice truck! Super lucky to find a RCSB 1500 with a factory NV4500.

I did the motor actuator upgrade on the front diff to my 1990 and it seemed great until I submerged it. Whether I use factory or aftermarket replacement actuators they always fail after a dunking. The last one I put in has lasted the longest but, I've gone through 4 in the last year. When they do fail to actuate you can make a spacer out of quarters or washers to get 4wd back...

Just get the cable setup, or the slug to leave it engaged all the time. If you don't do a ton of highway miles you won't notice the difference in fuel economy using the slug.
Sent from my SM-G965U using Tapatalk

Hey @vargsmetal! Thanks! I appreciate your kind words it and I did get super lucky on finding this particular truck. There's a bit of work ahead, but it's all worth it to me and I'm looking forward to some adventures this summer!

Also, I've enjoyed the heck out of your thread on your '90 K1500 and have gained a lot of knowledge and inspiration following it. Considering how relatively stock your '90 is suspension-wise, it's awesome to see where you guys have taken it on all of your adventures (great photos by the way!) and I love the photos of it flexed out on the trails! I'm looking forward to seeing your new build on your '91 RCSB progress and am glad to hear your '90 is sticking around as a daily/backup. I can relate to the newer 4Runner as well, great rigs! A friend had a 2017 TRD Off Road version that I borrowed on several occasions and it was always hard to hand back the keys... ?

Thanks for the advice on the front axle actuator (and from @nitro_rat as well). It's good to know what the trail-fix for the actuator is and I'll definitely ditch it in favor of the slug or the cable, just need to make up my mind. Also, I never noticed in the thread on your '90, but did it come with a G80 or did you put a locker in the rear axle or is it still an open diff? Just curious.

Also, you'll like the 4+1 springs. They are just right to me. You can haul some serious weight without much sag, but they're still soft enough to ride ok unloaded and flex out offroad.

Sent from my SM-G965U using Tapatalk

Great to know on the rear springs am glad I went that route. I often haul pallets of bagged concrete and lots of sheets of plywood and drywall, so I didn't want to go too light, but also didn't want it riding like a buckboard.

 

[TwinDuro]

What a cool little rig! Love the simplicity of the GMT400.

Looking forward to following this one.

Thanks Tip! Stay tuned, more parts are on the way!

 

[TwinDuro]

Todays latest braking news, the rear drums from the 9.5 SF were a bit rough, so I dropped them off at the local machine shop. Great service and it picked them up and oh la la! A quick cleanup and coat of paint and they’ll be good to go.