Bajablazer85: 1985 Chevrolet S10 Blazer Build

[Bajablazer85]

Whats up ExPo! I've been a long time lurker of this site. I adore the builds and adventure reports I've seen here, and I wanted to give back with my own build.

I'm a Californian, born and raised. I grew up on a healthy amount of road tripping and adventuring. Parents had a 1987 Chevrolet Astro which towed a pop-up tent trailer. We took that rig from Mexico to Oregon, California to Colorado. I'll be honest, it was all mere "car camping" compared to what some of you do! But it's proving to be a good baseline for me to develop a taste for something more...

Recently, I've been casually exploring the Eastern Sierran Nevadas in my 2002 Subaru Forester. Mono Lake/Hwy 395/Mammoth Lakes are my happy place. However, this vehicle is not much more than a commuter car for me. While it is capable for car, it lacks what I need in utility and capability. Still, a great car in its own right!

Queue: Bajablazer85. This project has been a long time coming. This first post will be an abridged history of this truck with me.

I inherited it from my passing grandfather in about 2007; it was my first car.

I drove the truck through high school and as much of college as I could, slowly making cheap and simple mods to it over time. I'd post about everything I did to it over those years, but as you will see, those mods will become dwarfed and obsolete over the course of this project.

Focusing on college, and keeping this Blazer running became too much of a challenge. I put it into storage with the intent to fully restore and engine swap it when I graduated and got a career started.

Welp, I've graduated and I have an income. Given the history of the truck in my family, I feel as though I need to give it what it deserves. My initial goal is to make it mechanically reliable and capable. Dumping the original 2.8L V6 with the awful rochester feedback carbureted system is a MUST if I want any sort of dependability. Chassis, suspension, steering, braking mods will be basic at first until I can feel out the weak links in the system.

Once I'm comfortable with the dependability of the vehicle, I will begin outfitting it for short expeditions. 2-3 days capability. I have yet to decide if a lightweight teardrop trailer, a RTT, or simply carrying a tent is the way I want to go.

 

[Bajablazer85]

Post #2, revival and teardown

December 2015, yanked it out of storage. What it looked like.

Motor ran and drove as good as she did when I parked her. However, the 5 hour journey from my parent's place where it was kept to the bay area would be too risky. I tried to get her past smog, just to see what would happen. Not gonna fly!

Finally in her new home. Started tearing into the project less than a week of having it back. Couldn't help myself!

Engine swap is the first order of business. From the get-go, I never wanted this to be an engine-swap, hot-rod project (if I did, I'd be doing an LS V8, which you'll see I am NOT doing). However, the 2.8L with the feedback carb is so awful, I have no choice. Engine, transmission, and transfer case were removed as a single unit, as the compact design of the S10 platform would require splitting the body from the frame to remove the engine separately from the transmission. Additionally, I will be performing this restoration in a single car garage. Every step I take on this has to be of the upmost production rate.

All suspension and steering components were stripped to make a bare frame. Despite how nice the truck was on the exterior and interior, mechanically everything was beat to hell and back. Thank young adult male driving habits for that.

The frame was cleaned with heavy degreaser followed by dish soap and finished with a non-residual parts cleaner. Then primer'd and painted black.

 

[Bajablazer85]

Post #3 - The Organ Donor

The 3.4l V6, and 4L60E transmission from a 1994 Chevrolet Camaro is the engine swap of choice for my Blazer. A lot of hot-rodders or 4wheelers might have gone for a small block Chevy swap, as that is a very common swap in the S10's. I did not find that to be within the character of my truck, and doing a swap like that would risk fuel economy and reliability of driveline components, falling victim to the larger powerplant. Additionally, the 3.4L V6 is the same platform as the Blazer's 2.8L V6: a GM 60 degree V6. Imagine this engine being the same as original, except more displacement and with a more reliable and efficient fuel injection system. This makes everything bolt-on, with little custom work to be done.

Lastly, California smog laws stipulating that any motor swap must utilize the donor car's engine and transmission as a unit. This would not prove to be an issue with my 4WD system, because the Camaro's 4L60E is also the same platform as the Blazer's original 700R4 - just computer controlled. The transfer case simply bolts on the back once the tailshaft housing is removed and the 4x4 output shaft is swapped. The Blazer's torque converter would be used in the new 4L60E.

Dropped the engine out the bottom with the K-member.....

Along with the engine and transmission, the entire electrical system was saved. I plan to run a standalone EFI harness for the motor/trans in the Blazer, separate from the chassis harness.

You bet I'm saving the Corvette replica Grant steering wheel!

The fuel tank and entire fuel/evap system was saved too. I will be using all of these parts to adhere to California smog laws.

 

[Bajablazer85]

Post #4 - Transmission and front driveline

Back to the Blazer.

As I touched on above, California emissions regulations stipulate that I must use the same transmission that came from the donor car in a motor swap. Fortunately, using the 4L60E from the Camaro with the Blazer's transfer case isn't going to be a problem. The 4L60E is physically the same as the 700R4, just computer controlled. However, I will have to do the following to the 4L60E:

1. Remove 4L60E tailshaft housing to make way for transfer case.
2. Extract the 4x4 output shaft from the 700R4 and install it into the 4L60E.
3. Install a 40 tooth reluctor ring and vehicle speed sensor in the 4L60E output case. This will send a speed signal to the PCM to control shifting.

Time for my first transmission rebuild. I started out by tearing apart the old 700R4 to recover the 4x4 output shaft. I took little regard to keeping it nice, as all I needed from it was the 4x4 output shaft. It was a good first step, as I could familiarize myself with the internals of an automatic transmission before I rebuild the ACTUAL one I'd be using.

The 4x4 output shaft was recovered, and I found that the planetary gears had to be taken from the 700R4 so that the 4x4 output shaft would work. You may be able to tell in this photo that the length of the 4x4 splined output shaft made the c-clip fall into a different place on the planetary gear spline. This was confirmed to be the correct solution by ensuring the output shaft end-play was in spec after reassembly.

Changed to a clean tarp frequently, and began carefully disassembling the 4L60E. When rebuilding transmissions, it is IMPERATIVE that you work on a clean and sanitary surface. Any abnormalities that make their way into the transmission valving will spell disaster.

All cleaned and buttoned up. At this point, I installed the Blazer's torque converter. This torque converter's stall speed is more tuned for the gearing and tire size of a truck rather than a car, unlike the Camaro's torque converter. I had no issues with it in the Blazer, so that's dollars saved.

Lastly, I installed the electronic vehicle speed sensor and 40 tooth reluctor ring into the 4L60E output case. This is required for the 3.4L PCM to get a speed input (to control the transmission gear shift). This sensor is separate from the original Blazer cable driven sensor to the speedometer, so I didn't have to be mess with that! For more information on VSS, see chapter 12 of Jags That Run's V8 conversion manual...
http://www.jagsthatrun.com/V8-chapters/V8-tpi-Speed-Sensors.pdf

For the transfer case and front axle, I already knew there was little to no issues with them operating in the Blazer. I disassembled the transfer case and front axle, but only to inspect and re-seal.

Gotta include the cleaning picture. Blasting the old caked grease off was sooooo nice.

Mock up assembly. Transfer case shifts good.

 

[4x4x4doors]

I'm subscribed. Have always had a place in my heart for the S10 and Blazers.

 

[geckoadventure]

Ok I subscribed also

 

[jpat30]

Man does this bring back a flood of good memories; I had a 1984 GMC S15 as my first vehicle. I too had the 2.8 liter (turd) with crappy Rochester carb. On cold mornings I would have to stick a screwdriver down the barrel to hold open the choke so it would start. That was a great vehicle though.....Look forward to seeing your progress here...

 

[Bajablazer85]

I'm glad you're all liking it so far. I've got a ton more to post, the build is currently several months ahead of what I'm posting.

Man does this bring back a flood of good memories; I had a 1984 GMC S15 as my first vehicle. I too had the 2.8 liter (turd) with crappy Rochester carb. On cold mornings I would have to stick a screwdriver down the barrel to hold open the choke so it would start. That was a great vehicle though.....Look forward to seeing your progress here...

Tell me about it, I don't know what GM was thinking with the Rochester feedback carbs. I rebuilt mine twice and it still ran like garbage. A common problem with them is warpage, allowing a vaccum leak at the intake manifold surface. Anyways....besides the powerplant, they were very decent trucks!

 

[rkj__]

Cool!

My dad had a Jimmy 4x4 from the late 80s, before it got rear ended, and wrecked. He like it a lot, but often commented it was a little gutless in the power department when towing.

You are off to a great start with the engine swap!

I'm looking forward to seeing this build progress.

 

[Bajablazer85]

Post #5 - Front Suspension and Steering

As I briefly mentioned above, the original IFS system was pretty beat by young male driving habits. All the bushings were dry, creaking and sloppy. Steering had about 2" of play before any real feel (if you can call it that) occurred. At one point, the front wheel on the driver's side had ejected itself while traveling 35 mph, causing the ball joint to be ground down to a flat nub. Lesson learned at the time: always torque wheel nuts after doing brake jobs!

I want to stay away from extreme changes such as SAS. Similar to why I don't want a v8 swap, I don't believe it's in the character of the truck. Additionally, when the IFS works, its actually pretty nice. Ride, comfort, and handling are traits I'd like to retain.

The plan will be to replace all wearable items and add a 2" lift so that I can run 30" tires. The 2" lift will come from Superlift and includes re-clocked torsion bar keys, upper control arms, extended bumpstops, and all the necessary hardware to accomplish the task. For the rear, Superlift provides a lifting shackle for each leaf spring. Very simple.

For steering, all wearable items will be replaced along with the steering box. A steering stabilizer will be added for better feel.

Everything that wasn't replaced got washed and a coat of paint.

I decided to go with polyurethane red bushings in the front. I had previously installed poly bushings in the rear suspension leafs, and the improvement was staggering.

Due to the poly bushings tendancy to creak, I chose to add zerk fittings to all the joints. Future serviceability will be key to extending the longevity of the vehicle. Hopefully I will be able to mitigate creaking when (if) it arises in the future. I only needed one 1/4-28 tap, but got a whole cheap-o Harbor Freight tap and die set because why not.

The "new" (rebuilt) steering box came with a lot of play in it. Using an allen key and a 16mm wrench on this fitting will get the adjustment close.

Lastly on the front, my friend welded the lift kit shock relocation brackets to the frame, and I welded my initials in the front frame rail.

For the rear suspension, I got some zerked bolts and installed the rear lift shackles. Bolts are from from Mountain Offroad Enterprise for an XJ Cherokee, which have nearly the same leaf springs as an S10. In college, my buddies would buy S10 leaf springs from the junk yard and re-sell them on craigslist as lift springs for an XJ Cherokee. Their secret is out, and I'm not sorry ¯\_(ツ)_/¯

The zerked bolts come with the bolts, nuts, and bushing sleeves for the grease to travel to the rubber bushing. You must reuse the S10 washers.

Installation onto the leafs was quite simple. But getting them into the frame bushings is a thing I would prefer to not talk about again *shudders....*

 

[Kevin108]

I had an 85 S-10 in high school and early adulthood. Wish I could find it now. With 20 years of build experience and a significantly better budget, I think I could make it everything I always wanted it to be. Can't wait to see how your build turns out!

This was from 2002. My red S-10 is 2nd from the left and 4x4x4doors' white Blazer is second from the right.

 

[case]

I'm enjoying this thread. S10 Blazers are pretty versatile and don't normally get much attention or respect.

I DD'd an '87 2WD for four years that was bought for $250 with the intention of just using it for a few months until I got my XJ fixed. Even with a weak 2.8 and 2WD on stockish sized tires it went a lot of places it probably shouldn't have.

 

[Bajablazer85]

I had an 85 S-10 in high school and early adulthood. Wish I could find it now. With 20 years of build experience and a significantly better budget, I think I could make it everything I always wanted it to be. Can't wait to see how your build turns out!

This was from 2002. My red S-10 is 2nd from the left and 4x4x4doors' white Blazer is second from the right.

Wow, there are some awesome looking S10 platform vehicles in that photo. That Bravada included

 

[Bajablazer85]

Post # 6 - Rear Axle (Part 1)

I'm super happy you guys are liking this build! So I'll keep posting.

Rear Axle - Part 1 - Differential.

Plans for the rear axle will include disc brakes and a GM OEM G80 locker. Original equipment in my particular Blazer included drum brakes and a completely open rear diff. The reasons for swapping the open diff to a limited slip should be pretty obvious to anyone who goes offroad. But the G80 in particular was my choice of locker since it's original optional equipment on these rigs. While this is to be a functional build, I also want to stay true to it's roots. And, hey, if I find the G80 turns into a weak point, I can still change it to something better.

With the rear axle removed, I drug it to the local self serve pressure washer to clean it up.

Front frame clip worked great as a workbench for this phase!

The G80 limited slip locker came from a local junkyard, out of a 1992 Blazer. The splines in this carrier are 32, whereas my open diff is 28, so I gnabbed the axle shafts as well. In addition, my Blazer is a 4.11 ring gear, from the factory. I will have to move my 4.11 ring gear over to this carrier.

Once I had a clean canvas to work on, I began putting everything back together. Setting the rear diff was a fun learning experience. I had never done it before, and I want to learn as much as I can from this build.

Everything came out in spec. As it should, using the original shims and ring gear...just on a "new" G80 carrier....

Buttoned up and ready for part 2...

 

[Bajablazer85]

Post #6 - Rear Axle (Part 2)

Rear Axle - Part 2 - Disc Brakes.

While the drum brakes were certainly competent, they are also plagued with what I consider to be design flaws. Heat dissipation and complexity are a few deal breakers for me. The Right Stuff's rear disc brake conversion kit is complete with 1979 El Dorado calipers and 1979 Firebird rotors. Their bracket is completely bolt on except for the brake line tabs which need to be welded. To this day I still havent gotten around to welding those on, so just pretend its done!

After the differential was reassembled, I got started on the fun stuff. I mentioned in my first post that this build was a long time coming, and I was looking forward to these moments for years. It's amazingly satisfying when you get to achieve your goals and implement your plans into action.

"Completely bolt on" is never completely true. This big bolt on the top of the bracket in this picture had to be ground down so the disc rotor wouldn't contact it. This bolt is under shear, not under tension loading, so should be okay with the grinding.

One massive complaint I had is the hardware included isn't enough for The Right Stuff's torque specs. They wanted me to put 25 ft-lbs everything, and the smaller bolts broke during installation. Replaced everything with grade 8.

[EDIT] Everyone keeps telling me I should have found an Oldsmobile Bravada with the same gearing as my axle and thrown that in with the same results (disc brakes, limited slip) instead of the work I've done with my old axle. I was not in a position to acquire an entire second axle, let alone store it in the space I had. Building and working with what I already had was way more fun. After all, I do this for fun, or I wouldn't do it at all.

Part of me wanted to clear coat everything. I love shiny things! But this isn't a low rider. I finished up with a coat of black paint.

Yes, I painted my rotors. I'll have them turned down just enough to cut the paint off the braking surface. I just hate how rusty rotors look, so I'll do what I can to prolong that.

Back in the truck. Also got some Superlift shocks. These shocks were supposed to be included in the lift kit, but for some reason the lift kit was parted out into three different part numbers. Superlift must have been running out of these kits and they're clearing out their backstock.....

At this point, I'm still posting retroactively, so I'll continue with posting the engine build, and more!