#minijimmygmc Wifey's 1990 K5 Jimmy rebuild

[chevy3100truck]

So my wife decided late in 2016 that she wanted to ditch her Trailblazer (truly hated that thing) and get a square body Blazer/Jimmy or Suburban. I ended up trading her Trailblazer for an 86 Suburban (which has parts from at least 3-4 different trucks on it) and some cash to buy a project for daily driver.

Finding a K5 that wasn't completely rotten around here is virtually impossible, so I just took the best I could find at a sane price ($2500 - Canadian). From the records I got with it, it looks like it had 1 owner from 1990-2012 who kept all the service records. It was then sold to a guy who added the lift & tires as a weekend mud toy. Had 160,000KM (100000 miles) on it. Typicaly 350/700r4 setup, dealer installed AC that sort of worked (I really didn't think dealer installed AC was still a thing by 1990 but apparently it was....)




My daughter decided it would be called the "Mini-Jimmy" since she thought it was small and cute lol. Well, it is a lot shorter than the Suburban but it was sitting on 38" Swampers with a 6" lift......

Needless to say, it didn't look too bad, but I knew it had it's share of warts.


It was really fun to drive home on snow & ice covered roads with the swampers and a stuck drivers side front brake caliper....

So - first things first - gut the interior - how I hate red interiors.....

[chevy3100truck]

So out comes the interior, not much left of the floors & sides of the cab behind the front seats as expected (there were some lousy attempted repairs by the previous owner).






I was surprised at how good the rest of the floor looked however considering it didn't have a tailgate window (who knows for how long) and being as it was winter when I picked it up, the inside was full of snow & ice lol. The drivers side tailgate post was also a mess......

[chevy3100truck]

First things first - have to fix this mess -




Cab mounts were replaced on both sides from where the material was good (not all the way across the cab, but a decent portion from the rockers in towards the center) For the floor panel replacement I didn't bother buying repop panels as the worst area was a flat section with a drop off towards the rocker. I would have just ended up cutting up new panels and then still having to fabricate a bunch, it was just as easy to just patch everything together - it's not a show truck, just meant to be a daily driver.




A bit of grinding to clean up the ugly stich welds and some seam sealer to make sure it's all water tight



I put back a seat belt mount where it was rotten on the passenger side (rot was cut out below the mount on the drivers side) however I wasn't going to be using these mounts after upgrading the seats.

[chevy3100truck]

The rotten tailgate post was the next thing to get attention -


a bit of cutting and using a trimmed up patch panel and we get this -


Some more repairs in the taillight cavity, not too concerned about looks since this will never be see with the taillight in the truck. Just had to be functional and cut out all the rust that was there. This side had a bunch, the passenger side was completely clean.

[chevy3100truck]

Next up - getting the seat mounts in for the 2005 Yukon Denali rear seat. This was a split 3rd row that I picked up off of craigslist. One of the issues with a 1990/91 K5 that separates it from the earlier ones is that the rear seats have 3 point seat belts with an attachment on the roof. Basically - you can't take the roof off and have seatbelts.... (and using 2 point belts in the back would lead to issues if we ever had to take it through inspection).

Being as my wife wanted a K5 for the ability to have the roof off we needed a different solution for summer time. The Yukon seats with built in 3-points were the best solution, and being leather was a bonus for sure. It helps that they are about the perfect width for sitting between the wheel wells on a K5.

These pics just show the patching where the old seat mounts were, but there are 1/8" thick steel plates underneath the floor spanning all the way across the tub under both rows of mounting brackets - if the seats come out they are taking the entire floor with it. Where the floor is raised there are spacers between the floor and the steel backing plate, I wasn't going to try to make the backing plate conform with the corrugated floor.






The front seats are out of a 2001-2007 Chevy Silverado for now, picked up some cloth power seats for $20, then found $12 in the console lol. Not the ones I want, I need to find 1999-2000 3-door truck seats that have the rear lever for tipping them forward, but the price was right. I actually took a pic of the steel backing pieces for underneath the floor for these seats, 2 pieces for each seat, bolted from the bottom to the factory seat mount bolt locations, and then the seats are bolted down from above through the floor and the 1/8" thick plates.

[chevy3100truck]

The floor now needed to get a bit of paint, so I used Duplicolor roll on bedliner to coat the entire floor since a local liquidation place was selling it for $5/quart. I wouldn't have trusted this stuff for an actual truck bed, but for the interior it adds some mass to the floor to help with acoustics and block a bit of heat.




Added some Eastwood X-Mat acoustic insulation, their equivalent to Dynamat, to some areas of the floor before covering it all in a cheap aluminum backed polyurethane heat insulation material.




Vinyl floor went in (no more carpet!) & the rear seats dropped in. (The vinyl floor need to relax more, I was installing this at night when it was cool outside)

[chevy3100truck]

Since wifey wanted to drive the truck last summer it was just going to get enough updates to get it on the road.

Unfortunately that meant replacing the front axle as the ball joints were shot, the pinion bearing had a bunch of play, the hubs were garbage etc. Apparently running 38" swampers on half ton axles to play in the mud isn't good for them lol. Luckily a friend was parting out an 89 Blazer that had good axles in it, so I grabbed those and swapped the front one in (with no driveshaft since the ratio didn't match the rear now - but the rear is being swapped this winter with a complete re-do of the rear suspension).

New brakes all around and we sold the pretty much bald swampers and changed to 35" x 13.5" r17 Nitto Terra Grapplers

[chevy3100truck]

So now that gets us to last summer, got the truck insured and driving (albeit in 2WD only - but it's going to be a mall crawler anyhow lol)



And with the top off after installing 1 1/4" wheel spacers on the rear to get rid of some of the "tucked in" look (which I hate - I understand why it was done, but I hate the look)



and one shot with the wife's summer only car - 1969 Ford Falcon sport coupe


So after a couple thousand kilometers over the summer, some changes needed to be made....... I'll post some more about those soon.

[Palf70Step]

The mini-Jimmy is coming along very nice. Can't wait to see what else you do to her.

[chevy3100truck]

so when the truck has a 6" lift, 35" tires and you have old school swing out doors that only have about 6'6" clearance you have to get creative to get it in the garage for the winter - and not care about the beat up old asphalt driveway too much lol



Drove it in on it's own that way on just the junk wheels. Only left a few grooves in the asphalt..... didn't hurt the concrete floor in the garage at least.

Once it was clear of the door I could put it on dollies and move it around - just have to be careful not to hit the tracks for the garage doors as they are bloody low.

[chevy3100truck]

so the truck had an oil leak, and had the typical blue smoke on startup, so I figured this was the appropriate way to deal with it



Got my trusty assistant to give me a hand.....


and tear down the engine

[chevy3100truck]

Just a quick and simple rebuild on the 350 - new rings & bearings, new slightly larger than stock cam, and freshened up heads. The bearings that came out of it were all in good shape with the exception of the cam bearings - they were ugly. Being as I'm leaving it with the factory TBI for now, not a whole lot I can do to the engine without having issues (well, not without throwing money at it which I don't really think is worth doing with the factory TBI)



mostly complete - accessories, water pump, brackets etc. will go back on once the engine is back in the chassis


Sandblased & painted the accessories etc as needed. Had to get a friend to weld up one of the accessory drive brackets as it had a crack in it. Also learned a valuable lesson - after you degrease & pressure wash a bracket that still has the tensioner on it don't leave it outside for a week, the bearing will rust up really nicely lol (I can't believe I did that - I meant to bring it inside, but forgot it with some parts I was storing outside)

[chevy3100truck]

I had pulled out the funky ARA dealer installed air conditioning, it sort of worked, but I think it had as much leak sealer in the system as it did refrigerant. I didn't realize that dealer installed air was still a big thing in 1990, but the Jimmy was pretty bare bones with manual windows & locks, only a power rear window.

So I sold this pile of stuff to a guy who just wanted the engine compartment box that adds AC to a non-ac inner heater box.


Since it is the wife's rig, and she really wanted AC (even though the top will be off most of the time when it's hot out.....) I ordered a complete Vintage Air kit for it. It will be way cleaner in the engine compartment, and quite frankly I hate dealing with the vacuum operated doors on the factory stuff...

Block off plates for the vintage air installed -


Interior also got gutted again -

[chevy3100truck]

I managed to roll the front of the truck outside for pressure washing the frame prior to a bunch of wire wheeling & sanding to get the frame cleaned up. This thing had been a mud truck when we got it, so there was silt and dirt everywhere (the mud line on the inside of the door was up around the door handle, so it had been submerged pretty good at one point.....)



OK, I did get it cleaner than that prior to painting. I feel like a used car lot guy using Tremclad spray paint to detail the engine compartment, but its just going to be a daily driver, so no need to get fancy.



The steering components are all going to get replaced with the exception of the box, so I wasn't worried about painting that stuff or the brakes for now. Also have the Off Road Design steering box braces to install still

[chevy3100truck]

So the factory inner fenders were typical for a square body.... complete garbage..... So I bought some cheapy aftermarket inner fenders for the GMC and painted the engine compartment side and undercoated the inside. I detest the little plastic Christmas trees used for attaching plastic parts, so I cut out some new rubber splash guards and used SS allen bolts to hold them in place. The rubber I used might have been a bit to thin (3/32"), but I can always swap them out later if necessary.

[chevy3100truck]

so next up was tackling the engine compartment wiring harnesses (as you can tell there is no rhyme or reason to my order in doing stuff sometimes, just depends on what I feel like that night lol.)



I removed all of the original split loom, and shockingly the harness had never been messed with. Other than a lot of dirt inside the loom, there were no cut wires, no damaged insulation, nothing. It was all in perfect shape, so I just wiped down all of the wires and put new split loom on all of it. I'll end up modifying the light harness when it all goes back together and add relays near the lights and set it up so that when the high beams are on the low beams stay on (not a fan of the either/or setup with a 4 headlight truck)

[chevy3100truck]

So the Jimmy had 2" lift springs in the rear with 4" blocks when we got it, I know that setup is OK, but I've never liked big lift blocks. Even with the weak 350 in it you still had a bunch of axle wrap when you get on the throttle. So since the axle had to come out to get changed out to the new to me one, I decided to switch the lift to an Off Road Design shackle flip kit.

Before that goes in though there was a whole bunch of scraping to remove the original undercoat from the truck. At least it was easy to get a lot of that cleaned up since it had gotten hard over the years and really wasn't adhered to the frame rails, wheelwells or the bottom of the floor much at all.

lots of piles like this -


to get it mainly like this from scraping -


then lots of wire wheeling and cleaning before applying undercoat to everything underneath the truck. Before doing that however I ended up replacing most of the inner rocker on the drivers side, after scraping off the undercoat on that side I found some rust, so I figured it was easier to fix it now than to wait until it gets worse. The passenger side was mint however, so it just got cleaned up and painted.

[chevy3100truck]

so you think it might need new leaf spring bushings? lol



So I wire wheeled the leaf springs and threw a quick bit of paint on them to hide the ugliness, same with the new to me rear axle. Once the axle is in I'll put on new brakes, brake lines, etc.



Installed the Off Road Design shackle flip kit, ORD shackles and greasable polyurethane bushings. I have to say the shackles are a whole lot beefier than stock ones (one of which was bent). I'll have to get the axle installed and figure out where it is in the wheel opening since the shackle flip moves the axle ahead a bit. I've got a set of the ORD "inch" blocks to adjust the position of the axle as well as their 1/4" thick plates for adjusting axle position (inadvertently ordered the inch blocks, but shipping them back to the US isn't worth it, so I'll use them if I need them, if not they'll go on the shelf for another day)

[chevy3100truck]

so that's basically where the truck is at right now, I pulled it into the garage in late October and I'm hoping to have it back on the road by the end of May. Had a couple of other projects get in the way in between working on this one that took up some time -

A mini quarter midget race car built out of polished stainless steel for our year end racing banquet silent auction (this car is about 10" long tip to tail - I'm not good with detail work and its basically all cut out with a 4 1/2" angle grinder, lots of filing to notch the 1/4" tubing, and SS wire in a mig welder - not the best way to do things, but it works lol)



Next, I had to build a couple of new ugly drum smokers for Christmas presents (I had built one for myself in September and a couple people really wanted to try them)

[Palf70Step]

Work looks good. Your mini miget looks great.

[chevy3100truck]

Installed the rearend in the truck for a test fit, it'll have to come out again once I figure out the wheelbase adjustment needed due to the shackle flip kit and the pinion angle once the engine is back in (stupid me didn't bother to check the angle at the transfer case before I pulled the engine).



Finally removed the rear bumper & tailgate, someone at some point had thought it was a good idea to weld a bumper bolt in place instead of, I don't know, replacing the bumper bolt or finding the right nut for it....... Ordered up new bumpers anyhow as this truck had the style with the rubber strip across them which I'm not really fond of.

[chevy3100truck]

more detail stuff - with the tank out I scraped off all of the old undercoat & cleaned off all the mud so I could repaint the tank & straps.



Figured I might as well pull the filler neck out now since it's coming out for the repaint anyhow, ended up having to wire wheel out some rust around the filler neck & primed then sprayed it with a bit of undercoating. It can be ugly since no one will ever see it lol

[chevy3100truck]

Hopefully this weekend I'll get all the new steering parts in as well as the Off Road Design steering box brace. Then maybe get the bumper brackets painted, get the tank installed as well as the trailer hitch then eventually move on to bodywork.....

[chevy3100truck]

Well, Saturday was one of those days when you seem to work all day but don't really get what you wanted done accomplished....... Removed the windows, 2 out of 3 successfully lol. The windshield had a chip in it which became an instant spiderweb crack as soon as I put a bit of pressure on it to get it out of the seal, so I guess I'll be getting a new one of those ordered in

Gas tank and hitch got installed, taking way longer than it should have (had an argument with the gas tank straps, for whatever reason they were very hard to get stretched out enough to get the first thread started on the bolts - operator error I know)



Sunday, well, at least we finally got around to putting in the new steering components as well as the steering box bracing kit from Off Road Design. Unfortunately, we also figured out that I had ordered the wrong front shocks from ORD, and now would either need to return & exchange them or add mount extensions. Since I'm in Canada, return shipping is going to be pretty much just as much as getting the F250 shock brackets, I figured I'd just order those, hopefully will have them for next weekend.

[Dads79GMC]

Awesome stuff!!! Looking good!!!