70 Jimmy--Rusty Rebuild

toomany

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70 Jimmy--Rusty Rebuild

Starting a new thread for this 1970 GMC Jimmy I just picked up. I won't be doing a complete restoration, but instead rebuilding it into a nice driver. Something to hop in on nice days and go for a cruise. I'm going to be doing a lot (and I mean A LOT!) of metal replacement. Truck needs floors, rockers, rocker boxes, floor supports, A and B pillars and quarter work. I did get some patch panels and a good chunk of a donor cab to fix the "4 hole" area, along with what looks to be a cut down truck door.


It's about as stock as I could hope for. Drum brakes, points, etc... What isn't stock is period correct, the 6lug16.5's, the aftermarket tape deck from the 80's, aftermarket plow, brace under the front axle. 350/465/Dana 20, D44/12B. Took me a minute to figure out how to shift into 4hi/lo from two wheel drive.


https://ck5.com/forums/threads/new-70-jimmy.326433/ Is the thread I started when I brought the truck home. So far I've gotten it running, and it actually runs very well. Fires right up and settles into a low idle (I'd guess 700rpm). All the gauges work, all exterior and dash lights work, heater works, plow controls work (not staying though), steering, clutch, transmission and t-case work. The brakes are non existent though (maybe why there was a gallon jug of brake fluid behind the seat). So far it hasn't leaked anything after getting it up to temp a few times and driving it around the yard....so either everything is empty or it's got decent seals still.


I'm not looking for all out off-road performance, nor am I looking for 100% factory correct. I want what works well in day to day driving. The problems I've had in some of the last few trucks will hopefully be avoided here. Making it hard to drive or uncomfortable means you use it less...not what I'm after. Some things will be upgraded, mainly the drum brakes up front. I've got a nice 10B with locker that is ready to go that might find it's way under the front, have a 6lug SF14 that might end up out back. The 4speed may or may not stay. I've been holding onto a Nv3500 (and an extra Nv4500 around too) for a build like this, have the correct passenger drop t-case for it as well. Nothing is set in stone as I've got a while before I get to that point. EFI or even LS might happen too, I have a complete TBI or TPI system to choose from.


Plans are to get the body braced up and the passenger door on before pulling the body off. Once that's off I'll go through the frame, new brake/fuel...

Read more about this build here...

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Bent77

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Really it's in pretty decent shape for a 1st gen Jimmy
:popcorn:
 

Phil513

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I get what you said about the 16.5's. I love those wheels, but yeah, not a huge tire choice.
 

toomany

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Started doing some small stuff on the Jimmy. It's in the wrong bay of the barn to start really tearing into it, so I've been cleaning it out and taking small parts off. Plus we've been having 90* temps the last few days so I haven't been real motivated to get out and do things on it either.

Pulled out the floor mats/rubber liner and swept out the back end. Cleaned out the cowl vent too, lots of stuff up in there. Both sides are getting thin around the sides where everything collected over the years. Rear floor is okay for the most part. Has a couple patches already that will probably get replaced again. One area has sunk down where the crossmember collapsed underneath. Wheel tubs seem solid. Both front floors will need to be replaced, along with rockers (inner/outer), rocker boxes, floor supports. In my other thread, @handloader90 dropped a link to a replacement floor with all the supports in it already. ( http://www.motorcityk5.com/rearoute...azer67-72suburbanandckpickup-1-1-2-2-1-1.aspx ). It doesn't have the rocker boxes on it, but I still think that will be the best way to go about getting a solid floor again. Plus they are right down the road from me, so I can make the trip down there to pick up in person to avoid shipping costs.

The worst part of the truck is the passenger side lower A-pillar/floor area. This will be the first major thing I tackle before popping the body off (want to get good metal in there to brace to). Luckily I got a good chunk of a truck cab to replace that part. I will defently use the A-pillar and probably some of the rocker/floor. 40 year old GM parts fit better than new aftermarket stuff...and being there are so many panels that come together in that area, having factory pieces there will make it go together easier. Even if I end up cutting some of the factory parts away, I'll have a good reference as to what correct the measurements are supposed to be.



Shot of the bed floor. You can almost make out the weld line where the rear 4" have been replaced before.




Piece of the donor cab. Real solid for the most part. The A-pillar is mainly what I'm after. What rust is on the bottom is just surface stuff, should clean up decent.








The giant hole where the Jimmy A-pillar/floor/rocker/box used to be. This is by far the worst area of the truck. Pretty much all the support is gone in the area. I can't say for certain, but I'm pretty sure the body has sagged some on this side. The door opening looks correct, but I haven't measured it or tried putting a door in it yet either.





Because I was curious, I pulled the plate around the radio off. At first glance I thought it was an aftermarket piece, but after looking at it....it's not. The sides are rough cut/unfinished and the hole isn't exactly square. Removed the plate and found that they did cut the dash...but it's not too bad. Just a little bit where the new radio was too narrow for the opening. On the plus side, it's a Delco radio and it works....even found a "Bad Company" cassette in the glove box.







In the next few days I plan on pulling the plow stuff off and probably the core support/inner fender.
 

toomany

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Pulled the plow carriage and hydraulic parts off this afternoon. Broke almost every bolt holding the thing together trying to take them off. Didn't notice it at first, but the factory bumper has a small dent in it from the lift cylinder hitting it. Should be able to straighten it out easy enough. On the driver side they used a bunch of washers to space the bracket out around the brake lines, on the passenger side there is a big plate welded to the frame. Not sure if that was supposed to be a spacer or if the frame had ripped at one point. It's at the point that would be taking all the load from the plow when pushing, so who knows what I'll find when it grind out the welds.

Couple quick pics of the cleaner front end/engine bay.






In the next couple days I plan on switching the Jimmy and S10 in their bays, then I can get going on the A-pillar.


Edit: It looks lopsided in the picture because the drivers rear tire is soft and the grill is just haning there by one bolt on the passenger side and is swining away from the truck.
 

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Had to work more than I wanted to today (7a-1p, then 5p-9p), and I didn't want to get all wet/dirty washing the S10. So what do I do instead on my couple hour break? Get dusty and dirty working on the Jimmy.

Found some measurements online (both here and over at 67-72), pulled the same measurements off my body. And like I figured....it's way off. Maybe way off is going a bit far, but it's about 1/2" off from some of the dimensions I've found. Now who's to say that those were correct anyway. Measuring my driver and passenger sides, the passenger side firewall had fallen forward about 3/4". That's without either front fender on to help hold it in position. Measuring the chunk of cab that I have, both side actually measure out correctly from the lower A-pillar to the B-pillar....so that's a plus.

I used a ratchet strap to pull the firewall back to get it the same as the drivers side. That side (drivers) door fits reasonably well. The gap at the B is a little larger than I'd like, but it's straight/consistent and doesn't have an abnormal amount of shims in it so I think I'm okay to match that with the passenger side. In fact, the hinges on the drivers side don't have any shims in them at all, so the door could be moved back to align better with the B-pillar. Once I had the firewall where I wanted it I put in a brace. From the top of the A-pillar to the striker plate, already hit my head on it twice. I did order a factory assembly manual last Monday (the 20th). Hoping it'll have some numbers in it I can use. Thought it'd be here by now, Amazons tracking blows and say its been shipped and will arrive by July 8th :surepal:. Before I get too far with putting metal back in, I'll pull some measurements from my friends 68 K10, I know that one hasn't been dicked with and is still straight.

I pulled the heater box and transmission cover off. In the pictures, you can see the lines someone put on the floor where they were going to cut it. I don;t plan to follow those exactly, but I'll be close to them. I want to use as much of the green floor/rocker/A-pillar as possible, even if I end up cutting some of it back out later down the road. Reason for this is, it's factory so if I can keep it in one big piece, I think it'll be easier to get it in the correct spots. There are a few common bolt holes I'll measure from to make my cuts along with the changes in the profile of the metal. It should go back together fairly simple.


Shot of the passenger door brace. Will add one on the drivers side before I get much further.




Dotted lines are from the PO. Plan on cutting about as much as they did. Will use the shape of the transmission opening as a reference point. If I can...I'll keep the patch one piece and tie into the A-pillar at the same time.




They had enough fore-site to cut the cab almost in half, leaving part of the inspection hole flange. This should be a good guide when lining it back up.




In other news, I'm pretty sure the Jimmy has some kind of lift on it. Has a 2'' block in the back and 4 leaves in the front packs. It sits fairly level and clears the 33's decently too. I'm guessing the taller front springs were to help with the weight of the plow. I don't plan on ever going to a bigger size tire, and it looks like it'll clear the door to my other garage at it's current height. Probably will end up taking the springs apart, cleaning them and reinstalling with new bushings. The little bit I did drive it around the yard, it seemed to have some movement from them. Unlike some of the other super stiff lift springs out there. I think with a good shock it might ride okay.
 

toomany

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Finally found some time to work on this. Been real busy with work and the other truck lately. Started cutting out the passenger side floor. Not sure if it's had repair work before, or if what I found was the remains of the factory rocker boxes, a lot of heavier angel iron was in behind the outer rocker. It looked to be decently done so I dunno about it....didn't think to look at the drivers side to see if it had it too.

Couldn't figure out how I wanted to go about cutting the old floor out and getting the new one to match up. So I just started hacking away with the grinder till I had a giant hole. Then I went to town on the green floor till I got something that fit the space I had created. Still need to trim back the A and B pillars on the Jimmy, along with some of the floor, but for the most part....it's in there. There are a few areas cut out that will be easier to replace separately later.

When I started cutting.




Little bit further, pile under the truck is growing.






And then new one sort of fitted into place.








You can see how most of the edges are still overlapping each other. Probably take me a few hours to get everything dressed and ready to weld into place. Need to take some time when I cut into the B-pillar too, only want to go through a few layers.
 

Bent77

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Slow but easy wins this race
 

toomany

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I'm in no real hurry to get this one done.

In all reality, most of what I'm putting in now is going to come back out when I drop the one piece aftermarket floor pan in. Using the green one first was just to make sure I got the body back where the factory intended it to be. I know for a fact that the A-pillar area will be staying though. Because the door and fender both attach to it...I wanted to be positive I got it back in correctly.
 

toomany

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Got the new piece all fitted and tacked into place. I need to make up a few filler strips to fill some gaps. But as it is now....I think it's in there well enough that I could go ahead and start pulling the tub. I'll probably finish off the A-pillar are first though, as that spot is going to stay not be cut again. Forgot my phone in the house so I didn't get any pictures tonight.
 

Bent77

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Got the new piece all fitted and tacked into place. I need to make up a few filler strips to fill some gaps. But as it is now....I think it's in there well enough that I could go ahead and start pulling the tub. I'll probably finish off the A-pillar are first though, as that spot is going to stay not be cut again. Forgot my phone in the house so I didn't get any pictures tonight.
It's been a day, where's the pictures?!?!?
:deal:
 

toomany

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It's been a day, where's the pictures?!?!?
:deal:


Found some time to get out and mostly finish off the A-pillar. Made up a few strips to fill some gaps. Only after I got the one in and started flap wheeling it down did I realize I should have done the one differntly. Had some pin holes show up in the metal under the vent in the kick panel. Will probably cut that stuff out and add another new piece next time I get out there.

Had to cut a thin sliver piece for the post. That part is basically done. I didn't grind down the inner kick panel much because I'll probably end up back in there welding again.


Tacked in. Knowing I was going to cut the floor out, didn't try too hard to get the parts super close on some areas. Used the transmission cover and body mount hole to help align everything....got all the bolts in.




B-pillar area. Had to do some weird sectioning to get the truck cab panels in place of the K5 stuff. Have a line on some decent bedsides from a guy over on 67-72, just trying to work out the shipping. Not going to go too crazy welding/finishing this area until I have some new metal to go back on.




Shot of the A-pillar before filler strips. To get the door hinge bolt holes the correct distance from eachother I had to cut a little more than I'd have liked. About a 1/4"-3/8" gap in the kick panel.




I put an "L" shapped piece of 16gauge on the backside of the gap. Filled in with a bunch of tack welds. Only after getting it mostly ground down did I figure out I should have just done a bigger square patch.




Same area after some flap wheel time.




Post area. Ground down a strip of 16gauge to fill the gap. At this point I think I cleaned up the first tack welds already.




After a few tacks.






Welded up.




And ground down.




I might finish out the A-pillar/kick panel next. Or start pulling parts to get the tub off. I'm fairly comfident that the firewall isn't going anywhere on this side. Need to put a brace in the drivers door before I get the tub moving.
 

toomany

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Decided to start filling in the gaps in the upper part of the floor. The replacement floor I plan on getting doesn't go that far up, only to the seem just in front of the body mount.

About a quarter/half inch gap most of the way around. Cut some strips and welded them in. Only did two so far. Didn't grind anything yet either. Neighbor was having a birthday party for their kid and I figured they didn't want to listen to the grinder, was too hot to work with the doors closed.

What I started with.




Where I stopped.

 

toomany

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Got rained out from washing my other truck (the S10), so I went into the barn and did a little more work on the Jimmy.

Finished the upper floor on the passenger side. Think I ended up with 5 more individual pieces to fill in the gaps. Could have done it with fewer, but the way the firewall and my cuts curve, it was faster/easier to do smaller pieces. Hit everything with the flap wheel to knock down the welds. Could take everything down level with the floor, but odds are it's going to get covered in some kind of liner or carpet eventually so I wasn't going to spend too much time on it.

Need to come back and finish off the A-pillar, both inside and outside. Think I'm going to wait on that till I get the tub off...then back on. Going to measure door openings again, adjust if needed, then weld a brace in the drivers side opening. Once that's done I'll start pulling body bolts and get the tub lifted off. Probably going to build a wooden cart to set it on so I can move it around/out of my way.


After getting everything welded in.






After a few minutes with the wheel. Pulled some of the firewall pad off because I kept setting it on fire with sparks. Was awkward trying to get into a good position with the grinder to where I could see and move at the same time. At some point I'll be pulling the dash/firewall stuff. If I decide to finish out the grinding....that'll be when I do it.

 

toomany

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Pulled the most of the front end stuff off today. Core support, radiator, wiring, inner fender. At some point the core support bushings had been replaced as they are poly. I'm thinking it may have been done when the truck was taken apart to fix a tear in the passenger side frame rail from the plow. I also think the inner fender never got put back on for that side at that time too, which would explain why that side of the truck was so far gone.

Next time out I probably get going on pulling the motor and disconnecting everything underneath the truck....I didn't feel like getting that dirty today.


Where I left it today.







I know it's a ways off, but I picked up (literally) some seats I'll probably use. Was getting ready to leave work today (I manage a bar/restaurant) when one of the regulars told me about some seats out by the road over near his house. He said the guy has a few Jeeps and that's most likely what they came from. There was a fairly built TJ in front of the barn, I'm guessing that's what they came out of. They don't have any rips and no real stains. Might end up replacing the cover anyway though. Not wanting to give up an arm, leg or first born for a set of correct K5 seats, these should do nicely.

 

toomany

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Pulled the drivers door off and the steering column out tonight before I had to head back into work. I knew the drivers lower A-pillar was soft but I didn't expect it to twist off when I was loosening the hinge bolts.

 

78K30

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You definitely work fast! I'm liking where this thing is going
 

toomany

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Real productive night today.

Started out with pulling the exhaust off. Was expecting to break all the studs on the manifolds but only one broke. Not sure if it was factory, or where they had the new pipes put on, but the nuts were brass and weren't corroded too badly. Cut the pipe just behind the transmission crossmember so I could get the Y out easier.

Next I moved on to the body mounts. I didn't even try breaking them free. Went straight for the cut off wheel for the carriage bolts, used some vicegrips on the nuts for the regular bolts and just snapped them off. At some point the body mounts/bolts have been replaced. Most of them were all thread with some nuts welded (poorly I might add) to the top to make a bolt. They were under some tension because when they snapped they all made a loud pop and you could see the floor lift some. Tub is basically ready to come off. Need to disconnect the fuel filler, e-brake cable and brake lines still.

I was planning on calling it a night after fighting with the body mounts, but then the wife called and said she was going to go somewhere with here mom and daughter so I had some more free time to kill. About an hour later I had the motor out and sitting off to the side of the truck. I could have left motor in to roll the frame out, but then I would have to lift the body even higher...and it was going to come out anyway. I will say that for as old as these trucks are...there isn't hardly any clearance for the upper drivers side bellhousing bolt. Usually on something this vintage there is miles of room.


Coming out.





Bare front end.





Different perspective of the truck. I had to get onto the top shelf of my motor shelves to get the box down with some of the replacement metal I got with the Jimmy so I snapped this picture real quick. Gives an overall shot of the area I'm working in.





Tomorrow or Thursday I'll get some kind of cart built to hold the body, then I should be about good to lift it off and wheel out the frame. For a cart I might pick up some big casters, some furniture dollies or some wheel dollies and build a platform to sit on those. Not entirely sure which direction I'm going to go in yet. Have to wait till I get to the store and figure out the cost of each option and the usefulness of the parts after I'm done using them for this task.
 

70jimmy

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In the pics it looks like your tranny tunnel cover is still on. Taking that off makes the upper bell housing bolts easier to access. I see you braced the passenger side door, but not driver's side yet.

You work pretty quickly. Looks like you have a nice space to tear it apart!!! I will be following this thread!!
 
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