Took the sawzall challenge

[mechanicalman]

Finally got up the courage to cut the LWB frame down, have a SWB frame in reserve so nothing to lose.

Moved the suspension cross-member ahead 12" using a 12" standard strap and using the strap on the underside of the frame for a drill guide on the lower holes, then drilling the upper holes with the member in place using it as a guide.

Pictured below are two 12" standards and one 24" standard, the long bit needed and a nifty 3/8" guided center punch made on a lathe. The extra 12" standard and the 24" standard were used to shorten the frame.

[BruthaMan]

Looking good! Subscribing. For all the great mechanical advice you provide here, I can't wait to see what you do here!

[mechanicalman]

Next step we removed the cab mount brackets planning on cutting down the middle between the 4 rivet holes that held them on. Here we punch then drill two 3/8 holes 24" apart 6" ahead of the front cut and 6" behind the rear cut. We cut the rear cut first to facilitate the harder to access front cut. That's my mentor laying out the lines and clamping on a guide for me to use the sawzall. I have to say the sawzall cuts well but very apt to drift if you try to go too fast. That was the last time we needed the 24" standard.

BTW (edit) we welded in a cross-support on the top but after we un-riveted the cross-member it sprang out on the bottom so we had to use a Model T one ton screw jack and a 2x4 to push it back out then we welded an additional cross support on the bottom of the frame rail before cutting.

[mechanicalman]

We used a BFH to pound the stiffener channels in (thicker metal than the frame rails) then the holes that were originally 24" apart became 12" apart so we bolted in the 12" standards to assure we shortened exactly 12". Our gaps needed to be ground down a little but in the end they were tight and the stiffener channels do a great job of keeping the frame rails straight but we did have to use a lot of grade 8 bolts to suck the stiffeners in all the way, and also bolts on top as well. We drilled through the front two cab bracket holes through the stiffener channel and installed those two bolts then drilled through the bracket itself to locate the rear cab bracket bolt holes. So the cab brackets bolted through the frame and through the stiffeners as well. And the rivet we had to remove from the front of the front bed mount became also a bolt that went through the bracket, frame, and stiffener channel.

We welded the butt ends of the frame together but my welder did not want to weld the stiffener plates in that area. We only stitch welded the stiffener plates on the edges of the C channels.

After we finished that the two left-over holes from the standard dimension worked perfect for the clips that hole the wiring harness to the rear.

[mechanicalman]

Everything else was routine stuff, shortened the brake line 12" and had to modify the fuel lines to fit next to the cross-member. New cab and core support mounts of course seeings how we had to raise the cab anyway and they were shot (only 43+ years old!). I already had poly bushings in the trailing arms and panhard bar so those were a quick in and out. Then I towed it home to do a transmission change and exhaust, parts are supposed to be here before the weekend and I hope to get it running.

Safety chained it but took this picture first.

A tow of this distance (12-15 miles) would cost me around 100+ so my $49.95 tow bar, towing lights, and wire jumper kit for the tow vehicle all come to about a one-way trip, I had to make two trips so the tow stuff paid for itself already and now I have it.

Yeah I'm gonna rattle-can the back of the cab for the time being.

[Andy4639]

I say you passed the challenge!

[mechanicalman]

Originally Posted by BruthaMan

Looking good! Subscribing. For all the great mechanical advice you provide here, I can't wait to see what you do here!

Thanks BruthaMan. I hatched the basic idea of how I wanted it done but my mentor in the picture conceived the one 24" standard, the two 12" standards to make it accurate and he did all the welding. At first I wanted to do a short Z cut, and he wanted to do a straight cut behind the cab mount bracket. We went home after the first night without a firm decision, and we both came back the next morning with the exact same plan to remove the cab mounts mainly because we knew the rivets would get in the way of the stiffeners plus we needed more stiffener in the back half for alignment. I was mainly a grunt, but he made it happen.

[mechanicalman]

Originally Posted by Andy4639

I say you passed the challenge!

Thanks for the kind words Andy. My mentor did most of the critical thinking, he's been down the road before but for me a first. Let's just say I did a lot of rivet cutting, hole drilling, and ran the sawzall.

I latch on to people smarter than me

[mechanicalman]

I forgot to take a picture of the jack we used to tweak the lower frame channel before installing the lower cross-support after we removed the rivets of the cross-member, but here is what one looks like just picture it in the frame channel with a 2x4 stacked atop it to go across. My mentor owns a Model T.

[cooperhw]

Looks pretty good to me.

[truckster]

I have a tow bar setup similar to yours for my Blazer. I used a piece of angle to go from one side to the other so I wouldn't accidentally tweak the front of the frame. I just measured the distance between the mounting bolts and drilled holes through the angle and ran the bolts through the angle.

[mechanicalman]

Originally Posted by truckster

I have a tow bar setup similar to yours for my Blazer. I used a piece of angle to go from one side to the other so I wouldn't accidentally tweak the front of the frame. I just measured the distance between the mounting bolts and drilled holes through the angle and ran the bolts through the angle.

In hindsight, I should have done that; I hope I'm able to get my bumper back on. I'm thinking a piece of angle iron that stays with the tow bar long enough for most frames.

I remember when cars still had bumpers we used to rent tow bars that clamped to the bumper itself; I haven't seen one lately.

"Unsafe at any speed" Ralph Nader