Holy crap!! This monster DT is incredible! The craftsmanship and excessive knowledge that went into this build blow my mind! Cant wait to see this finished! Klaus
Appreciate the double check and yes I do plan to measure again before cutting as I've made an assumption on the track width. Tell ya what, if you can measure the distance from the wheel mounting face to the outside of the frame on yours then I could verify my numbers. However, I run different offset rims than you do, mine are 6.44" inset (Accuride 27403) which means the hub flange is the most outside part of the wheel. Have a look at a semi truck and you'll see what I mean. BTW dump trucks have a smaller inset in front, that's what I am using in the rear of this truck. And my 211 cab/fenders are physically smaller than the 509/614 units. The cab is a few inches narrower. I wouldn't be surprised if they are that much different. Shameless plug, if anyone is interested in a complete set of Diamond-T 211 sheetmetal let me know. I have a full cab, fenders, hood, nose available.
Saw this one in a huge truck collection last weekend... They were packed so tight I couldn't get the best pics.
How's come they're ALWAYS red? That's what mines gonna look like, albiet (a lot) lower and with chrome bumpers. (not meaning to hijack your thread Scotty, it's just too much like my truck to not comment!) Brian
DT's were only offered in red with a green trim stripe. Generally there was white pin striping outlines around the upper portion of the cab. And that's why mine's gonna be blue...
Are you sure? The left front fender on mine was black laquer under the red enamel repaint from 40 or so years ago, and NO other paint or bodywork was evident on it. The rest of the truck was ALL red, although the frame rails were black. Brian Oh, just found out my headlight rings and hood ornament are DONE at the chromers! Yee-Hawww! Only thing I'm missing now are hood trims (I want stainless) and I'm thinking of making stainless running board trim, as opposed to the stock black rubber rub strips.
Picked up a set of air ride parts from a local guy yesterday who decided not to go this route on his truck. Feeling like a kid at Christmas, lots of new toys. RE-7 air bags (2x) Conti 2800 air bags (2x) 5-gal 6-port tank Bracket setup for 73-87 Chevy front suspension upper and lower plates 36" 4-bar link (2x) side frame 4-link mount (2x) Brackets for rear axle 4-link Shock brackets Should be enough here to get the front suspension converted over to air once it's in. Still need some parts to 4-link the rear, and I'm looking for a bit more bag travel and capacity in the rear than the Conti 2800's would provide.
Picked up the IFS setup this morning. looks just about right for this application. Better yet, the frame rails are the right width and angle for it. Heck, it might even bolt right in- only question is where the wheel centers will end up. The 1-ton dually has the extended nose rotors, just laying out with a tape measure it looks like it will increase the front track by about 2". If it is really a problem I can get a pair of corners from a SRW truck which don't have the extended nose on the brake rotor. Got the steering box as well; Seems like it's the same unit as a half ton truck which is a little disappointing.
Wow! How the hell did I miss this one? You can NOT go wrong with a Diamond T in the first place, and it sounds like you've got a solid plan going on. Can't wait to see the outcome!
Richard- Nice pic. Looks a lot like that late 40's big DT cab was dropped on a Chevy 1-Ton frame by the width of the wheels and the bolt pattern up front.
Fresh chrome- fantastic! I'm not there yet. Need to go muggy weld the pits then get a plater lined up. If you don't want your old trim lemme know, I'm interested to purchase. For the running boards I'm undecided. Might go with painted strips using bedliner but making the strips out of brushed stainless would be a good idea.
Short answer is No, it is close to the right size. There are some things to point out now that I have the toys in front of me- certainly there is no widening needed. It may even bolt right up to the frame. Exhaust is going to be interesting though. The 1-ton that I got the front clip off has a different brake rotor than your G20 has- with an extension cast into the brake so that you can use the same rear dually offset rims on the front. With the stock Chevy dually offset rims the track width is within an inch or so of being right on the 614. I'm assuming your G20 has brake rotors without the extension. Your truck is smaller in width, also you are using different offset rims than I am. (Hmm, if they fit over the brake calipers you could have saved some fab work to use the 1-ton offset rims with your non-extended rotors!) This is likely the direction that I will go to put a set of adapters on without widening the front track from what it is now. Think I still want to run the Alcoa 22.5x7.5 rims with 6.7" offset up front but now that the brain is working the non-dually brake rotors might be well suited to the adapters and another set of 893630's like what is in the rear. Hmmm, need to get on the workstation and figure out the cross section.
Yard trip! Half price day, of course they don't apply that to semi-truck stuff so I guess that it was just a regular day foe me after all... Got a nice assortment of push lock connectors, all DOT stuff. Straights, Tees, 3/8-1/4 adapters. Pair of supply pressure gages, some electrical switches from a Pete, pneumatic switches, solenoid and a ride height actuator. Worth the trip. Found a dash-mounted filter restriction gage too.
Well, I'm measuring up the front axle and finding that yes, it's too wide. ~74" between wheel flanges. Luckily for me that means that I can change from the 1-ton dually front brakes (with rotor-integral extensions) to the SRW brake rotors which are not as wide. According to the brake rotor guide, I should be able to shave 5" off the track width, bringing it down to ~69" OAW. With the adapters adding 1" that brings me to ~71" OAW. Given that the original Clark axle measures out at 73" between flanges, it looks like this C30 subframe is a bolt on with the right width adapters (2"). Might wait til the front suspension is bolted up and at ride height before ordering so that the width is spot on for tire clearance.
The OBA (on board air) project is starting, been looking over the shoulders of the off road guys and picked myself up a York compressor at the yard this weekend. $46, more than I had planned but if it all works out great. The belt interface is another issue. Serp belts are difficult to come by, supposedly 79-83 mustangs with the 5.0 option but like unicorns very few people have actually seen them. Big trucks use them, luckily there's an off the shelf item for this application: http://www.ryderfleetproducts.com/cgi-bin/ryderfp/products/srm/oid/47299/erm/product_detail.jsp As well as the home-grown version: http://www.madxj.com/MADXJ/technical/technicalfiles/ARyorkPulley/YorkPulley.htm
Got to make some progress. Removed the front beam axle then started measuring. The front springs are actually pretty difficult to remove, the rubber bushings are in good condition and staying put. Truck looks interesting floating in space...
Made a template for the front IFS unit. The CAD work says it all fits. Just wanted to check before drilling and bolting.... Quick unit out of sheetmetal to verify the width and angle of the pads, uses a crossbar attached with clecos to also allow for use as individual side drilling templates. Overall the interface between the frame and IFS looks good, the only change is that the frame is curved on the bottom and needs to be extended down to meet the IFS subframe. Nice touch is that the original wheel centerline hole can be used for ensuring the IFS subframe is bolted up in alignment with the centerline of the vehicle and is even on both sides. Handy. I've marked the subframe CL on the templates, makes it all easy to transfer locations across and preserve location dimensions. I'll probably need some slight shims both sides between the subframe and the outside of the truck frame rails to keep the wheel centers in location.
Front springs cut out. Tried pulling the bolts on the shackles but got frustrated and just decided to cut to the chase. They are quite heavy, I'm glad to have them off and removing the brackets from the frame should be easier now. First look at the IFS under the front of the truck shows that I actually need to widen the subframe. Wheel centers end up being about 3" too far forward. Two steps forward, one back.
Cut the subframe and widened .630". Tacked back together with leftover scrap so that it could be test fitted back in the truck. Might be a little much, I'm going to bring it down to .500" and see how that fits. Aiming for a thin shim on each side, so if it pulls too much on welding I'll be able to get it to fit in the center of the wheel well.
Interesting. Your crossmember had to be widened half an inch, while mine had to be narrowed 3" to fit the 201 frame! I was able to use the original front fender brackets by trimming them down, leaving just the back where the mount holes are, and added a piece of angle iron which now bolts to the top of the frame rail. They interfere with the crossmember.
Brian- If I knew, I'd have asked you to save the 3" section to use to fill mine! I'm curious as to how yours all mounted up, perhaps you can post some more pics of the steering box and idler arm mounting? The IFS subframe is .150" thick material, and if I hadn't run out of cutoff wheels today I'd have the patches cut to fit and welded in place. Nothing is open on turkey day of course, being the last real holiday left. Cut the subframe gap down from .630" to .500; then opened up to .580" as a final fit. Checked the wheel centers to the fender openings as well as the bolt up points to the frame which have been aligned to the factory center hole. Only interesting thing was a notch for the exhaust. Cut out a section then flipped it in place. Was a bit worried about this but it turned out well, just needing a small bit of clearance.
Be aware that changing the width of the crossmember without also changing the steering cross link will have bump steer ramifications. In the vein of steering, how you are going to adapt the "fore-aft" box that came with the truck to the "starboard-port" arrangement that the donor crossmember has? If you don't have anything in mind yet, I would like to make a suggestion. If the stock pitman arm points down and is vertical with the box centered, then you could use a short drag link forward to a bell crank hung and pivoted under the driver side frame rail. You could place the bell crank such that it was located in the same place and operated in the same fashion as the donor's steering box and pitman arm, which would maintain the donor crossmember's four bar steering geometry. That would be a very slick looking install, if properly executed, and the one I'd lean toward. Alternately, you could instead connect the other end of the bell crank to a second drag link that would pick up the donor center link somewhere in the middle (via a new tab you'd have to attach). You'd use another idler link on the driver side of the donor center link (where the donor's pitman arm and steering box would have been) to maintain the proper four bar geometry. If you set down and do the math beforehand, you can also correct the steering speed when you build the bell crank (nothing says it has to be a 1:1 bell crank). That can be done no matter which way you decide to actuate the donor center link. You'll also need to shorten the center link the same amount that you narrowed the crossmember, again, to maintain the four bar geometry. Take that material out of the section between the tie rod pickups, right in the middle. If you maintain the bar angles, the steering won't care how far apart the tie rod pickups actually are. If you don't maintain the stock angles, the bumpsteer will go full batshit toward the ends of the steering travel. Anyway, it's an awesome build, glad to see you making continued progress.
I don't understand what you're talking about with using a bellcrank? As far as the center link/bump steer issue, that shouldn't change as long as the center link is narrowed (or widened,as the case may be) the same amount as the crossmember would it?. The pivot point of the tie rod will still be in the same relation to the suspension arms as it was originally. I just heated up the mount for the idler link to mount it to the frame to allow it to hang in the same plane as the pitman arm, if that makes sense. It should, I would think, be all the same as GM intended. These pics are of the steering in the "mock up" stage, but the box and idler link, center link, are in (roughly) the same location now that it's all done. The mounts for the box are heavily gusseted, and I boxed the frame rail forward of the crossmember where the box mounts, and tied it to the crossmember as well. Brian
You used the steering box from the donor vehicle. I assumed he would be reusing the box that came on the Diamond T. Since the T box was a fore-aft working push-pull type that just had a drag link running forward to a steering arm on the driver side spindle, he'd need the bell crank to change the fore-aft motion into starboard-port motion. If you change out the steering box, then most everything I said isn't needed. And yes, if you narrow the center steering link between the tie rod pickups the same amount that you narrowed the crossmember, you maintain the four bar angles and thus should pretty much maintain the bump steer characteristics of the donor assembly. In fact, I said exactly this in my previous post, you probably just missed it. That post got a little long winded. I just assumed he'd be keeping the stock T box and steering column to save the work of retrofitting something newer.
Part of the reason to go to this IFS setup is to also gain power steering, I'm planning to fit the C30 PS box. I'd been looking for a Garrisson unit for a while which would fit in the link between the pitman arm and the corner, haven't found anything in 2 years of looking. Don't really want to have 50 year old hydraulics either. The C30 box is cheap, common and usually works. Tie bar length: yes, it affects the bump steer. And it also changes the Ackerman angle. I need to lengthen mine .580" to make the geometry go back to design.
Ahhhh, now I understand why you thought a bellcrank would be needed. I too figured PS was a MUST do. Actually, mounting the box was the easiest thing I've done! Figureing out the wiring, not so much...
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