The Stovebolt Site Forums The Shop Area The HiPo Shop AD Cab,Modern Chassis,V-8 engine,What about my Steering???

Hey there,
I am getting ready to start working on a project and what I am starting with is a 51 GMC,Cab and Fenders Onlyoff a Big Bolt truck.Everything is in excellent condition,it was off a fire truck.I DO Not Have the Chassis.The cab and fenders were separated from the chassis and fire equipment,I don't know the circumstances as to why.

I want to build a truck to use for construction work that will be used daily as a working truck.It will be used to haul around tools,equipment,some materials and to pull a trailer.I have a late model Chevy that does the same thing,that rolls down the road weighing 11,000 pounds.The AD truck will be similarly equipped with a service body with tool bins.The AD truck will be a 2wd dually,and the service body will be about 11 to 12 feet long.

So,I need a truck chassis to mount the AD cab and fenders on.I understand very well that a late model chassis is much wider than a AD chassis.

I know I will be going with this so far:
'51 GMC big Bolt cab and fenders
V-8 engine,probably a 6.0 LS engine
Late model chassis,disc brakes,etc.
Probably a 4L80 automatic
Dually rear end
A modified Service Body with vintage styling

OK,with that out of the way,I know I have to deal with a steering column/linkage issue.I need a bullet proof,reliable way to wheel this heavy truck around everyday.I know running the V-8 6.0 Vortec engine and inboard steering box,I can't see the steering shaft clearing the engine.

Any tips on this?

There are plenty of ways to get the steering to clear the engine. On my '46 have an S-10 frame (relatively narrow) with the steering box on the inside of the frame, with a 455 Buick, and I had no problems clearing the engine for the steering. It's close, but it does clear easily. If you are having issues with it clearing there are other options, like universal joints with a steady mount to the frame, or changing to a rack, etc. This is something you can easily deal with when you get to that point.

Not having a frame, steering gear box, or really anything in hand it's real hard to offer a solution to the problem that isn't yet defined. Other than it can likely be solved when you get to it.

Grigg

I just want to plan a little bit,if I can,and not trap myself as much as possible.

If you can give me the possible solutions if I do have a clearance problem,that would be great.

Some possibilities,just guesses on my part,might be,
Do guys cheat the column over a little?
Do guys cheat the cab over a little?
Do guys cheat the motor mounts over a little?
How close is close,and what would be normal?
How good would the extra steering u-joints work in a heavy-duty application?
And is a steering rack even an option here?

I just want to be mindful of things during the build and maybe avoid a certain problem before it is one.Hey,it might even effect the choice of chassis I make.

I don't know how wide a cab off a "51 GMC big bolt truck" is but, find a chassis with steering still in tact that had a V8 in it. Chevy, GMC, Dodge, Ford, whatever. Plenty of options, but you have to start measuring various platforms for width and what I said above. Isn't it an option to find a chassis from that era and update it? Borgeson makes steering components to do what you want (go around an engine) and they have the design parameters on their web site. As has been pointed out, you will not be able to just imagine how to do it. You have to find the parts by careful measuring and then still have to mock it up and then design the steering and all the other stuff after you have the basics. Unless you find someone who has done exactly what you want to do. Steering design is not your biggest concern. I'm just repeating what Grigg/46GMC are trying to tell you. Now you have two engineers and a machinist with experience building various trucks chiming in.

MrJuanderful,

The Chevy 70s-80s fullsize truck frames will have the steering on the outside. (Borgeson!) Placement of the engine to the radiator can be an issue and crossmembers, brake master will need to be considered.

We used a shortbed Chevy truck frame for the wheelbase, it's 1 inch longer and 4x4 was the direction we wanted. It's the width that may cause you a problem, I've read that the fenders off a Bigbolt are wider, so that might help.
& a Mechanical Engineer chiming in..
good luck on your project.

You can cheat the column over if it works for your dash and seating, the steering box doesn't care. You can cheat the cab over if that works for wheel wells, trans, bumpers and all kinds of other problems. You can cheat the motor over a little, driveshaft can be a little crooked, but the tranny shifter, exhaust, fan and etc. will have to be considered. How close is too close depends on what you are talking about specifically. The above cheater items are not recommended, you can get yourself in a catch 22 situation before you know it. Much, much less trouble keeping EVERYTHING symmetrical. Borgeson will answer your heavy duty questions, If you have power steering, there is no "heavy duty" stress on the steering Ujoints.

The 73 to 87 chevy or gmc is what i used for my truck. Its a ton truck with a 9 foot flat bed. You sound as if you are looking at about the same type of truck except with a utility bed instead. Check out the photos in my signature. If you will notice my truck is a ton truck which had the smaller fenders. Your fenders have a bigger wheel opening. I used my original steering column and two u-joints to connect to the 78 model gear box. I have a 454 that wasnt a problem to work around. Dont get me wrong it is a tight fit but still not a big deal. Spend some time in the gallery looking at the photos, there are a few conversions like this in there. May be difficult to find but they are there.

I want to thank everyone for their input.It seems like the steering clearance issue can be taken care of when that bridge is crossed,most likely with an extra shaft and u-joints.I just wanted to be sure that solution produced zero slop in the steering performance and seat of the pants driving feel.

One reason for me wanting to do some extra planning and preparation,is that I want to media blast and paint every component on the truck,including frame.I'm going to set the cab on a rotisserie soon and get to work on patch panels,floor repair,cab modifications,etc and get everything to a point where I can send it out to the media blaster,get it back and epoxy prime it.Once I swap the cab over to the modern chassis,I need to make it a roller as quick as possible,I just don't have the room or facilities to leave it apart for a long length of time.

DSmith,great looking truck.Especially happy to see it out in the field on the job and getting things done.Yes,your project is the type that I need to be looking at.

If anyone can guide me toward info and pictures of Advance Design truck on modern chassis,please let me know.

Are you keeping the stock column, or replacing with a tilt column?

I agree with stock column you may have issues. then again, you can always cut the column down, run a few steering u-joints.