702 GMC V-12 powered '62 GMC 1-ton

[cayoterun]

Found some "no sellums, gonna' fixums" and some museum pieces in their annual "Santa Fe Trail" celebration.
1947 Spartan trailer house, a 1916 Dort Hearse, (so rare, value can't be determined, body all hand carved wood.) Some Conestoga wagons.
So much for our last ten days of "junkin" and celebrating.
Fuel cost hit $.50 per mi. on the '97 454 this week. We'll be tinkering in the shop for a while. Gas hit $4.00 @ 8mpg.

We were invited to bring "Balaur" to Adrian, Mo. and run it in the stand, to an antique truck and tractor show this month but turned down the chance due to fuel costs. Goodness, will it ever quit???
Cayoterun

[cayoterun]

I've been checking out the C50/60s straight axle chassis. Could have several advantages.

How do you find out the rear end ratios on two speed axles? For example, if one ratio is 4.10, would the other ratio be higher or lower? If higher, would sure help some on the low rpm/mph problem.

Also, could spring leaves be pulled, both front and back, and long rear shackles used to lower the truck some? It will never have more additional load than 1000-1500# in bed or hitch besides the additional engine weight in front. If the spring travel was reduced to say 2", would the springs still be stiff enough to keep it from "bottoming out" too often?

Since I've decided to stick with the '62 GMC pickup cab and front clip with motor in front, regardless of frame and running gear, the po of crewcab wanted it back, so the project has sure wandered away from the thread title.
Thanks,
Cayoterun

[jeffspower]

IIRC, most of the 2 spd. rears are around 6.60 high, 8.80 low ratios. Varies by brand, but I think most of GM T140 & T170 rears were these ratios. I've nver heard of any 2 spd rear that even gets close to the "fours".

[watahyahknow]

been looking into trannies , a allison 540 automatic might be the best one for the aplication , its a 4 speed vaccuum operated can hold up to 320 hp 1000ft pounds of torque and operates at a max of 4400 rpm there found in schoolbusses and light trucks there pretty common

[cayoterun]

I have a 5 speed direct tranny that fits the motor. Big hurdle.

Also have a 3spd auxillary tranny. Ratios: L=2:1 D=1:1 O=.85
If we turn the auxillary backwards, in aux. low, will that double our mph in each tranny gear? If so, we may be running 60mph in 4th gear @ say 1900rpm.

For the gear calculation, with a 4.10 rear end, would we use 2.05 rear end ratio to get correct speed in each main tranny gear?

Also, would the Aux still lubricate ok for the limited use and mileage this truck will be used?
I'll still have to have both drive shafts built to connect it all, regardless of which way the aux. sits.
Thanks,
Cayoterun

[89 crew]

Originally Posted by cayoterun

I have a 5 speed direct tranny that fits the motor. Big hurdle.

Also have a 3spd auxillary tranny. Ratios: L=2:1 D=1:1 O=.85
If we turn the auxillary backwards, in aux. low, will that double our mph in each tranny gear? If so, we may be running 60mph in 4th gear @ say 1900rpm.

For the gear calculation, with a 4.10 rear end, would we use 2.05 rear end ratio to get correct speed in each main tranny gear?

Also, would the Aux still lubricate ok for the limited use and mileage this truck will be used?
I'll still have to have both drive shafts built to connect it all, regardless of which way the aux. sits.
Thanks,
Cayoterun

In theory yes, by hooking the second transmission up backwards should give you the gears you want. Far as will it work, don't know, I have never tried it. I have seen depression era doodlebug tractors made from old cars and trucks. To get the gears low enough they sometimes hooked 2 transmissions up in line. Same idea just going the other way with the ratios. I can't think of anything that would stop it from lubing. The only concern I would have is the torque being too much for the second transmission.

[cayoterun]

Thanks, Crew.
The "Brownie" is from a Ford truck, (Spicer 5831D). On the 6066 guy's website is a good break down on these.
I agree the "brownie" could be the weak spot. Sure have to keep a soft throttle and clutch.
If my guessing is right by doubling the driveshaft rpm into the rearend, it should be the same as having 2.05 rearend gears. If I'm wrong, someone correct me.
By using those ratios in the computor calculator, it shows 62mph@1600rpm, 5th gear. That's great for the old motor. 93mph@2400, plenty and more that I want or need. Middle ranges fit ok too. If needed for slow speeds, drop the brownie in direct.
Maybe, we're gaining on the driveline deal, I hope.

Thanks to all for the help.
Cayoterun

[89 crew]

I looked up 6066 guy's site. The main concern I have is the fact the the gears are pulling backwards. They are not designed to handle stress in that direction of rotation. It may work great forever, or it may blow up immediately. personally I don't know. If you don't care, I would say, go for it and see if it works. In reality the absolute worst I would expect would be a break in the case allowing the gears to bypass. If it is a steel case then I would only expect a crack at the worst.

[89 crew]

I talked with my dad about this today, He used to be a transmission man for Gm dealership back in the late 50' early 60's. He said where the teeth are beveled on the back edge it won't work. He said with little to no stress, it will still grind the teeth off of the gears. If you find the same gearbox with straight teeth on both sides of the gears it will work.

[cayoterun]

Thanks for your trouble, and thank your dad. I have no idea how old the gear box is, so when we get closer to putting it in, I'll pull the top off and look. Your dad may be familiar with this specific gear box and knows what's in there.
Even if we run it like it's built, we can use the .85 over (high) and change ring gear and pinion.
I'll keep looking for a 5th over tranny in the mean time. I've still got a long ways to go. I need to use the KISS (keepitsimplestupid) method as much as I can.
I'm about ready to sit the motor in the frame, tho.
Thanks,
Cayoterun

[cayoterun]

We're never to old to learn. Never gave any thought to helical (beveled) gears, thrusts factors, etc. 'til this came up.

I pulled the top off this "brownie, and it has the helical gears and I can see where the thrust could create a problem.

Crew, would your dad, or anyone else, happen to remember approx. when they changed from the old straight gear design to the helical? I'll bet it was mid-50s or before.

There's a chance I might find one here in a farmers junkpile.

I'm getting anxious to start bolting some of this pile of parts together, but want to get motor and some kind of driveline in the frame before starting to cover it all up.
Thanks,
Cayoterun

[89 crew]

I asked for ya. He said they have both types of gears still today. The straight tooth gears are typically used on lower hp applications. Basically you are going to have to either know what you are shopping for, or open each one till you find it. He can't remember a model number of intermediate tranny with straight teeth (but he knows it was made).

[cayoterun]

I know of a couple around here, so will check them out.
If I don't find something in the next month or so, I may gamble on using this one. Probably never drive this thing other than short joy rides, parades, and on and off a trailer.

"Balaur" has been alot of fun so far. The old guys around here talk about them like they were a favorite old horse. When I tell them what I'm trying to do, they just light up and start offering parts, ideas, and support. They want to see one of the old brutes shown around.

Who said old wore out farmers can't have fun?

Thanks to you and your dad.
Cayoterun

[89 crew]

Not a problem, Let me know if I can dig up any more info for you.

[cayoterun]

Little by little. The motor just dropped frame to floor clearance to 22" and the frame stood 17" from floor when the truck was complete. I'm sure we'll need a lot bigger radiator than this one.
Maybe start on tranny/s and drive shafts tomorrow.
Cayoterun
Drained water in floor, (really forgot to tighten hose clamp)

Frame pic. was to show marks where cab would sit, then 9' flatbed from there back. They don't show up very well.

[Palf70Step]

Now we're getting somewhere.


It looks so cool sitting in there.

Oh yeah, my shop floor looks the same.....for the same reasons. you would think drain plugs would hollar at us ans remids us to go back in.

[62 C60]

Originally Posted by cayoterun

IMO I would cut holes in teh hood and run the zoomies.


Zoomies FTMFW!!

[cayoterun]

Probably no hood at all. As we all look at this and work on it, I'm trying to come up with a sensible, safe, and legal way to leave the motor as open and visible as we can. Front clip will probably be the last to go on. Give us time to look and think.
The zoomies would have to be muffled down if you were going to drive it. We have to have ear plugs to run it now. If anyone comes to hear it run, we always give them earmuffs to wear and stand away some 15-20 feet. Loud!! wow
Cayoterun

[MonteSS454]

Oklahoma state law requires atleast 6in of exhaust pipe past the cab and it has to run mufflers.

Done got into trouble for that one.....:P

[watahyahknow]

seems there's still room for a second radiator behind the first one maybe brace them together , or put a second radiator next to the frame under the bed with an electric fan

[cayoterun]

On page 6, post #139 by "Storm Chaser" is my favorite "look". That's straight from the 50's and my teen years. Those are the jalopys we put together, and was glad to have "wheels" of any kind.
I'll probably have this thing apart a dozen times. Just hope to have a road worthy vehicle, run cool (temp), fun to drive, ugly, but ol' "Balaur" standing out there tall and proud.
Thanks,
Cayoterun
in second childhood, and lots of fun.

[79Silv4x4]

Originally Posted by MonteSS454

Oklahoma state law requires atleast 6in of exhaust pipe past the cab and it has to run mufflers.

Done got into trouble for that one.....:P

Really? Where did you find that? Not doubting you--I just haven't seen much in the way of exhaust laws/regulations since OK did away with the yearly inspections. This info might come im handy!!! Thanks

[MonteSS454]

That's what about 5 different cops told me, I listened to the one that just gave me a warning.....:P

I've heard OK is bringing back some emissions laws that require cats too.

[msgross]

has anyone mentioned "over compensation" in this build yet?


looks like a fun project

[cayoterun]

First fit on cab. Will have to come off to make shift linkage and cab mounts.