The Stovebolt Site Forums The Shop Area Engine Shop 65 mph plus on a straight axle

Is there anyone out there with the original axle on their truck that can go at least 65 on the highway and it handle decent. At this time my 37 cant go that fast and before I change the trans and rear I would like to find out if thats not possible what can I do to it to make the frontend handle higher speeds. I have bought a tube shock kit and I am planning on removing some leaves from the springs but what else can be done?. I want to be able to get out of the slow lane with this truck without spending a ton of money if possible

The axle is fine if it's in good shape. Worry about the brakes they stink. Convert to disks or get the high friction shoes.

Jeff,

My truck's drivetrain is original EVERYTHING (engine, trans, rear end, brakes) and I've been on the interstate at 65 mph for over 100 miles. I've done several 50+ mile each way trips on the interstate at 65. No problems whatsoever.

The truck is a 1966 1/2 ton stepside. Original 230, 3 speed column, 3.73 rear end. The 230 has a short stroke and 7 main bearings so turning 3k continuously is no big deal.

Since my truck's a 1966, with a later drivetrain it's not exactly a "stovebolt". So my experience may be meaningless to you.

-ftyler

I've been up to 65 in mine (216 was on its way out anyway ), it still handles fine (I have radial tires), but you need to be careful about hard braking making it squirrly. I am going to put a swaybar on it and eventually disc brakes. My front suspension has been completely gone over, though, with new shocks, bushings, wheel bearings, shackles, king pins, and adjusted steering box. I wouldn't drive it on the highway without that. I like to not hit things.

Make a mount for a steering stabilizer and use radial tires. Make sure the bearings and king-pins are in good shape and the allignment is true.
Brakes are something to reckon with if they are stock

my 52 does fine on the interstate at 65 more, it
still has the stock susp,and brakes, I just try to
be more alert when I drive it, I feel that it is a good truck, everything is in good shape, but it still is a 51 yr old truck. all ways remember that..thanks, Fred

I have radials on it but it still handles bad,every part on the front is probably original but checked good when I redone the truck. I will have to do something about it when I get the o/d trans and modern rear in it,I dont want to be all over the road at 65. If I keep the axle I will definately change the brakes,it still has the original 37 style on it,I have a complete set from a 51-up to put on it if I stay six lugs or will go to 53-4 car If I go to five lug. I am used to mid to late fifties oldsmobiles that will cruise 85 all day and handle good,I think I am expecting this truck to do what it was not designed to do. If I had to do it over again it would be made into a streetrod,I see them going down the highway with no problems. I appriciate any insight on this delema,I have to get another project finished before I tear it down for improvements but would like to have made up my mind on what to do to it before it comes apart> Jeff

Jeff,

In the twenty years that I drove my '49 half-ton with a straight axle, the biggest single thing I did to make it handle better was to add a front anti-roll bar set-up from a similar year panel. I also ran Camaro disk brakes and a '69 Impala rearend with 15x7 rims (S-10) and P235/70SR15 tires.

I put about 20,000 miles on the truck, driving all over the Northwest and never felt uncomfortable with it's handling. Once I got a 350 V-8 in it and the disk brakes on the front, I never had any problems with it going or whoa'ing either.

Prior to the anti-roll bar though, it was plenty 'twitchy' and would keep me on my toes out on the road.

one of my friends has a hot rod model a with a dropped straight axle, f-1 drum brakes, bias ply tires, early sbc, th350, open rear, etc, and we've gone 100mph+ no problem (except for aerodynamics!). he drives the car daily in the summer (no heater). granted, it drive like a honda civic.. you've just gotta pay a little bit more attention to where your vehicle wants to go.

you'll be fine doing sixty-five so long as you make sure everything's in good working order. later brakes are nice too. if you're not hardcore about the nostaglia thing, you could easily add disc brakes and radial tires.

ed

My 37 drives fine at 65 or faster. It has a 250 with a 3.42 rear axle. I converted to disc on the straight axle and late model Firebird rear axle. I just installed new front springs which help a lot. The streering is all rebuilt and king pins are original. I run 205/75R15 radials on the front. Check your alignment, mine was all over till I reset the toe in. Joe

When it comes apart for the trans and rearend improvement, I think the front is going to recieve new king pins and modern tie rod ends. How does the balls on the old style tie rod ends come off the spindles? or does later spindles need to be found. Is there a newer steering box from a fities or other truck that can be bolted in for better steering feel. I would like to lower this truck a little,I have a catalog from a local rod parts store and to buy a dropped axle, get spindles from a junkyard,find a good vega box or a new one,buy the box adapter and draglink parts, maybe new springs,disc brake adapter kit and rotors and calipers,hoses etc it would be cheaper to buy a mustang 2 hub to hub kit, but at this time I dont have the money to do either. If there is anyone who has a dropped axle with disc brakes on their 37 of 38 and is going to install a independent frontend let me know I will buy your old parts. Jeff

Try this,
Mono-leaf springs, good for 2"-3" drop
complete disc brake kit,
rebiuld your steering joints,
replace kingpins if they are loose,
update to 40's truck steering box.

With all the above, the only adapting is the steering box.

With the M-2 front end, you be like every other aftermarket rebuilt truck on the road! Joe

Joe H that sounds like a plan,I might get the kit to install a vega box and go to cross steer instead of a 40s box. Who makes a swaybar for thoses older trucks?. I know the m2 would be like alot of other trucks but it would ride like a car but the cost is too much for now. I found alot of parts in the garage for vehicles I dont own anymore,if I get them sold there is some money for the frontend improvement. Jeff

I kept the straight axle on my 46 and it is fine on the interstate. It will run 70 to 85 all day. I put mono leafs on for the drop, tube shocks, rebuilt the king pins and tie rod ends, 15” radials and added disk breaks for some Whoa.

jeff-

rb's obsolete sells a kit to adapt the vega box to your truck, but it's very $$$. i may switch over to the vega box on my '31, as it's supposed to have much less bump-steer than the side-steer. if i make the switch, i plan to buy the vega box off ebay, fab my mounting bracket, and get all the steering rods from speedway.

if you're looking for a drop axle, MAS and RB's both offer tube axles with up to 6" of drop (remember that your stock axle probably has about 2" of drop). the axles use 42-28 f**d or 49-54 chev car spindles. 5 and 6 lug disc brake kits are available for both, as well as all the steering arms, etc that you'd need to mate it to the vega box.

ed

It depends on the highway. Yes 65 is possible on a flat 4 lane but I drove my GMC on the W. Va turnpike and got the S**T scared out of me when the brakes faded and I was caught in a downhill group of 18 wheelers, no mercy there, sheer terror. I finally took a runaway ramp and just sat there shaking for about 30 minutes. A straight axle, drum brake, leaf spring front end has no business in these conditions, even with good weather and radial tires. My truck was a hazard to me and everyone else on the road. I became an instant convert to IFS on that trip.

My 37 pick up has the original beam axle,disc brakes, monoleaf springs,lowered about 2 inches,4 degrees of castor, tube shocks and a 41-46 recuriculating ball truck steering box, the box is a bolt in.The 3.36 gears limit high speeds for the long run, but it's gone 75 MPH for a distance and the truck tracks very straight .The biggest concern is the stock rear suspension design that allows more oversteer than a modern truck.So you have to be careful.Look at the back leaf suspension of a PU truck made in the last 20 years.The rear shackle is around 5 inches higher that the spring eye at the front of the rear spring, unlike older trucks. This design tends to make the rear end feel planted more firmly in turns and emergency manuvers. A front sway bar will lessen front tire grip , adding some stability in high speed turns. Every old truck I ever drove tended to steer with the [censored] end when pushed through a turn, you get sideways ,your truck is going to flip over. The main concern here is even though lowered some, the center of gravity is still sort of high, drive with added caution at high speeds. Remember, Jeep Grand Cherokees have solid front axles as do 3/4 ton Dodge trucks, they handle no better or worse on smooth roads than similar vehicles. For the most part most old trucks have suspect suspension parts and worn or stiff steering boxes,fix it properly before condeming the straight axle design.The Vega box is a Saginaw recurcilating ball box, identical in design to the any GM Saginaw box from 41 on up.A old box in good condition will steer just as well in my opinion.

Yes I did swap out the rear spring shackles for a set of front shackles.

Thanks for the info,My plan now is a dropped axle,mono leafs,tube shocks,41-6 box,disc brakes and new kingpins and tierod ends. On the 41-6 boxes does it matter what size of truck it came off of. A local junkyard has a few big trucks that the doors have been closed and have all the windows and the hoods been closed,the only 1/2 ton had no windows no hood and no steering wheel so the box has probably gotten water in it and is junk. Who sells sway bars,I would like to put them on the front and back. Jeff

Hey Sixpack:

What kind of front end and brakes did the 18 wheelers have?

Mustang II ? LOL

Tony, yeh the 18-wheelers have leaf spring straight axles. They also have brakes that work (most of the time) and drivers that are used to 75 mph in the mountains!

Our brakes can be made to work very well. Look at the size of the drums and shoes. Pretty big. 50 year old brakes are bad, but the design is good and if all new and the parts are working properly it will stop these trucks pretty good. Unless you want to do a lot of mountain towing. You should always however drive within the vehicle's limits. These will never be modern, nimble lane changers. These are trucks that belong in the slow lane. With some driveline modifications maybe at 65mph.
IMO