The Stovebolt Site Forums The Parking Lot Tons 'o Fun Higher gears and safer brakes for the 1 ton

I am happy driving 45 mph, but I'm interested to know how others have achieved higher speeds safely. I know about the elusive 4.11 swap(please explain details for others), but what other heavy duty axle/brake alternatives have been used.

I haven't done it yet but I'm going to put an over drive unit in my truck, the redneck way, but it should look and work good. I bought a 4speed tranny out of a 1950's 2 ton international truck. IT has very similar gear ratios to my 47 chevy. What I decided to do involves putting the tranny in backwards behind the original. I'm going to take off my middle mount and install it between the two drive shaft pieces that I'll have to have shortened.
I'm going to linkage the shift from it up to the cab through the starter button hole (my engine was up graded to a newer electrically activated solenoid) and have it so I can shift it between 3rd and 4th gear.
4th gear will give me my standard speed and 3rd gear will give me a .59 over drive, cruising 55mph at close to 1900rpm.

Hmm. I can't tell you how I've DONE it because I haven't finished yet...

But since all the big parts are inside the same shop I can tell you my plan. I want to be able to pull a 10,000 pound load across Wyoming where the speed limit is 75 and there are lots of hills to go up and down. I want it to drive easy and comfortable, meaning power steering and more than adequate brakes.

The rear axle has 3.42 gears, which is the key to higher speed for mine. I estimate about 2800 RPM at 75 with 265/75-16's. My motor is a Cadillac 500 and the transmission is a TH400. 2800 is near the top of the torque band for the 500 and I think gives me more then enough pulling power for up to 10,000 pounds hooked to the hitch.

As for brakes, it took me a while to settle on the right plan for that part. The rear axle is a GM 14-bolt (with 3.42 gears) and it has large drum brakes. I've measured them but have forgotten the size. I've considered swapping to disks brakes since they are available for this axle, and may end up doing so before I'm done. The rear brakes were the easy part.

For the front I'm using a '72 Chevy C20 IFS complete with disks and power steering. This is the same stuff Chevy put under a single wheel 1-ton and my particular setup came from a big block truck. I spent a lot of time considering disk brakes on the original axle, but after looking at several trucks with the same IFS and talking to the owners I concluded this was the best route for me.

Today the big parts are scattered around three stalls. The bare frame has the rear axle and suspension in place, and most the un-needed stuff removed from the front. The motor is on the floor ten feet in front of the truck, and the IFS is on blocks in another stall with the cab in between.

I'm only managing 8 to 10 hours a month on the project so it may be some years before I get to drive it... Aside from basic maintance on my other stuff this is the only project I'm actually working on these days. Pictures and more details are on my web site at Maxwell Garage Service Truck.

I swapped axles in my 1 ton, a Dana 70HD for the rear, and special wheels to make it fit. Then narrowed an axle for the front. Disc brakes front and rear, and gear choices as fast as 3.54.
http://rides.webshots.com/album/484062061lhMQfr

These axles are now under my 2 ton, which is a better fit, and was the plan from the beginning.

Grigg

I got tired of looking the much rumored but never found 4.11 pumpkin to fit my 41 1 ton rear end.

All my problems went away for $1,800.00. I got an all new rear end, 12 bolt, 6 lug, 2 1/2" wide brake 12 " in dia and 3.73 gears on a narrowed rear axel.

With a SB 350 and 700R4 transmission riding on original 17" rims I expect 70 mph at 2000 rpm.

I swapped out my 5.12 gears in the back with a 3.90 from Patricks in Arizona. I've still got a granny gear in 1st. It drives about like the International Scout I had a few years ago. With 17 inch wheels in the back I can do about 75 on the highway. I've got the original brakes and they work fine. At highway speeds the scariest part is the loose steering.

OK guys throw a rookie a bone here, please! This thread is somewhat helpful, but I really want to know what's going on.

Let's start with what I KNOW: rear is original-5.14 gears, # on the diff is 3882128, 10 bolt rear cover, front diff dump-open u-joint, full floater (typical info from resto pack). I want to stay with 8-lug, preferably the original rear, mostly because brakes hate me and I hate them.

What I want to know: Is this an Eaton (pretty sure)? What specific name do they call it (10 bolt 7.5, 8.5, 8.875, none of these??)? I thought Patricks had the closed tube rear for 3100's ..according to 47thrift that gear can be used in our rear? If not where can a 3.XX gear be bought? I have to think that a different rear (like a Dana) would probably be cheaper than changing gears, but then how much of a struggle will I have with brakes?

This is the first and in my mind most important thing to do for making this a reasonable truck to drive. Sorry for so many questions, but every search I do winds up confusing me even more?

If you run across some 3.xx let me know (without changing the axle). We did an extensive search and found out there was a production run some years back but none for sale. This is something I would really like to update in my truck.

Yes.

Eaton HO72. Eaton HO50 is the 3/4-ton. Primary difference is brakes, though the HO50 is usually 4.57 gears.

I've heard the talk, but never seen proof one exists. The 4.11 is rare but does exist.

Swapping to 4.11 would likley be your cheapest option. Getting to 3.xx I agree an axle swap would be cheapest and perhaps only option.

Choose a drum brake axle from a similar rated truck and if the brakes on the replacement are any good, then just hook them up and bleed them and go....

Dana 70HD is pretty common and has brakes about the right size. Some of them will be far too wide. GM 14-bolt is also common under similar rated trucks (I think often the heavier rated are Dana's, but I con't know that with certainty). Unless you're putting disks up front I'd stay drums in the rear. You'll have an easier time getting it to work right.

I've got a GM 14-bolt with 3.42 gears under my 1-ton and there is a 3.21 available with lots of options the other direction too. I don't think the Dana options are quite as highway friendly which is consistent with the applications of the two axles.

What year is your truck, and what motor do you plan to run? My 14-bolt came to me under a '49 1-ton with a 216. The guy I got it from said the tired 216 would hardly move the truck with the 3.42 gears and that was why he had parked it and eventually sold it.

You're the man OldSub! This is a '48. I have a lightened, balanced, long-rod 350 from my previous life as a dirt racer that'll get dumped in it, so RPM is not a huge issue...just don't see the need to run over 3500rpm down the highway constantly.

I do have a 4.11 rear out of a '68 Ferd 250 that might be close to the same width when measuring to the outside of the drums. I only measured the inside and it is about 57" compared to the ~53"ish inside on the OEM rear....but then when you factor in those HUGE brakes it may be closer. I'll have to remeasure on the outside. I can always couple a 4.11 to an OD and come out pretty decent. I have several 3-speeds, but if I can use what I have for the rear, that opens up some $ to use on a manual OD tranny.

Thanks for the help guys, I've been pulling what's left of my hair out trying to figure this thing out!

I gave up looking for a decent rear end and brakes for my 1941 1 Ton P/U and bit the $1,800.00 bullet for the perfect rear end and had a really good local guy build a 12 bolt rear end with 12" 2 1/2" wide brakes on a 3.73 pumpkin. All pushed by a stock SB 350 and 700R4.

All my frustrations went away and if it ever fails parts will be easy to get.