Parts is Parts

[amunderdog]

Class 7 and 8 types:
So my L series truck is lacking in a couple of areas.
So i have some old trucks out in the field.
I go out and look at the rear end under a 70's model International.
Who made the Rear end under the IH?
Looks Rockwell but the numbers are weird and it has IH stamped on it.

Second question why would they run a 5.30 ratio rear end behind an old 3 speed Allison auto trans?
Seems low for an auto trans.

Thanks.

[Kaliburz]

What parts are you planning to use on the L from the IH?

The 5.30:1 ratio would all depend on the auto tranny. I know that the old Blue Bird buses at work w/ the 3208 Cat have axle ratio's in the 5:30's. I suppose it's for get up and go.

[LMJD]

I go out and look at the rear end under a 70's model International.
Who made the Rear end under the IH?
Looks Rockwell but the numbers are weird and it has IH stamped on it.

When it comes to heavy trucks, they could be speced out with whatever rear ends/trans the buyer wanted so you'd have to get some numbers off it. One of the most common tandem differentials are Rockwell SQHD's. It's common for International to stamp IH on housings regardless if it's an Eaton, Rockwell, Spicer or whatever. They're the only ones I know of that in their infinite wisdom years back, insisted on painting Cummins, Detroit Diesel, etc, engines red rather than the factory engine mfgr. colors.

[amunderdog]

Ok
Just seemed to me odd.
Here are the numbers found on diff
It is a single drive axle application.
This one is a single speed.
161018-R2
D1
5.72
Truck 2 (does not look like a candidate for this need)
This one is even odder 2spd air activated 43246. No other markings but patent info.
I would like to keep my hub piloted hubs
But would use the whole rear as is if i have to.

My truck lacks the pulling power needed on the low side.
It has an 8.3 Cummins
And 6spd trans Eaton Fuller 6406A = 1st 7.05 Rev 6.75
The single axle under it now is a 21,000# Rockwell 4.10 ratio

I think i am going to end up buying a better transmission.
Am looking at RTO 11909 ALL has a 26.08 low gear
Or RTO 11908LL has 14.56 low gear.

I have a rebuilt spicer-model-6041-4-speed-auxiliary-transmission laying out here i could use. but the weight and difficulty to install does not bring it to the top of my may fix problem list.
The 6406A trans weighs 365# with the 6041 Aux would be around 7 or 800# by the time you got it all installed.
The other transmissions weigh 670# 11spd and 690# 8spd

Sorry for the long ramble...
But i need this truck working (very heavy / very slow / over very difficult terrain / would still like to get down the road occasionally at 65 to 70 MPH though) for the least moneys i can.

[amunderdog]

Here is a picture of the problem truck
And yes it has 24.5" rear tires and 22.5" fronts it came that way. I do not at this time have any Hub piloted 22.5" rims and drive tires to try on it.
Bet that would help some.

[LMJD]

Sorry, I can't help with any numbers as I have no parts books for reference.

This one is even odder 2spd air activated 43246.

The majority of 2 speeds, air or electric shift were by far made by Eaton. I've overhauled a gazillion of them over the years and they are a tough reliable unit. They were a HUGE seller, maybe still are. They came in different weight ratings, and if yours would fit you, I think it would be great behind your 6 speed trans.

4-speed-auxiliary-transmission laying out here i could use. but the weight and difficulty to install does not bring it to the top of my may fix problem list.

I agree, I've installed a few of them in the past and it's quite a bit of work. Plus by your pic, with the short wheelbase, you'd probably end up with too severe a driveline angle causing a vibration. The shorter the driveline, the less severe of an angle you can get by with.
If the RTO 11909 is the nine speed Roadranger, they're an excellent trans, assuming you have air brakes, you need air for the range shift. They were in lots of trucks the size of yours. There were even quite a few behind the huge Ford and IH gas engines, 543 cu. in. or whatever.

[Kaliburz]

Before seeing the pic, I was going to ask if this was on a dump truck....

The 8.3L is a good engine, but it's only rated at a max 300HP and I have no idea on the torque. I know it's not as torquy as the old NTC 290's and 300's (but those were huge engines). And who knows which spec on HP your Ford has. It could be the 250 or 275 version.

As stated, the axu trans would cause issues w/ the short wheel base. If you were a tandem w/ a longer wheel base, the axu trans would be "interesting". An old logging truck I know of here just got an old 5 & 4 tranny setup (5 speed main and 4 speed brownie) replaced w/ a 13 speed.

The two speed rear end would also work, assuming the the ratio's would be compatible. I have a C750 Ford gasser that someone put a two speed on (orginally a single ratio). Any how, in low, it has enough grunt, IF it's level ground. But it won't get past 45MPH. In high, it'll get to 55-60MPH no problem. You would have to find an axle w/ a low ratio to get the truck moving off road, but w/ a high ratio similar if not identical to your axle. Next issue would be your speedometer.... but w/ the mismatched tires...

The tranny swap would seem to be the quickest and easiet. I've seen tandem L's like yours w/ the 8.3L and a 10 speed or even 13 speed set up as tractor trailers (Pepsi/Coke/beer trucks). A friend w/ a Kenworth baby cabover (VW/Audi made cab) runs a 8.3L and a 6 speed. And you are right, the low range is a little to be desired. I'm guessing your truck is similar.

Your best bet is the tranny swap, be it a to swap in a 9, 10, 13 speed. Even if you are not an air brake, you maybe able to get one of those electric air pumps and a tank and that "might" provide enough air supply to shift the tranny (like the kits for airing up axu air bags for pickups/vans- all you need and doing is shifting a tranny from an air supply). Fixing a speedo cal issue would be easier also, if you care. The issue is the HP and torque. The 8.3L prob. isn't set up for that type of off road use, especially w/ a 6 speed.

OH, your rims for that year, assuming the axles are stock, should not be hub (center) pilot. They should be stud piloted using tapered nuts. Hub (centerP pilot came on later vehicles (if speced) and usually have a flat type washer/nut. Unless that axle you were talking about is a Dayton type wheel (aka California hub).

Well, keep us informed on the project.

[amunderdog]

RTO 11909 Is an 11spd it has 3 low gears then starts 1 at 7.41 ratio.
So the ratio's are about the same as currant trans with closer ratio's and three lower forward gears. three ranges of reverse also.
Sounds like my dream trans; but man the price $6800.00 so far for either the 10spd or 11spd.

I have air brakes on this truck and all air dump controls; So thats no problem.
The reason i have the Aux trans is the previous truck did not have air.

I have checked and like you did not believe it. But they are hub (center) pilot hubs and rims. Best i can figure?


This truck is listed as a 1994 Model but was built in 1993.
Last years of the old style diesels.

Who knows if it the original rear axle. But the steer axle is the same setup.
In it's second life it was on an asphalt job they may have needed the rear end up to match spreading equipment.

Thanks for helping me mull over my options.
What a mess

[Kaliburz]

I stand corrected on the axles.... must have been spec-ed by the original purchaser that way. Go figure. Guess you can't single out the rear axle or do the 'poor man' outer dual repair (aka put the inner on a block of wood to raise up).

That much for a tranny?! $6800. For that much, you prob. trade the thing in and get a different truck.... maybe. Even used NTC 300, 350's don't cost that much! (A local welding shop that has odd trucks just picked up some older class 8 semi's for like $2500 for the set! Both had NTC 350's and 13 speed trannies.... granted, one was mid 70's and the other mid 80's. Though both were cab overs...)

Another truck I have, a C8000 Ford has a RT-6610 behind the 3208 NA.

Unless I had the tranny or could get it cheap, I'd think I'd be able to find a different truck..... but that is me.

[amunderdog]

yes i am with you on the price of the new trans.
Thats about what the truck is worth.
I have found others of the RTO 11908LL for about 3500 - still about to much.
I think that other single speed rear axle i have is an Eaton disguised as IH
I may just try it.
You are probably right sell it and buy another.
But no one ever wants my Junk.

[Kaliburz]

With out knowing the condition of the truck and/or any 'reputation' that you have about equipment, it's hard to say......

The $3500 is a bit better, but like you said. If you don't feel it would sell, maybe another tranny would be the 'best' option. That's assuming you would actually get the use out of the truck. What is the overall condition of the truck? The bed? The engine? If this truck is in good shape, runs good, doesn't burn oil, etc, etc, then investing in a new trans may not be that bad. Plus, you could sell the old tranny to recover the costs also.... If the engine burns oil or has a 'condition' (leaking head, etc), then maybe it wouldn't be.

There are a lot of variables. A dump truck is a dump truck. And from the pic, it seems like a short one that gets into tight areas. A dump truck that a buddy has stored here is shorter then a pickup truck- he bought it from the local school for $1200 and it runs (old, 1968). Use to be a V6 GMC diesel (GMC truck), but was swapped when the engine went T/U by the local district. Now has the BIG GMC V6. People have offered him to buy it..... since it's so short. The GVW is like 24,000, hydraulic brakes. I think the bed will be 'full' before the overloads even compress.

[amunderdog]

This truck is in good condition for its age.
I just went thru the cab and got the rust out of it.
Everything works as it should but the A/C - needs a compressor.
The dump bed is a 10' late model. It has been abused but is repairable.
Short trucks are where it is at in my world.
Sometimes i wish i had a cabover. But they are bad about standing up on the tailgate.
I am really thinking about using one of the rear end i have.
Going to pull them out tomorrow and really see whats what.
Found a tag on the single speed rear axle today.
It is a Rockwell (hard to read) I think - IC 193201Y3431 but that number looks wrong to the decoders i have.
Am going to look harder at the 2 spd rear also.
Was reading old IH stuff today they claim on a two speed rear (the the low side will be 36% lower 6.71 on high and 9.14 on low)
All this thinking is hurting my brain.......
If i had the big money i could pick and choose; but this is what i have to work with for the time being.
Thanks for the feedback.

[amunderdog]

Well i cannot make anything i have here work.
Everything i have for parts has the small driveshafts.
The truck i am trying to fix has the large type.
So everything would be a major ordeal to make work and i would have to cut up some parts off the truck i am fixing.

First up is change drive axle about 1,000

Next is change trans which would mean a new clutch also, as the input shaft will be different about 4,000 and then changes to PTO on top of that as the tooth pitch and count will change; about 300 > Total about 4500

Or sell everything i have and try to get a truck that fits my needs better.
I have no luck selling anything.

The devil i know is probably better than the one i do not know. So i guess i am down till a can get the monies up to make needed changes.
Maybe my luck is changing? So while i am waiting i may try to sell some stuff to raise monies.

[Kaliburz]

Before getting too far, make sure you measure your frame width and the spring perches on the doner and your truck. The C8000 in my sig. is a "frankenstine' truck. Was lengthened and privouse owner swapped tandems. But it looks like they got the axle from a Freightliner....who's frame is narrower then 'standard'. I think Ford is different also, but I don't recall what my buddies said. Unless you want to try cutting the spring pads to relocate (which they did on mine), better check.

Well, there is always the "old" way to check the ratios. Jack it up and count the revolutions of the tire vs driveline. And (if I recall) the number seems way high, divide by two to make up for only one side being in the air.

Good luck.

[LMJD]

Sounds like the 2 speed rear end is your best and easiest fix if you find one that fits. As far as the speedo, 2 speeds come with a speedometer shift adapter which screws on the back of the speedo head then the stock speedo cable screws into it.