1975 500 Info

N

netpro

New member
Looking for information about the 1975 (light Line) 500 Series international trucks. I recently purchased a 2wd 1975 International dually truck that I would like to convert to four wheel drive. The truck has a very heavy frame and leaf springs up front already. I would like to learn more about the options or original components that came on the 500 series trucks and possibly use a similar configuration to what came from the factory for the 4wd conversion.

If there is a publication that will provide information regarding the axles and other drive train components that were options on the 500 series trucks please let me know what publication that might be. My research so far suggests that the 200 series duallys often used Dana 70 front axles and sometime Dana 70 rear axles and sometimes International RA rear axles. Would the 4wd 500 series have used the same axle series or something heavier? Were there heavier versions of the Dana 70 and if so how are they differentiated from the lighter versions. Were the transmissions and transfer cases the same as the 200s or heavier as well.
 
Hi Netpro, Welcome to the wonderful world of International. I'm sure someone here will correct me if I'm wrong, but I think anything bigger than a 300 is considered a medium duty truck. As a Loadstar 1700 owner I know there is not much info out there about these trucks. For the front axle, I'd guess that if a D70 is used it would have thicker tubes and bigger knuckles to handle the weight. What are your plans for this truck?
 
Thanks for the reply FDChappie. Was there a 300 series? From what I've researched in 74 IHC changes the Light line numbers to 100, 150, 200 and 500. for 1/2, 3/4, 1 and 1 1/2 ton trucks. Did I miss one. I've been reading forums and such all over the net and as soon as I think I understand something something else pops up and confuses things. I've owned a couple of IHs before this - most recently a 1700 that was previously a roofer truck that had a dump/scissor lift bed. Came in handy for some landscape hauling and then a little later for the roofing I did on a shop I built but then it sat and it was time for a new home. This truck was pretty beat up and while I did at one point consider replacing the cab on the truck but given the little I used it the license and insurance on the thing was eating me up.

This 500 came along when I had been planning to convert a 71 Chevy C30 dually to 4wd. I had been researching that project for a while - collecting parts, but I was a little overwhelmed with the necessity to replace the front end cross members and A-arms and such when there was never a leaf spring version of the C30 in that year range. I didn't really know about the 500 series Internationals - I just knew that the truck was much heavier built than the C30 I had - but International overbuilt everything right!. While I had looked at some International dually one-tons before most had A-arm suspension like the Chevy. This 500 was the first one I'd seen with front leaf springs so that meant the 4wd conversion would be simpler.. I really don't need the extra weight carrying capacity but it would be nice to replicate a factory 500 if I can find the right parts.

There is a picture floating around the net that is of what was apparently the last Light line truck to come off the assembly line in 75 or 76. It is a four-wheel drive truck. Wikipedia says the last truck off the line was an All Wheel drive 200HD. I cam across a Pinterest post that says that it was a 500 four wheel drive truck.

There is a Loadstar 1600 4x4 for sale on e-bay right now that claims to have a Dana 70 front end but it doesn't have the traditional Dana60/70 pumpkin cover. (See attached picture. Perhaps I should contact the guy selling that truck and see what info they have on the front diff. To me the 1500/1600/1700 loadstars are a definite step up in truck size but I did read somewhere that the 500s didn't sell that well because generally buyers in that category were opting for a loadstar instead. I also read that some of the transmission choices that International offered applied to both the llght line and the loadstars though so it is certainly conceivable that the differentials could overlap as well, The rear differntial currently in the 500 is much larger than any Dana 70 I've ever seen and I expect it is an IH axle. If memory serves me correctly it is smaller than the diff that was in my 1700 but not by that much. It's certainly conceivable that the Light Line 500s and the Loadstar 1500s would have used the same drive train so that's a very good point. Was four wheel drive a factory option in the Loadstar line in 75?

My plan is to make this truck a vehicle I can use for medium duty trailer towing. I have a dump flat bed that will go on the truck. It appears that the previous owner had been taking steps to restore the truck. The cab is in very good condition without rust holes but it is primered and all the door handles and stuff were removed in preparation for painting. The engine compartment firewall was painted and the engine was painted and there isn't a spot of oil on it. This suggests to me that the engine may have been rebuilt and perhaps never even run since the rebuild. Everything is very dusty but a look under the air cleaner cover suggests the carb is new or rebuilt. I need to see if I can get the engine running but I haven't made the time to do it. The line set sheet says the truck came with a 345 but if it was rebuilt then it may or may not be original though it is definitely an IH motor. The tranny is definitely a four speed but I'm not sure which one or how to identify it.

Any and all information is welcome. Thanks again.
 

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There is no 300 series in the D line. The D-series 500 trucks are covered by IH parts catalog MT-136, available for purchase through Binder Books, which is also conveniently owned by IH Parts America. My quick scan shows that there is no front driving axle option listed for the 500 in the catalog. That doesn't necessarily mean that none were special ordered with a front driving axle. Maybe it just means there weren't enough of them spec'd that way to justify a parts listing in the catalog. That's just my assumption.
 
Thanks ScoutBoy. I didn't know there was no 300 in '75. It also looks like the series started with a 150 half ton. So what is the weight rating of the 500???
 
IDK what the GVWR is. Maybe Netpro can tell us what his is. The FA-28 I-beam that they came with has a 4000 lb rating, as does the FA-52 Dana 70 driving axle that could be optioned on the 200/250 trucks.
 
Thanks for the additional info guys. The LST says the GVWR is 13,840. It calls for a FA-28 4000# front axle and a 10,000 rear axle and spring with 9,840# tire/rim. The truck has five lug split rims and 750/17 tires. It says there is an RA-20 housing and a 4.87 ratio carrier.

I was thinking I might need a heavier front axle than even a standard Dana 70 but it sounds like I would be ok with Dana 70s front and back but that a Dana 60 up front and a Dana 80 in the back would be a better and more modern combination.

Does the parts book show any four wheel drive elements for the 500 like a transfer case. I wonder if four wheel drive was a factory option for these at all. I've seen lots of medium duty FWD trucks from that era online but I think a lot of them are aftermarket conversions by Fabco or Harrington - mostly for utility companies from what I've read. I wonder if the 500 4wds might be aftermarket conversions also.

What is a 250? Haven't heard of that one before.

My research suggests that less than 7000 light line trucks were built in 1975 - the last year of production. Does anyone know if there is definitive information relative to how many of each model were built in each year?

The LST says this 500 came with a T427 4 speed WG trans. Does that translate to a more standard transmission from a major manufacturer or is it IH specific?

Thanks again for the info - any and all info welcome - including info about drive trains in the Loadstars of the same era since there may be some crossover.
 
Oops. No 250. Sorry for the confusion. There is a 100 and a 200, half ton and 3/4 ton respectively. Then the 100 changed to a 150 I think for the '75 model year and I was incorrectly assuming that number convention carried forth with the 3/4 ton as well. No other vehicle manufacturer on earth went further out of their way to create needlessly complex and confusing model numbers than IH did over the years. Just my humble opinion there. The RA-20 is an IH corporate axle and thus not a Dana of any flavor. For a transfer case, I think it would be a fairly simple matter of sourcing a New Process NP205 divorced transfer case as would have come with a lighter 4x4 pickup/Travelall. The 500 frame is different from the lighter truck frames. I don't know if there are provisions in the 500 frame for the t-case crossmember to attach, but could probably be fabricated if necessary. Drive shafts would of course be another issue to address. Shafts from a 200 4x4 would possibly work. WG stands for Warner Gear as it applies to your 4 speed trans. It is not a proprietary IH unit. It is what's known as a wide-ratio 4-speed with a super creepy low first gear ratio in the neighborhood of 6.32 to 1. You'd mostly be using your 2nd through 4th gears, especially when empty and on flat ground.
 
I have an NP205 which I was planning to use. It was from a 90s dodge and came with a PTO winch. My understanding is the divorced NP205 from the Dodge should be the same as what was used in the 75 International. My research to date suggests that all of the 4x4 69 through 75 Light Line trucks used the NP205s. I'm still looking for an International crossmember for the NP205.

I would be interested to know if anyone knows definitively if IH built factory 4x4 500 series trucks in 74 or 75. It sounds like the parts manual does not support the existence of a 4x4 version of the 500. It would be really interesting to see an LST from a 500 4x4.
 
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