I Need Information About The Single Speed Transfer Cases

[ihscoutlover]

My truck-to-be is a '77 Traveller. It has an automatic tranny, A/C, cruise, and the single speed xfer case. I want to know if this is a reliable case and what kind of action I should expect out of it. I know that it goes into either 4x4 or 2x4, but what kind of ratio of gearing does it put out?? My scout II '77, has the two speed xfer case and I know that it gives you high and low range 4x4, but what make the single speed so rare or special?? I don't have any specs and want to know a little more about it. Thanks for any replies.



Jeff

[Barney]

The single speed has no gear reduction, it is a direct drive. From what I have heard it was made by a small parts vendor for IHC. I have had one in my 1210 since 1986 when I converted the truck to 4 wheel drive. It took me many place off road when I used to hunt, deep snow/ mud, and alwas got me back home. In the pickups it sits about 18 inches behind the tranny connected by a short driveshaft. The only thing I ever did to it was to change the Yoke oil seals when I first installed it. I also switched from the reccommended ATF to straight 50 motor oil. I have put about 100 000 miles on it since 1986. I don't 4wheel much anymore but it is still going strong. Parts availability may now be a problem.

[Baradium]

it's a 1:1 at all times...

[alfscout]

I wrote an article on the transfer cases used in IH trucks for the Swedish IH Club newsletter a few years ago. The chain-driven case you are referring to was used from 1974 in the Scout II and is called TC-143 (if it was built by a small parts vendor I don't know). It uses a 2" chain and the house is made of aluminum. The weight is 22 kgs (about 50 lbs). It takes 1/2 a litre of oil (about a pint). According to technical bulletins from IH the oil should be changed once a year. If your Scout II has an A/T you should use Dexron ATF oil, but if it is a manual you should use regular gear oil SAE 90. However, a thread from web site signed by Chris Leggett recommends Dexron ATF oil in both cases. I used ATF oil without problems, but then the gears started making a lot of noise when I changed to 4WD. Instead of trying to find spare parts I decided to put in a regular TC-145 transfer case with Hi and Lo. The price is about the same, at least over here in Sweden. Good luck with your Traveler!

[Dennis Bernth]

Parts are evidently still available, the PO of the 73 Scout II I bought spent around $700 getting the single speed rebuilt in it about a year ago (so I could yank it out and put in a Dana 20 ). They're OK cases if you don't need low range, but if it died I wouldn't put dime one in it with Dana 20's being as plentiful and cheap as they are. I'd have one of those on the shelf along with the bull gear as insurance, you'll also need the Dana 20 driveshafts. Sounds like an excuse to bring home a parts truck to me....

[ihscoutlover]

Originally Posted by Dennis Bernth

Sounds like an excuse to bring home a parts truck to me....

I have a parts chassis that I paid 100.00 for and it has the 304, dana 20 tcase and dana 44 axles as well as driveshafts and chrome rallye wheels. Thanks for the information you guys and gals.

Jeff

[ihscoutlover]

Another couple of questions though. How does the control work? Is it a cable, or a shifter? What is the "reliability" of this xfer case. And would I be better off changing it to a 2-speed case? I also would like to know approximately how many scouts, travellers and terras had this kind of case. Thanks for the input.



Jeff

[Barney]

The single speed is controlled with a push/pull cable. It can be safely shifted on the fly up to 65 mph by momentarly backing off the throttle while you pull the cable, disengagement is the same by pushing in on the cable. As stated in my previous post I have put over 100 000 on this transfer case without any problems in my 1210 3/4 ton. I got the transfer case out of a parts truck that had been rode hard and put away wet many times. One VERY IMPORTANT POINT it can only be shifted safely while moving!!!!!!!!!!!!!!!! I have been told it was not that common in the pickups but more common in the Scouts.

[Dennis Bernth]

Originally Posted by Barney

The single speed is controlled with a push/pull cable. It can be safely shifted on the fly up to 65 mph by momentarly backing off the throttle while you pull the cable, disengagement is the same by pushing in on the cable. As stated in my previous post I have put over 100 000 on this transfer case without any problems in my 1210 3/4 ton. I got the transfer case out of a parts truck that had been rode hard and put away wet many times. One VERY IMPORTANT POINT it can only be shifted safely while moving!!!!!!!!!!!!!!!! I have been told it was not that common in the pickups but more common in the Scouts.

I'm going to disagree that the single speed can only be shifted safely while moving. Sitting still and shifting into 4 wd is the ONLY way you can do it if you have Auto hubs and they're in the 'auto' position. And, if you try to shift into four wheel drive running down the road at 65 mph with the auto hubs set to 'auto' or manual hubs unlocked, you better have that Dana 20 standing by, you're going to need it. Removal of the old transfer case will be pretty easy, since it probably removed most of itself when it engaged You CAN shift into and out of four wheel drive (including HIGH four wheel drive with a two speed, gear driven case) if you have your locking hubs locked in, or your auto hubs set to Lock. In that case, the front driveline is spinning at about the same speed as the rear driveline and it should engage fairly smoothly, although 65 mph might be a bit much- I think 40 or so would be the upper limit, and I doubt you'd ever need 4wd if you're going that fast anyhow. But, going to 4 wd in any transfer case while moving with the front driveline disengaged won't work. You are trying to mesh the rear driveline that is spinning 40 mph and the front driveline that is standing still. Transfer cases (the ones used in our trucks anyhow) don't have synchros, and they aren't made to have a soft engagement where it starts to slide in and brings the other driveline to speed; they're either in or out. No difference there between the single speed or the Dana 20. As for swapping out the single speed, I did, but mainly cause my Scout doubles as a snow plow truck. When you have wet deep and heavy snow, low range is about a requirement to keep the trans alive. I had a low mile Dana 20 and a bull gear along with the driveshafts laying here, so it was a simple swap. If you mainly are going to run on the street and maybe a little light wheeling to get here or there, the single speed should work fine. I was able to show up some much bigger pickups with big tires, lifts and two speed cases with a 73 Scout II with a single speed case and 235-15 snow tires back in the late 70's when we had some massive snow storms that shut everything down. That thing would motor right on through stuff that would stick other trucks, but then I didn't have to push the snow, I was just driving through it.