That is a cool looking truck.
Any clue on how the 2 speed rear works with the TH400 auto?
I ask because IIRC the ones I drove you would let off the throttle, clutch in and switch rear end gear when going down a gear going up would be like below.


With no clutch would up just let off the throttle a little, "float the gear" and switch rear gear up or down?


The rear I am sure is nothing like over drive. The 2 gears (just saying) could be 4.56 & 4.11.


If looking for over drive:
A Gear Venders over drive unit will bolt to the rear of that TH400.
Crap forget that (maybe), I forgot you have 4x4 (4x6) and do not know where the transfer case is. If bolted to the TH400 then the GV OD unit will not work as the unit bolts to the trany.
If the transfer case is a unit by its self and I think it is you could use the GV OD


Advance Adaptors Range Splitter OD may work if the trany & TC are bolted together?
Dave ----

 

Dave thank you for your reply. I'm not for certain (I was very young when this truck was running last) but I think he just started off in high on the two speed.
As for the overdrive, that's a FANTASTIC idea! I remember this truck really spun the rpm heading down the freeway, so the overdrive is definitely something I'm going to look in to. The Transfercase is about two feet behind the transmission, so I should have plenty of room!

 

After I posted I was think of the that 2 speed rear, I know of a truck that also had a 2 speed rear but could not shift it when moving.
As you said you start off in 1 gear, around town low and before getting on the high way stop and put it in high.


If the TC is that far behind you could then go with the Gear Vender OD unit and a shorter drive shaft to the TC. That would help keep the RPM down.
Dave ----

 

I recently bought a good running 1971 4x4 F600 with split rims for farm work (hay, equipment and wood hauler), the 20" tires are good (first medium truck purchase; I have a 1979 F250 4x4 that doesn't quite handle what I want to haul--IH 706.) Brakes work but everything will be safety inspected before I try hauling heavy stuff.

I'm getting acquainted with the specs and was wondering if it is possible to use wheel adaptors to use 8 lugs rims for tubeless tires. I know there are one piece 6 lug rims for tubeless tires available from American Wheel in Pasco WA, no aluminum wheels available though. Any thoughts for restoring my sanity?

 

Welcome agstr. Are you wanting to use 8 lug tubeless wheels similar to those on your F-250? If so I fear they won't clear your drums. Adapters could be made by Arrowcraft or some other company to let you fit bigger 19.5" or 22.5" tires with the F-450 type 10 x 7.25" pattern, or large truck 10 x 8.75" or 10 x 11.25" pattern. But custom adapters aren't cheap. I've got to think a yard search would yield a set of not so old Accuride 28157 tubeless 22.5" x 6.75" wheels having your 6 x 8.75" pattern. Accuride no longer lists them brand new, but I bet an Accuride partner company like Wheels Now could get you a set. Stu

 

Thanks Stu,

I'll check the school bus yard to try and save some $$; there is an outfit in the Tri-cities, WA (American wheel; Home - American Wheel Specialist) that sells powder coated steel 22.5"x6.75" 6 lug wheels -- I'm also looking into a drum to disc brake conversion (mainly to increase brake reliability)--do you know of anyone that tried it to also enable more wheel choices, and to get around the difficulty of getting drum brake replacement parts?

And this is probably an insane, stupid newbie question but I'll ask anyway: can the 20" tires on the split rims be mounted on wheels for tubeless tires?

Respectfully,

Del

 

School bus yards and military surplus yards are good places to search. We are well aware of American Wheel Specialist, I have visited them and bought a set of their custom wheels. As I understand they are a wholesaler to Les Schwab and Commercial Tire which mean guys out west need to work through a local retailer. Guys like me further east and outside those chains can go straight to them.

There is a thread that has been going about a member making a disc brake conversion for 2wd and MH big trucks. Go back a few pages and you should find it. If you can't I'll help.

The tube type 20" tires are only gonna fit two piece wheels. Not tubeless. Stu