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Hey guys I have a thought in my head and searched but couldn't find any CONCLUSIVE information in the forums. I want to try to track down an R-10 or R-11 Borg Warner OD unit and I'm trying to find out if it will work with my 3HD tranny in my 56 F-100. Any helpfull info would be greatly appreciated. Thanks, Mike
I have a Y-block era 3-sp w/R-10-2 OD. I have had a devil of a time identifying the exact year and model of the trans; it has K-82 cast on it. How do you tell a HD 3-sp from a "regular" 3-sp?
I don't believe the OD's were ever used in anything but F-100's, always assumed it was a strength issue.
I ran a HD three speed in my F-1 when I could not hold the light duty transmission together. I got very good at replacing gears in the light duty trans. It was in the late 70's and I was running a 56 nailhead Buick. The F-1 HD three speeds were only floor shifters and they were a bolt in for the standard, light duty 3 speed. The easiest way to note the difference was weight. It must weigh upwards of twice a light duty (the trans is much deeper in the HD). First and reverse were square cut gears in the HD verses helical cut in the light duty.
I do not know if this all changed with the F-100's after the flatmotor was dropped from production.
Originally Posted by microb
I'm not sure but what little info I can find is based on the light duty 3 speed. I suppose they didnt use this tranny too much in the F-100s.
I don't think you can bolt an overdrive to the HD 3spd. I have one that was in my '51 F-1. It has more parts in common with the 4spd than the light duty 3spd. Our moderator Earl shows some disassembled pictures on his website as he has one. I heard once they used the HD 3spd up to 1966 but they would be extremely rare.
Ok I've decided to track down a complete T-85 or T-86 transmission with the overdrive unit to rebuild and replace my 3HD. I wonder what the difference in strength is between my HD and the Standard 3 with overdrive. Will this swap greatly reduce my towing capability?
Mike
In that case I should be fine. I towed a coworker's 80's chevy 3/4 ton from an uphill start in 2nd gear without any trouble. Thats probably the most weight I would ever tow with this truck. Thanks for the info. Is there a major advantage in the T-85 over the T-86 for this kind of use? Around here both are pretty scarce to find with the OD unit so I will probably take what I can find. I'm definately looking forward to having that .70:1 on the highway!
I have a t85 with overdrive, it came from a 73 f100 with 302. I'd be willing to take measurements and such or post pictures if you want. Its sitting on my basement floor for my 55 project with a 390fe . It also has the r11 overdrive. The t86 was the light duty version and was visually much smaller than the t-85. I'm not familiar with the two to be able to tell any differences between them.
I believe the T-86 was normally equipped with the R-10 OD unit. I believe the T-85 with R-11 is the strongest setup. I've been searching statewide for a T-85 and it seems they are pretty hard to find. The guy at a local wrecking yard it doing some searching for me and I'm keeping my fingers crossed. Otherwise I'll have to start searching further away. I'm pretty set on that transmission and OD unit for my 56 though.
They do show up on ebay now and then. There's a unit on there now, from a car, it has a slip yoke as compared to the bolted on yoke. The bolted on yoke was used on the trucks with a 2 piece driveshaft.
Thats what I've read as well. I wonder if there is an advantage though that bolt on has over slip for use on a one piece driveshaft such as mine. I know that I will have some shortening to do though as the OD transmissions tend to be longer than my stock 3spd.
Wow lynnandtina thanks alot for that link. I was sure I had found every piece of info (not too much) available on the T-85 and overdrive unit. Thanks again!
Mike