Need some assistance: 1981F100 4sp manual 2wd.
Vin:1FTCF10E6BPB01020

The axle code is 01, transmission code F.

The VIN is easy, but the axle and transmission are a mystery.

Can some kind person identify them for me or tell me where the info is?

Thanks, j66b

 

Should be a wide ratio T-18. Is it a 4 spd?

 

Bruno: Yes it is a 4 sp. I want to make sure it's not a RUG. The truck is a few hours away from my house or I just would go look at it. Gotta know before I go.

Any idea about the axle ratio from that code?

Thanks,JB

 

Ford 9" 2.75:1 ratio open carrier.

 

Don't be afraid of the RUG if the rest of the truck is what you want. The T18 etc are almost if not exactly a direct bolt in.

With that ratio, it might be a RUG, as Ford did some "gas mileage" specials with those ridiculous set ups. Note it's still running at this late date, so it can't be that bad. (flat roads and light loads only.....)

 

The T18 and low gears like that will be an excellent mileage combo

 

Thanks to all who replied. it is an 81 F100 300 6cyl, warner t-18, 2.75. I am going to drive three hours and see it today.

I have a 66 F100 as well with a 352, T19 (5.11) and a 2.75 rear. It goes 2100 rpm at 65 and gets about 18mpg on the highway. It had a Ford 3.03 and 3.5 gears when I bought it, and it got 11.

Gears matter. j66b

 

That exactly the same as my truck -- '81 F100, I6, T-18, 2.75 rear. I see about 17 mpg on average. With the Extra Low 1st of the T-18, she'll pull a house off the damn foundation. The 2.75 and 1:1 4th gear give just a touch under 2K RPM at 65 mph, which she'll happily do all day (Did a Coast to coast move with mine last year, never a hiccup.) The only think I might want for after driving it for 5 years is a different rear ratio, just to make the hills a bit less painful. Still though, you can't go wrong with it.

 

That cannot be too bad... I once had a 1984 F150 with 4 speed manual OD and 2.47 rear gears!!! If you even thought you saw a hill coming up, you needed to immediately downshift.

 

The biggest issue I have (mostly since moving to Seattle last year) is not winding it up far enough in 2nd before hitting 3rd. The 3.09 -> 1.69 jump is pretty damn wide. Then again, I've averaged only 200 miles /month since I've been here, maybe I just need to drive more.

 

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