Folks,
I promised I have tried to search for an answer to this. However to no avail.

I have a 1974 F250 highboy crewcab. on my warranty tag the axle code is B4R. The B4 part, no problem. the R part?!? accordignto the decoder and all images of the MPC I have seen the R code front axle was not available on '74 trucks. To be absolutely clear: myfront axle is a DANA 60F and I have power assisted steering. Also it was a government DSO, so maybe that has something to do with it.
Was the R code a typo on my warranty tag or???

 

If I had to guess, I would say high pinion differential with REVERSE cut gears. Is it a high pinion?

I'm a little surprised that an f250 would have a D60. I thought they were D44s

 

X2 on I bet the "R" is for a reverse cut gears. DSO.. who knows what was special ordered.

Dana 44 more common, but a Dana 60 under a F250..not that uncommon.

https://www.ford-trucks.com/forums/9...mpilation.html

"Front axles were an 8-lug low-pinion Dana 44 (1967-1977.5), 8-lug
low-pinion Dana 44HD (1969-1975), or 8-lug low-pinion Dana 60 (1973-1975,
Crew Cab Highboys only). There were no high-pinion front axles in
Highboys, although high-pinion front axles are preferable to low-pinion
front axles. The Highboy front axles were a closed-knuckle design from
1967-1975, and open-knuckle design in 1976-1977.5. The open-knuckle
design is preferable. Many Highboy owners replace their low-pinion front
axles with a high pinion 1977.5-1979 Dana 44, or better yet, the 1979
high-pinion HD Dana 60 with 35-spline inner shafts and 30-spline outer."

B4 Dana 5300 3.73

The Dana 60 bible: BillaVista.com-Dana 60 Front Axle Bible Tech Article by BillaVista

http://77cj.littlekeylime.com/Dana60.htm

"I'm covering the Dana 60 as it came under the Light duty Pickup. Dana 60 Reverse Spiral was first released in Early 1977 under Ford F250 & 350's 1977.5. This axle has also been called the Dana 60 High Pinion, Dana 60 Reverse Rotation, Dana 60 Reverse Cut, Dana 60 High clearance and many more names."

 

I'm gonna say this is a low pinion. lol. also the casing is clearly stamped "60 F".

 

R = replace with high pinion open knuckle disc brake axle. lol.

 

And I see a front axle with a closed-knuckle design from
1967-1975.

 

B4R:

B4 = Dana 60 rear axle / 4.10-1 / Limited Slip / 5,300 lbs. capacity.

R = Dana 44-6CF or Dana 60F front driving axle with 3,800 lbs. capacity & power steering.

 

And there you have it.

 

Is it a late-'74 model by any chance? If you find that they were not "officially" available in '74, then that might explain why there is one under yours.
And if ND's info applies to '74's with no problem, then the previous info about them not being available was probably just wrong.

But also the DSO could easily have something to do with it. There were a lot of Gov't GM Blazer/Jimmy's delivered with Dana 60 front axles back in the seventies too. Those were extremely sought after by those that knew what to look for. We used to see tons of them around here. Very heavy duty and cool rigs.

Paul

 

Well, my number is in the high "S8xxx"s, making it pretty much in the middle of the '74 builds, and I doubt they were running out of 44's. My take is it was due to the government DSO.
it will be interesting what the MR says when it arrives.

 

F-250 crew cabs normally came with low pinion D60 front axle.

 

1974 serial number range: S60,001-V20,000

Production date printed on the upper left corner of the Safety Standard Certification Label, glued to the left B pillar (door post) below the striker plate.

 

Thanks for all the replies and info! ND, the truck was resprayed (badly) a decade before I got it, so no identifiers other than the warranty tag and the build sheet under the rear seat cushion survived.

My thread was more of an observation of the R on my warranty tag being odd or interesting for a 1974. Would have been interesting to hear of another like it. I am 95% sure my truck's drivetrain was mechanically stock when I got it. I know I have a Dana 60 LP 4:10 with close knuckles on the front and that is what was on the tag and the build sheet. I'm just saying it was coded weird as an R in 1974 when the book says that code was used until '75.

Thanks again.