I am looking at re-gearing the rear axle of my truck to get some better cruising RPM's and speed. I have a 1955 F-100 and have confirmed the rear axle is a Dana 44 based upon design looks and the #44 on the lower passenger side of the housing. I believe it to be the original to the truck but do not see any date codes on the tubes. It has been painted and most likely the date code is too faint to see, and I really do not want to sand any paint off to find them if its not needed. I opened it up today and took a look at the ring and pinion to learn it is 47/12, or around 3.92. I searched around for awhile on the forum and learned if I want to go lower gear ratio I would need to source a new carrier. What I cant find is are the two types of dana 44 carriers the same for all years of this rear end? Every website I find selling carriers or ring and pinions say they will not fit once I narrow down the year, make, model. I am guessing the lower gearing I am looking for was not sold for these trucks originally so the websites say it wont fit?

I am looking at going 3.07 ring and pinion which based upon the calculator will be about perfect cruising speed/RPM with the FMX transmission in the truck.

So my big question is will all 3.07 kits fit if they are for a dana 44? and will all carriers fit if they say dana 44 (the carrier under 3.73)?

Thanks

 

Someone here may know more about this than me, but my understanding is our trucks have a different spline count on the axle shafts than what the later model 44's use, and the typical carrier on the market fits the later axles, not the early ones. You might do better checking with Chuck at Chuck's Trucks to get the right parts that you'll know fit your truck.

 

I believe Randy's Ring & Pinion (https://www.randysworldwide.com/shop...-spider-gears/) can supply a carrier and side gears, as well as the ring & pinion, that will work in your axle. Aside from the different spline counts, the side gears have different dimensions than more modern Dana 44's.

 

Just my opinion but I think a 3.07 ratio is too high. Experts here say a 3.50 is a better choice.

 

an automatic transmission non overdrive without a lock up converter will be perfect with the 3.07
Heck I got a 2.72 in my big window running a stick shift and I do like it. It runs so easy down the highways
3.50 would be nice with a stick shift or lock up converter or overdrive

 

It depends on the engine. A larger, later model engine, 302/351 and larger, has enough power to pull a 3.00 gear. That's what came in sedans back in the 60's-70's, before overdrive became the norm in the 80's.

 

I put a 3.54 in our Dana 44 from Randy’s. I would talk to one of their sales guys so you get the right parts. It’s worth it. Still has good low end torque but can hit 65 cruise without a big load on the engine.

JB

 

weren’t the earlier 48-50 f1 trucks typically geared with that ratio? They only changed to a higher one in 51 for whatever reasons..

 

I thought they were Dana 41 in the earlier years

 

48-50's came with 3.73 Dana 41's,
51-52's came with 3.92 Dana 44's

 

Thanks for the replies guys. I'll call around a little and see what I can find out. The engine is a 302, fmx combo out of a 75 f100 ranger pickup.

 

I've posted this several times and I'll do it again for you

i used a 2.72 ring and pinion from a mid 70s ford truck that had a Dana 44 300 6 cyl automatic

I used my 3.73 carrier and installed the ring and pinion on my carrier and my housing. Using my side gears and axles

the trick to this is the 3.73 carrier and I was fortunate enough to have that originally in my 56 as that was the optional gear ratio in 56

 

The Dana 44 had what is called a carrier break 3.92 up and 3.73 down. I have a 3.92 , I recently bought ( from Summit ) a auburn gear AUB-546085 LS carrier came with few oz of LS additive. 19 spline axle , a Dana SDH706017-1x ring & pinion 3.07 with installation kit .26 spline pinion, YGA-57003 carrier bearings(yukon). I also ordered a diffential and axle gaskets, and auburn gear oil. I had recently replaced the axle bearings. These parts are not installed yet, so I can't tell you how it went together. I am a little nervous about so many manufacturers. I was hoping to get to my mechanic and have this done this fall but a touch of snow and they salted mid-October.. I may pull the axle and take it to him this winter. I am not even sure I have everything I need. They also had 3.08 and 3.31 R&P. FTE research says anything from 2.75 to 3.50 would be good depending on what you want to do I am by no means any kind of expert on this (or pretty much anything else). Also if anyone sees something I missed, let me know please.. Dean

 

I have a 2.75 9" in my 55 with a mildly built 390 and top loader because I had it, thought it would be to high but tried it and I like it, 2500 RPM is about 75 MPH no problem at low speed

 

I took the axle out and took it to my mechanic in Dec. Its back in the truck finally. The only issue was the pinion was 26 spline and the original Dana pinion yoke was different.Not sure what the spline count was. I assumed being Dana ,it was the same ( wrong).He ordered 3 different ones ,26 spline but they didn't fit, they are 26 spline but different spline measurments. He finally called and ordered from Dana and got the right one. Its all back together but it will be awhile till winter is gone. So I can drive it. So its onto sound and insulation for now. Dean