1955 t-bird 4.10 gears to replace 3.31

[39deluxecp]

Can I replace the 3.31 ring and pinion in my 1955 tbird with 4.10 gears? It is a Dana 44. I have read info about thick and thin gears that require different ring gear carriers. Thanks

[Hot Rod Reverend]

I would think that 4.10's are out there... but, what transmission are you running? Without an overdrive that 4.10 ratio would be might tall!

[rotorwrench]

Earlier overdrive cars like the later 1950 through 51 Mercury and Ford station wagons used the 3.92:1 gear sets and had the 19-spline axles but it depends on what your application is. Randy's Worldwide has Dana 44 stuff that will work for the early Dana 44 including the carrier for 19-spline axles. The taller gears use one diameter carrier and the larger numerical ratios use another. 3.92:1 is the split point so a 4.11:1 would use the same carrier. The Ford Pickups may have the 3.78:1 if it's from an early F1 with the Dana 41 but the later 1950 and on may have a lower ratio with the Dana 44 but it's hard to say. 3/4 ton & larger have a different axle. The 9-inch came out in 57 so cars quit using the Dana 44 but F100 pickups kept on using them for a long time. Cars with the automatic transmission were the only ones to use the tall gears like that but they can work for a manual transmission too.

Why do you want to change them? A lot of folks look for a good set of the 3.31:1 gears if they want better highway performance with a 3 or 4-speed transmission.

[miker98038]

To add to what rotorwrench said. In the late 60's, I pulled the 3.31's out of my 55 bird and stuck the rearend from a 56 6 cyl o/d wagon in it. That was a 4.27 or 4.30 ratio. IIRC, I swapped the brakes, but not the backing plates, put lowering blocks in it, and that was it. My current bird has a Dana 44, but it's a truck rearend bigger axles, and was a 4.11. My point being a lot of those got changed over the years as it was cheaper from the junkyard than to rebuild or replace. So look close at what you've got, as opposed to what you should have.

I'll second Randy's , their main office is an hour north of me, and they provided everything I've used thru a couple ratio changes. They've now got an office in MN, so they're not that far from you.

https://www.randysworldwide.com/?gcl...SAAEgIP-PD_BwE

[39deluxecp]

when I rebuilt the rear end I counted the teeth so it is 3.31. I just drive around town and run through my private( highway 59) dragstrip at times. I installed a 351c and a manual shift C4 , so rpms wont hurt it. I just need to know if the 4.10 gears will fit in a 3.31 case and carrier. thanks for all the help.

[Ole Don]

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A Ranger rear axle should fit, one from a 4x4 Super cab with a factory hitch should be a 4.10. It will also have the big brakes.

[miker98038]

If you're asking if the 4.11 gears will fit in the 3.31 housing, best I know the answer is yes. I know it'll work the other way, and best I can recall the rear cover gasket was the same on my 3.31 rear ended as it was on the 4.27 I bought to replace it. You will need the correct carrier for the 4.11's, as rotorwrench points out.

As to what you have, there's also a difference in the axle and bearing sizes between various units used by Ford in the same time frame. Bird, wagon, police units, and trucks, may or may not have been different. Worse, opinions and experiences seem to vary on this. So you'll need to look. Randy's can help with that I think.

A word of advice based on experience. Changing the gears is time consuming, even if you pull the rear end out of the vehicle. Expensive if you have to hire it out. With a 351 and a C4 in a bird, you're going to want some form of limited slip, and that's more money. You may also find the housing and tubes are warped or leaking. Been there and done that, too. Much easier if you can pull the center section, and have 2 if needed.

If I were doing this again, I'd find a more modern rear end as Ole Don suggested. I could have a custom 9" in my bird for the money I've spent screwing with the 44 over the years from engine and transmission changes and needing to change ratios. Not to mention the better brakes using more available parts.

[39deluxecp]

I checked out Randy's world, very good. I will call them tomorrow . thankyou!

[JeffB2]

We have seen a lot of guys using the 8.8" rears from Rangers and Explorers in 50's Fords over on the H.A.M.B. the later ones usually always have a locker rear end and stouter 31 spline axles this will give you Tech info on them: https://therangerstation.com/tech_li...8_8-axle.shtml Usual going price at most Pick-A-Part places are around $200 we have had a couple members score them on half off special days. Video on narrowing and moving the leaf spring pads: https://www.youtube.com/watch?v=mayY...ture=emb_title

[paul2748]

Probably the best way to change is get a 57 Bird rear (9 inch) and then get the gear ratio you want aftermarket.. 57/58 sedans are a bolt in, but you will have to use lowering blocks to maintain stock height.

[39deluxecp]

called a gear outfit and they said a thick ring gear will work with the 3.31 carrier. so I am keeping the Dana 44. If it goes south, then i have a 9" to replace it . thanks .