1950 Dana 44 Gear Ratio

[kirkf]

I have a 1950 Ford F1 I'm slowly rebuilding and I was curious whether anyone has any experience with the alternative ring and pinion choices available.

I realise most people have gone with Ford 9" differentials when they wanted to change the rear end gearing, but who has changed the ring and pinion in their stock Dana 44?
I would be interested in hearing what ratio people went with when retaining the stock drive line.

There appears to be a wide range of ring and pinions available these days:

https://www.ringpinion.com/


Does anybody have any experience/advice with the best ratio for a regular driver?


Thanx,


Kirk

 

[rotorwrench]

The best bet is to contact Randy and ask him. There are different size carriers too so you have to make sure that the ring you want will fit the carrier you have. The axle spline count can have an effect but there is stuff available for both the early and the late spline types.

My old Mercs have the 3.92:1 ratio but the overdrive works well with that.

 

[Ol' Ron]

Are you sure it's a Dana 44. I thought that year they were Dana 41's. However 3.73 makes a good all around ratio.

 

[Ross F-1]

Are you sure it's a Dana 44. I thought that year they were Dana 41's. However 3.73 makes a good all around ratio.

Correct, 48 - 50 were 41's, 51 - on were 44's. I believe Randy's can deal with either.

 

[rotorwrench]

Dana 44 started mid 1950 model year for Ford F1s and Mercury cars. A person can always tell by the shape of the rear cover and the little 44 cast into the center section of the right rear lower area below the bulls eye.

I don't think the 3.73:1 was available with the Dana 44. The Dana 41 had the smaller carrier than the 44 in that time frame.

 

[4t8v8]

Rebuilt my Dana 41 using Randy's all the way. Had everything, fast shipping and excellent prices. If you do have a problem finding parts, early Jeeps used the same rear end.

 

[Kahuna]

For a bunch of info, go to any Jeep forum.
The Dana 44 is a very popular rear end

 

[49r]

I fitted a 1956 F100 Dana 44 into my 1949 F1 - no alterations needed. It has the 3.73 ratio (41/11) which I find a pretty good all-rounder with 6:50-16 tyres on the rear. I have my stock Dana 41 (yes, check this isn't what is in your pickup) which is a 4.27 ratio (47/11) - good for one gear driving but over-revving at 65 mph.

I'm in the process of fitting a 3.55 ratio (39/11) to my Dana 41 as I would like the original looking diff with a slightly lower cruise rev (all of about 150 I think compared to the 3.73). I used the 8C-4209-HS ring and pinion which Early Ford V8 and Motive Gear Performance sell. The ring fits my stock 4.27 carrier. Early Ford V8 supplied all the bearings and seals 8C-4200-KIT. This didn't include the planetary gears which EFV8 have also. The only item they were out of stock on was the cross pin which I think is the same as the Dana 44 (SLXP-D44) which I purchased from Randy's.

 

[kirkf]

I had a chance to take a good look at the dif tonight and I think you guys are right about it being a dana 41.

I found what looks like a barely legible 41 cast into it and I didn't find anything that looks like a 44. (See attached pics)

Kirk

 

[rotorwrench]

It's definitely a Dana 41 (has the round cover). Most parts interchange between the two but the 41 has the smaller carrier diameter so if your looking to change ratio, you just need to make sure the ratio R&P you want will fit. A lower ratio likely will if you do some checking around. It might have a larger carrier if it's a stump puller ratio so count the teeth and find out what the ratio is. It was originally stamped on the little metal tag but if it's gone just do the tooth count like 49r mentioned.

 

[kirkf]

I counted the teeth and it looks like mine is 41/11 (3.73) ratio right now.
Which isn't as bad as I was expecting it to be.

At the minimum I need to change the outer pinion bearing (the rollers are visibly shot), the pinion seal and the outer axles bearings and seals.

Kirk

 

[rotorwrench]

The early pinion seal set up was changed in later units so they can be harder to source. They can be changed over to the later type seal if need be as long as all the right parts are used. I've converted s few early Dana 44 pinion seals but I've not done a Dana 41 yet. All the other bearings, seals and gaskets are interchangeable with the Dana 44 as long a it is 19-spline axle type. The 3.73:1 is a good ratio for overall use. Not too fast but not too slow either and it still has good pulling capability. The 3.55:1 will suffer some for load hauling but will give excellent top end.

 

[kirkf]

According to this table, the two available drive gear ratios were 4.27 and 3.92.
Since mine is 3.73 is it likely that at some point someone already put in the drive gear and pinion from a later dana 44?

How do you positively ID them?

In the pics I took I can see an 8C stamped into it.

Kirk

 

[49r]

My Dana 41 carrier (4.27 original ratio) has 8M-B-1 stamped on one part of it and C ford (script) 948 on another. The diff housing has 8M 4025 stamped on it, along with 427 on the RH housing tube. Being a kiwi my pickup is Canadian so there may be part # differences from USA models.

 

[rotorwrench]

The 3.73:1 ratio was used from 1948 into 1950 for the Dana 41 from the Ford truck parts books. The Dana 44 used the same ratios as the Mercury from 1950 through 1951 and maybe on up in Mercury & F1 pickups through 1952 or 53. The Numbers in that chart are for Dana 44. The OM prefix gears were early Dana 44 in 1950 Mercury. The Mercury axles are interchangeable with the F1 but the housing spring pads are different so would have to be changed to swap them. Ratios can be changed in all the Dana 44 axles but you have to confirm changes to the Dana 41 since the housing is different and doesn't have the same amount of room inside.

 

[Ross F-1]

In late '50, there was a standard ratio of 3.73, the optional 4.27, and a rarely seen 3.92 using the D41 bits, with different tooth counts compared to the 51-on D44 3.92's. I've only heard of one 3.92 in a D41.

The 8C stamping is consistent with the parts book.

 

[rotorwrench]

The 8C was a very common Dana 41 ratio for F1 pickups but that changed with the Dana 44. A person can use them in a Dana 44 with no problems but the carrier would likely have to be swapped with it. I'm pretty sure all the different carriers will fit the Dana 44 but not all will fit the Dana 41. In the Mercury cars they called the 47/12 ratio 3.91:1 even though they are about the same if rounded up.

 

[kirkf]

Thanx for all your help everyone.

I'll give Randy's a call and see what I can do about getting the necessary pieces for the Dana 41.

In the meantime however a Dana 44 also popped up from a 52 F1, so I picked it up as well, so I have my bases covered either way.

Thanx,

Kirk

 

[kirkf]

49r,

I'm in Canada, so my truck is actually an F47.
Its always a challenge trying to sort out the subtle differences between the Canadian and US built vehicles. Of course almost all the information is for US only.

I spent a very bit of effort trying to figure out what the exact beige colour of the motors was supposed to be, but that information appears to be lost forever. (Cummins beige appears to be the go to colour)

Kirk