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Further to my recent question about differential ratios, I am still interested in seeing if there might be available a lower geared crown & pinion set for my truck. Trouble is I do not know what axle I have in the truck, it may be original ...I just would not know. All I know is, it is very high geared. What kind of ratio would I need to make the truck cruise easily at say 60 mph without the high revving that I have at present. I have had replies on that issue. Firstly what I really need to do is identify the axle that I have, can anyone help me with this problem please.
A picture of the rear of the differential housing would help us determine what model of axle you have. If we're talking about the truck in your avatar picture, then it's likely a Dana 41 or a Dana 44 depending upon the where and exactly when it was built. Again, a picture of the rear of it will help us determine which it is. New gears in more highway friendly ratios are available in either case - although the parts necessary for the swap aren't inexpensive. Also, look for a metal tag under one of the cover bolts and post any information on it.
can you tell me what bolt the tag usually was affixed to? I have a Dana 41. I had a tag on mine and I didn't take pics of which one it was fastened to. Just curious. Thanks
A picture of the rear of the differential housing would help us determine what model of axle you have. If we're talking about the truck in your avatar picture, then it's likely a Dana 41 or a Dana 44 depending upon the where and exactly when it was built. Again, a picture of the rear of it will help us determine which it is. New gears in more highway friendly ratios are available in either case - although the parts necessary for the swap aren't inexpensive. Also, look for a metal tag under one of the cover bolts and post any information on it.
Thank you very much I will get on that as soon as I can...I will post a pic as soon as I can.
A picture of the rear of the differential housing would help us determine what model of axle you have. If we're talking about the truck in your avatar picture, then it's likely a Dana 41 or a Dana 44 depending upon the where and exactly when it was built. Again, a picture of the rear of it will help us determine which it is. New gears in more highway friendly ratios are available in either case - although the parts necessary for the swap aren't inexpensive. Also, look for a metal tag under one of the cover bolts and post any information on it.
I have attached two shots of the axle. A close up of the diff unit and a full width pic. There is no tag as far as I can find. The axle measures approx 55 inches from backplate to backplate.
That’s definitely a Dana 44. Ring and pinion gear sets and all other rebuild parts are widely available and gear can be found in just about any ratio you can imagine. If it fits a Dana 44, it will fit your axle. BUT! The problem that you’ll run into is the carrier. The Dana 44 had a carrier split meaning that all gears sets 3.92:1 and numerically higher used one carrier assembly and gear sets 3.73:1 and numerically lower used a different carrier assembly. Your axle most likely has a 3.92:1 ratio as that was the most common standard ratio. You would have to pull the cover off and count the ring and pinion teeth to verify this for certain, but if your engine is wound out below 60 MPH as you state, it’s a safe bet that you’ve got a 3.92 or higher gear in your axle. You’ll probably want to swap it for about a 3.55:1. That’s a good compromise between highway speed and reasonable power for acceleration with an original engine. This will require replacing the carrier with a 3.73 and lower carrier assembly. The hangup with doing that is that these early model 44’s used oddball 19 spline axle shafts. To my knowledge, Dana never produced a carrier assembly for 3.73 and lower gears that would accept 19 spline axles. The solution to this dilemma is provided by the aftermarket. Yukon Gear produces the carrier assembly that you will need. It can be found here:
That carrier will accept the spider gears and all the guts from your existing carrier that fit your original 19 spline shafts and also allow you to run your choice of gears in a 3.73:1 or lower ratio. Good luck and have fun!
Since your truck is a '50, it's more likely that you have a Dana 41. Towards the very end of '50, Ford started using the 44. It makes a difference when ordering parts. Also the typical 41 was a 3.73 ratio, with an option for 4.27. Look carefully at the casting in the area circled, it will have either a 41 or a 44 there. If you pull off the rear cover, the tooth counts are stamped around the edge of the ring gear.
It would help us if you put you truck's model and year etc. in a Signature, you can add it in UserCP.
I’ve got to stick to my guns on this one. He’s got a 44. The sides on a 44 cover are squared off and a 41 cover is almost round. The bolt spacing is visibly different as well. Here’s a 41:
Yes, it does seem like he's got the D44, no telling if it's even the original axle this long after manufacture.
Yes, that's exactly right. I do not know if it is the axle originally fitted when built new. The stamping in the circle you mentioned in your first post....does that apply to the 41 and the 44 axles ?. I will get under tomorrow morning with a torch (sorry...flashlight), and see if I can read the casting text. Either way, I can see why people tell me it is far more cost effective to do an axle swap rather than change diff ratios. BUT I will still get some prices for crown,pinion and carrier. The downfall will be the cost of shipping and taxes to UK. I will let you know what I find tomorrow.
Dana UK in Birningham may well be able to help with this. I was going to get them to do the E-Type rear end, which I gather is pretty much a 44 in drag.
In fact . . . I wonder if I can kill 2 birds with one stone. The E-Type has a 3.54 rear end, which I want to swap to a 3.07 (standard UK-spec ratio). The truck currently has a 4.27 but I have a 3.73 axle as a spare. So I'm now wondering (from BlueOvalRage's comment above) if I can take the 3.54 gear set out of the E-Type and put it into the 3.73 cage in the truck, then just buy a 3.07 gear set to put back in the E-Type. Hmmm...
Dana UK in Birningham may well be able to help with this. I was going to get them to do the E-Type rear end, which I gather is pretty much a 44 in drag.
Hey good to hear from you. Thanks for the info...hows the truck coming along ?.
Hey good to hear from you. Thanks for the info...hows the truck coming along ?.
Hello mate. All good with the truck, thank you. Good to see yours is shaping up nicely too. I keep my original thread updated from time to time with any odd signs of progress. I'm impressed with the fuel mileage, even with the 4.27 rear axle. I reckon I'm getting 15-20 UK MPG from it. Trouble is, the oil mileage is about the same...!
