Rear end gear ratio

[Albertduble85]

Present ratio a 3.33 and engine is 3500 rpm at 60 really roaring. Can’t keep up With modern traffic. IS says I need higher ratio like a 3.03 but manual says stock was a3.34: tranny is auto   3 speed. None of the parts dealers have any gears available. If I️ can find suitable ring and pinion will have work done by tranny shop as I️ don’t have expertise .

[brad]

A 3.07 was a factory option. readily available.

[Rob Dudley]

Mine has a 3:31 ratio and cruises at 3650 at 80. Yes it roars. We drove across Montana, Wyoming and South Dakota with it on the interstate. I think you should check to be sure of the ratio because the housings may be different. A good 4 wheel drive shop will be very familiar with these rear ends as they are common to Jeep. They will know what your options are and will have access to the needed parts. 

Rob

[Kennie B.]

Those numbers don't quite add up.

My car currently has the 3.73:1 ratio in the original Dana 44 axle.

At 3,000 RPM, the speedometer indicated 68 mph with the original Powershift transmission.

 I just finished the engine swap that included a T10 transmission.  The speedometer drive on the new transmission is set for a 3.31:1 axle which is what comes next.  With that, 3,000 RPM indicates 82 mph.

For the record, the factory manual shows the axle ratios as; 3.07, 3.31, 3.73, 4.09 and with a four speed trans 4.55.  That last choice requires a different differential.  There are all kinds of ratios available for the Dana 44 so do not dispare.  Jon Myers and Dave Thibeualt have gear sets as do Summit and Jegs.

Ken

[Rob Dudley]

2 hours ago, Kennie B. said:

Those numbers don't quite add up.

My car currently has the 3.73:1 ratio in the original Dana 44 axle.

At 3,000 RPM, the speedometer indicated 68 mph with the original Powershift transmission.

 I just finished the engine swap that included a T10 transmission.  The speedometer drive on the new transmission is set for a 3.31:1 axle which is what comes next.  With that, 3,000 RPM indicates 82 mph.

For the record, the factory manual shows the axle ratios as; 3.07, 3.31, 3.73, 4.09 and with a four speed trans 4.55.  That last choice requires a different differential.  There are all kinds of ratios available for the Dana 44 so do not dispare.  Jon Myers and Dave Thibeualt have gear sets as do Summit and Jegs.

Ken

Thanks for the numbers. Now I need to check my ratio and my tach. I have a powershift but that shouldn't make that much of a difference in engine speed. I am guessing that these numbers are for stock tires although it wouldn't make a difference one way or the other on indicated speeds (thinking as I type). 

Rob

[PackardV8]

Quote

None of the parts dealers have any gears available. If I️ can find suitable ring and pinion will have work done by tranny shop as I️ don’t have expertise .

Then you weren't asking in the most obvious places.  The Dana 44 is the most common axle design ever.  It was used by millions of Ford, Mopar, GM, Studebaker, Jaguar, Rootes, Nissan, Jeep, IH, Packard and a dozen others.  Literally every aftermarket gear manufacturer and every 4WD shop will have the gears, bearings and seals available.

There were two carriers, one for ratios from 2.56 - 3.73 and the other for ratios from 3.90 to 6.33.  You'll most likely be using the first and choosing from 2.56, 2.88, 3.07, 3.31, 3.54 or 3.73.

Also, the Dana 44 is still thick on the ground in the Studebaker community.  Put out a WTB over on SDC, listing the desired ratio, with TwinTraction, and you'll most likely get several offers to sell you a complete axle for a reasonable price.  You'll most likely have to change the brakes to Avanti and weld on traction bar brackets, but that's easily done.  You might get really lucky and find an Avanti axle with the ratios you want.  They're out there; just ask around.

jack vines