I have a 56 Montclair Convertible that I replaced the automatic with the 3 speed & overdrive.  I left the rear axle in and will probably change it.  I have an axle out of a 56 Medalist with 45/11 tag on the rear axle (4.09). I haven't taken it apart to confirm.  I haven't found any information that shows a 56 Mercury with a 4.09 ratio.  Does anyone know what this came out of?  Would this  be a 9 inch ford axle?  Any help would be appreciated.  Thanks Larry

Larry

If the rear end has a removable plate on the rear its probably a dana from a mercury,i have one that was removed from a 55 merc with 3 speed overdrive and its a 4.09 gear  Carl

I have a 4:09 in my '55 Merc Monte. It's original and the manual specifies it to be used with the 3 speed with OD. It's a Dana, buts it's a Dana 45, not a 44.There's precious little info available on the web, but I did find that they were used in Scrubby trucks of the era as well as other makes. Parts are made of unobtainium but Dana 44 parts will substitute with some creative shimming. It and the T-85 are much stouter than needed for the original low HP 292 or even a 312. It's almost as if Ford was anticipating the advent of the MEL and FE series engines as early as '55.

Thanks for the information.  I dont know what a scrubby truck is.  Has anyone used this low geared rear axle in the 3 speed with overdrive?  It seems a little low.  It may be out of a 55 as I had some 55 parts.  I will check on a dana 44 to see what I can find.  Thanks again.  Larry

Larry

"Scrubby" is a "Chebby". The One U drive to see the USA.

  

The 4:09 works fine as long as your OD is functional. In OD the effective final drive ratio is 2.86:1. With my tires 70 on the highway is about 2800 RPM. 

Dobie, what size tires are you running?

Carl and Dobie:  Does the 409 rear axle work well with your 3-speed transmissions?  My  has the -speed with overdrive and a rear axle designed for the merc-o-matic which is to high.  It seems to me it the rear end should have a ratio of about 370.  I also have another rear axle from a 55 or 56 merc that is 307.  I will have to check the ratio on the axle in the car.  Thanks Larry

Larry

Tires are 215/75/15.  The rear axle is 41/13.  Both axles in the back are marked 45 A by the filler plug.

Larry

Sorry for my disjointed comments.  I have 3-axles all marked 45A.  The one in the car is 41/13. One in the back is 45/11 the other is 41/13.    I generally use it for short trips as we live in a valley where a long drive is 30 miles round trip.  I very seldom take the car on the highway.  It looks like I have two axles for an automatic and one for a standard.  So I guess the decision is made.  I appreciate the help.  Larry

Larry