I have stock '49 Merc rear end questions

I agreed to trade one useless lump of iron for one slightly less useless lump of iron. I'm trading an air-cooled Ford-O-matic for a stock '49 Mercury rear end that's was gone through a year ago.

I was thinking that it would a quick and easy thing to stick behind the 223/3sp I got from Zor in a "A" frame, 27T body. Light car + weak engine = no broken rear end.

I searched and couldn't find anything that would answer these two questions, so here goes.

My question is what ratios were available in 1949 for the Mercury and is it any stronger than a like-era Ford rear?

Thanks in advance,
Mike

 

3.92, and 4.27 for the overdrive.

 

3.92 for a stocker... gonna take stove's word for the OD unit...

that said, them things were set up for a 60 to a hunnert horse motor, so i realy dont see a problem with a 110 horse 223, even if its been blessed and baptised giving it mebby, what... 150hp?

 

It might be too ugly for a modified.

I was thinking it could be a bolt-in in my 52 Ford too, stock '87 Town car 5.0L with and AOD, torque is right around 200. Anybody got any thoughts on whether or not it would be better than the stock '52 rear?

 

Picked it up yesterday, brand new brake drums, still has the e-brake cable, was going to used it under my '52...but when I saw it, I remembered that Mercury's up till '51 have the 5x5.5" bolt pattern, not good for the 52, but it is good for the back burner modified, no need for the adapters I bought (5x4.5" to 5x5.5"), I know some were looking for them.

...so there are differences in 49-54 Ford and Mercury rears.

 

Not sure about the Mercs, but the Fords of the era had a couple different styles of rear axle.

The p***enger cars - cept for the station wagons - ran a removable diff punkin similar to a 9" Ford. A very weak rear end although a lot of guys do ok just cruising around with them.

The wagons have a ****er rear axle which is easily ID'd by a removable sheet metal cover on the back of the diff.
Swapping gears in these is considerably more difficult than doing the drop in bit with the standard p*** car rear axle.

These ****er rear ends - w/4.27 gears in the overdrive cars - worked well for drag racing.
Installed on a 3000# car with hard slicks and the standard Traction Master setup used back in the day, they could handle ET's to the low 13's and into the 12's.
On a very lightweight car - Anglia's with SBC etc, they ran into the tens ok.

They are a direct bolt-in from wagons to the standard p*** cars and the width is correct.
Brakes are 11" as compared to the standard p*** cars 10" brakes.
The hot setup was to get the 11" front brakes from the wagons as well.
Made for a good drum brake setup on the 49-54 standard p*** cars.
53 on down - and maybe the 54's as well - were a direct bolt on from the Kingpins out.
Qualifying the 54 comment - since the 54's had a different style front end - their drums & hubs would probably work in the 53 & down cars.

 

The 49 to 51 Merc rear is fords version of a Dana 44. So any ring and pinion that fits a dana 44 will work. Only thing to watch is ring gear bolt size, the later ones are different. The differential side gears are Ford/Merc only. Strange as it may seem, outside of the spring perches, it is identical to a 48 to 53 F1 rear

 

The standard 51 Merc had 115 hp. I haven't broken my axle with 200hp SBC, so you should be ok!

 

I think same rear was used for Merc, F-1, and Ford station wagon/sedan delivery. That means p***enger pattern axles exist but are rare.

 

The 49 to early 50 merc rearend is a Dana 41 and there is very little parts for those. The late 50 to 51 mercs had a Dana 44, lots of parts for those rearends. I just had my late 50 merc rearend rebuild and re-geared to a 3:54.

 

I used a 52 ford station wagon rear end in my duece tub with shortened, resplined truck axles for the 5.5 bolt pattern. those ****er housings are the same narrow width as 57-58 9" axles so it fit under early fords. That was long ago when you could get those parts so might be better to go to something else.

 

The weak part of these Rear ends are the yoke. not much beef to it at all.

 

I ran a 50 merc rear in a 2,800 lb.drag car with 327 SBC and never had any axel problems.There tough old rear ends but I cant tell you how much HP they will hold before breakage. I estimate from 250-300 hp on our old rig and thats close based on MPH and rpm figures by todays math standards. There are many stronger units out there today you could choose from so its just a decision you will have to make.