merc diff

Alaska Jim

Alaska Jim

Well-known member
any one here ever rebuild a stock 49-51 merc diff, or a 49-54 ford wagon diff. that does not have the drop- out 3rd member? If so I would like communicate with them by private message, if possible. thanks.-----Jim
 
Yes , I have a shop manual, and I know how to do the work, and I have all the tools to do the job, I have been a automotive, heavy equip. and aircraft mechanic for the last 40 years. I am now retired. I was just wanting to ask a few questions about some of the items shown in the shop manual exploded view,just want to " pick a few brains" of some one who has rebuilt one of these specific diff's, not differentials in general. Thanks.---Jim
 
On the same page since these rear ends are Dana 44's , what years are compatible with each other? I have a ring and pinion from a 70's dodge that is Dana will it work in my 50 mercury?
 
As far as parts interchanging it would be nice if you have a "friend" at your local Auto wreckers so you could check out his Hollander manuals.
 
I have never done a 49 Merc style, but I have done an 8.8 out of a Ranger pickup. Same design. I found it very easy to work on. I had a chunk of scrap angle iron about 4 1/2 feet long. I drilled two holes in it to bolt on the flange in front, to hold while I loosened the yoke nut. Everything else will be read and do for a guy with your experience.
 
I have all the parts needed to rebuild the diff, except a "wick" . it is shown in the factory 1951 Lincoln/Mercury shop manual in the exploded view. part # is 8m4673. I have checked with all of the aftermarket suppliers, C & G, Joblot ,Mac's, Carpenters, Van Pelt sales, obsolete ford, streamline, vintage auto parts, etc., etc.. I did find a listing at Green Sales, and ordered a few. well, I think they must have their parts in the wrong bin as the "wick" seems to be made of some type of felt material, and what they sent me is clearly the "deflector that goes on the pinion shaft flange that bolts up to the drive shaft. and is metal. I looked at some dana 44 pictures, but this part is not shown. I have cked with axle rebuilders and none seem to know anything about this. the one that came out of my car can not be used again as it is torn. I guess my main question is , is this really needed, or can I get by with out it. It looks to only be there to help with oil control at the pinion seal, and does not have any affect on pinion depth settings or bearing pre load. any thought, suggestions, or possible sources or solutions? all are welcome and appreciated. Thanks------Jim
 
Ole Don, I used a 1/2 " impact to take the flange nut off, but will be fabricating a "handle" to hold the flange when I re-install the nut and am setting the torque with a torque wrench. thanks for the suggestion.-----Jim
 
Bounder, I don't know if they would work. the ring and pinion gears in my car are good, just have a bad pinion bearing. going to replace all the bearing, including axle bearing's since it is completely torn down, then I wont have to worry when the next 60 year old bearing is going to fail. I have had my 51 Merc. since 1994 and don't have any plans to sell it. although some days I think a change to something else would be nice. it is then that I start working on my flathead powered 29 roadster again.
 
Alaska Jim I'm putting a 351 in mine and of course have to get rid of the stock 393 or what ever it is, and I found a free 272 ring gear and pinion. Seems to have the same bolt pattern but won't know till I tear the old one down. That's why I was asking.
 
Bounder, I am pretty sure these Merc diff's are Dana 41"s not 44's so not sure if the gears are interchangeable. The factory gearing in my 51 merc. is 4:27 to 1. the car is an overdrive car. I think that a 272:1 would be to high of a ratio. I would suggest nothing higher than a 325:1. If your Merc does not have overdrive, but is a stick shift, your factory rear ratio could be anything from about a 390:1 to 454:1( or something in that neighborhood). Automatic cars ,I think had some thing like 331:1 or something close to that. If you gear to high with a stick shift you may end up having to "slip" the clutch a little more than you would like due to the weight of the car. you also may find that you are "lugging" the car on steep hills and having to downshift more than you should. on the other hand top speed will be way, way up there.
 
I don't to want to hijack this, just add some background.

FWIW if you go to http://www.kaiserwillys.com/category/3181, you'll find some common parts for the 41/44 Dana's, but not the gear sets, near as I can tell. Back in the late 60's, I put a dana 44 from a 6 cyl ford wagon, 427:1, in my 55 bird. The whole works was the same, except for the spring perches. The automatic ratio was 3.31. Most o/d V8's were 4:11. I don't remember what the non o/d cars were. So, I suspect Dana used a lot of similar gear ratios to satisfy Ford. The best info on Dana's comes from the willys/jeep sites, as they used them for years. You need to check the axle and bearing sizes, as they varied. My 55 bird has a truck axle, which was not stock, and must have been replaced somewhere over the years.
 
Mines a dana 44 392, the car had a three speed without od. With a 392 rear end and a 60 over 351, cam, 4 barrel, and a C 6 ******, I'm afraid I'll be geared to low so I was looking for something else and this guy gave me the 272 gear set. It may not even fit but the price was right. If it don't fit, I'll just add it to the pile of other useless stuff I've bought for this engine switch. Oh Well. Thanks for the help, though. Any more ideas I'm listening, can't do anything else with 6" of snow and the car is 20 miles away. I ain't like the Blues Brothers anymore .
 
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To the best of my knowledge the Wick (Driving Pin Oil Seal) sits next to the Oil Slinger and has no importance to setting the Pinion depth. If that is your question. I believe that with no Wick (as with no slinger) you may get some oil leaks.
 

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my main concern was the possibilities of oil seepage, and the necessity of using it because of the lack of availability, not any pinion depth, rotating torque, shimming, or other concerns. thanks for your answer. I appreciate it. ----Jim
 
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