hello everyone new member here. I have a 1950 merc I have put a sbford with c4 trans. I was under the assumption this car had a 4.27 ratio as it had overdrive. So I have been trying to find other options as it seemed from what ive read changing ratios in these rearends is problematic. After a couple days of measuring everything I had and going to junk yards I was getting frustrated, so I turned the pinion a little over 2 times and the wheel turned once. I don't know history of car it was last licenced in 1975 so maybe od wasn't functional and ratio changed back in the day. Am I wrong or isn't this a tall ratio for this car? I did have my son watching wheel turn so might be a little off. thanks for any comments, hayhog
Not the best way to check. Use accurate marks, and turn one tire exactly two turns, while counting pinion turns. The other wheel needs to be not moving. Example: Lets say it is a 3.00 to 1 ratio. Then two turns of one tire would make the pinion turn exactly 3 turns. However by using your method, it still seems like the ratio is low 4.00's I'm sure some of the Merc guys on hamb, know a good donor rear to use.
Those old Mercs. used a Dana 44 rear axle and are pretty tough . Originally there was a tag bolted on the rear cover but you might want to pull said cover to count the R & P to know for sure . Back n the day, I ran 324 Olds motors in those cars without breaking the rear.
Actually, it is a Spicer (now Dana) model 41, looks like a 44 but isn't. As for the ratio, when you turn the pinion and only one wheel rotates, you get a 'false' reading because of the effect of the spider gears in the differential. This happens if one axle/drum is 'stuck' or more difficult to turn than the other. You only get 'half' the turns of the actual ratio. So, double what you counted and that's your answer. The foregoing IS NOT applicable to posi-trac rear ends as they will not turn only one wheel. Ray
So has anyone figured out where to get different gears, or what to put in? I am looking into buying a fifty three, but it only does 55/60 @3000rpm. Hoping to get the rooms lower at high speeds. Posted using the Full Custom H.A.M.B. App!
The Dana 41 was dropped by Ford in '56 when they switched to the 9", so finding gears will be difficult. They weren't used in all cars either; in Ford cars, only the wagons, T-birds and police versions got them. And most ratios were in the high 3s/low 4s range in any case. If budget is a concern, some of the Ford Explorer rears will have mid-3s gears, or if you can find one, a 8" out of a 70s Maverick/Comet/Granada/Monarch should work. None of these will be a direct bolt-in.
How about a 9" rear from a 76' Bronco? A friend of mine has one he is willing to give me. Posted using the Full Custom H.A.M.B. App!
79 is too new on the F100's. needs to be 72 and earlier. These 9's are 1/4" wider Than stock and you'll have to flip the perches.
This is just the info I was looking for! I am wanting to do the same thing on a 1953 Monterey. Posted using the Full Custom H.A.M.B. App!
I recently put an 8.8 out of an 98 Exploror in my Merc. They have disk brakes, fit really well, pretty cheap at $130 I think, and there are a ton of them to choose from at the pull a part so you can get a lower milage axle and sort of judge the car on how well it might have been treated. I cut off all the stock stuff and welded on spring pads where I needed them to land. If your able to do that its a good option. The attached pic is a list of axle ratios to help decode rear ends when walking the yard. The data plate is on inside the driver door. I went with an the open 3.55 for my nailhead and 700r4. It runs about 2200rpm at 70-75 on the freeway. Hope it helps.
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