Posted By |
Discussion Topic:
1951 Rearend Ratio
-- page:
1
2
|
|
Mercman |
03-11-2010 @ 8:08 AM
|
|
|
Member
Posts: 6
Joined: Oct 2009
|
Thanks for your helpful comments. I guess I'll just give in and do the "axle transplant".
|
JebNY |
03-06-2010 @ 3:45 PM
|
|
|
Member
Posts: 44
Joined: Nov 2009
|
I had an 1950 F5 with 2 speed axle and it worked out nice for a road driving, BUT. It was a very heavy axle assembly and it had a much larger wheel/tire size than the smaller model F1-3. The larger tire diameter was important since the axel was 5:14/5:83, not much help with pickup tires.
Jim... 1950 F1 Stake
|
supereal |
03-06-2010 @ 9:39 AM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
I agree with 37. I've never heard of an axle transplant being a factor in inspection, but I don't know about Canadian laws. It has been common for many years to have different rear axles in trucks. Some due to the variance between vendors, special orders, or junkyard repairs. As you have already replaced the "widow maker" split ring rims, it seems odd the type of rear axle would be a factor. I've never seen a pickup with a two speed axle, as the largest are the "tonners", and the two speeds were installed in the ton and a half and larger.
|
37RAGTOPMAN |
03-05-2010 @ 1:23 PM
|
|
|
Senior
Posts: 1965
Joined: Oct 2009
|
some of the old trucks had a 2 speed rear axle,this also a option, if you can find one, a friend of mine had a roll back truck with a 2 speed rear and it travel down the road with no problems, I doubt that the law would know the difference,if you were stopped,not unless it gets inspected,and I highly doubt they would know the difference also. my 3 cents,37RAGTOPMAN
|
Mercman |
03-05-2010 @ 12:00 PM
|
|
|
Member
Posts: 6
Joined: Oct 2009
|
I have a '51 Mercury M3 pickup with the original 255 ci flathead coupled to the original 4-speed low geared straight-geared (no synchro) tranny fitted with a Power Take-off unit (PTO). The original wheels are huge 8-bolt 17" split rims which I've had to replace for '66 Mercury 8-bolt 16" rims for safety's sake. (No one will touch split rims anymore). Plus, it lowers the truck a bit. First gear is what I call "bull-low" for pulling extraordinary loads up steep hills. The truck used to be owned by a wrecking yard and had a 15-foot long A-frame with a huge mechanical winch on it. When I first bought the truck in 1982,I used it for hauling and lifting massive fir trees (16" dia by 100'long) for a log house building project. I've since restored the old girl and made a complete 8'-long pickup box for it. It's great, except for the really low gearing...probably that 4:27 ratio someone mentioned. I never use first gear except to demonstrate how it will only go 5mph with it! I have Canadian Collector Licence Plates on it, which essentially means that I cannot make a drivetrain change to a modern axle for the benefit of economy and highway speeds. I'm wondering if anybody knows of a way to change the original gearing (axle or fourth gear) to achieve highway speeds (60-70 mph), without the very expensive overdrive solution. For example, is there a replacement pinion one can acquire?
This message was edited by Mercman on 3-5-10 @ 12:07 PM
|
supereal |
03-05-2010 @ 8:37 AM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
Many of us grew up with the old "crash boxes", and I still find myself "double clutching" now and then. It's true that overdrive units are not cheap, but given the rather narrow power band of the flathead engines, they do provide the means to travel safely at today's highway speeds when necessary without a screaming engine. My Ryan OD cost just over two grand about ten years ago, and has been trouble free, to date. For anyone considering such an installation, be sure that your steering and brakes are capable of safe operation at speeds above 50-55 mph. These cars were not designed for the 65-70 mph common today, and any handling deficiencies can produce disaster quickly.
|
37RAGTOPMAN |
03-04-2010 @ 5:08 AM
|
|
|
Senior
Posts: 1965
Joined: Oct 2009
|
yes that is the ideal combo, IF you have the $2,000-$3,000 for the MITCH OVERDRIVE UNIT, I thought that the only gear in a 4 speed that was not a snycro was 1st, but that 1st does come in handy if you have a use for it,and it depends how much you drive the car or truck to go the extra $,for many different upgrades, I never had a problem shifting them, and then there are the 5 and 6 speed trans out there that could be installed as well just my 3 cents worth,37RAGTOPMAN
|
supereal |
03-03-2010 @ 2:19 PM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
Most of the four speed transmissions were non-synchro, and offer few advantages, unless you plan to do some stump pulling. The ideal combination is a 3-78 rear with a 30% add-on overdrive, such as the Mitch*ll. It allows you to run a hiway speeds, yet retain plenty of power for traffic driving. I don't shift into OD much below 40-45, but I can run 65-70 when needed to keep up with traffic and not have some jerk trying to push me.
|
37RAGTOPMAN |
03-03-2010 @ 6:55 AM
|
|
|
Senior
Posts: 1965
Joined: Oct 2009
|
HI Caretaker Higher ratio [411-1] lower speed more power for steep hills and pulling loads lower ratio [ 354-1 ] higher speed on highways and less power on steep hills and you have to use lower gear in trans for steep hills, this is the way I understand it, I put a 354-1 in my 37 Cabriolet, and goes faster on the road, gets better gas miliage,and I really do not see any or much difference on hills, using the 85 hp engine, my 3 cents worth 37RAGTOPMAN IF YOU have a 4 speed with a granny gear you will have sort of the best of both worlds.if you had a high speed rear,low ratio 355 378 and like If you plan on carrying loads or pulling a trailer go with a 378 or so
|
supereal |
02-19-2010 @ 2:21 PM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
A low ratio would be 1-1, a higher ratio would be 1-2, etc, low referring to the result of dividing the number of teeth on the ring gear by those on the pinion. Thus a high ratio, 9-37, results in a gearing of 4-12 to 1, while a low ratio, such as 11-39, produces 3-55. I think the confusion results from the usual "high gearing" to "low gearing" useage, rather than the numerical ratio. A 3-55 gearing results in more turns of the axle per drive shaft revolution, and higher speed before you run out of revs.
|