3.54 rear gear in 46 to 48 convertible
 

Is anyone using a 3.54 rear gear in a 46 to 48 convertible? Is this car to heavy for this gear? Like to hear any Pro or cons. The car has a 4.11 installed in now ..... Thanks

Re: 3.54 rear gear in 46 to 48 convertible
 

to start with it would be helpful if you would go back and update your profile, mostly as to what city and state your in, in calif ,might be a little high for states that have a lot of mountains, Nevada or any states that are mostly flat that gear will be alright, hiway or city driving your good, so let us know where your at and then we can give a little more exact advice, 4:11 gears are usually found in over drive cars

Re: 3.54 rear gear in 46 to 48 convertible
 

Probably the best assessment was by Tom McCahill in an original road test...this link I found on here has excerpts: http://auto.howstuffworks.com/1941-1...er-deluxe8.htm
I have the original magazine somewhere. He was mostly a Ford fan in his views, and a year or two later than this wrote up an article on having the 239 in his own '49 or '50 Ford rebuilt by Granatelli...making it faster than the '49-'50 Cadillacs he had tested for only a few hundred dollars.

Re: 3.54 rear gear in 46 to 48 convertible
 

im maybe mistaken but didn't 46-48 mercs come with 3. 54 rear and 15" tires

Re: 3.54 rear gear in 46 to 48 convertible
 

I run a 355 15 inch tires with a5 speed love it

Re: 3.54 rear gear in 46 to 48 convertible
 

3.54 gears were standard in most 46 Fords.

Re: 3.54 rear gear in 46 to 48 convertible
 

Re: 3.54 rear gear in 46 to 48 convertible
 

For whatever it's worth, wife & I have a 46-48 convert (47F), and it came with 3.54's. In my opinion, it's a slug to drive, sluggish off the line, won't keep up on freeway on-ramps. Once going, it's ok. And, at freeway speed, it sounds 'busy', and I would like a taller gear. So, this is a 'non-answer'. I'd like taller highway gears, and lower stop-sign gears. IE, I'd like 3.78's and an overdrive. Or, maybe just a T-5 or similar. JMO

Re: 3.54 rear gear in 46 to 48 convertible
 

I have 3.54 gears in my `35 cabriolet with 16" wheels and it seems to be a perfect set up for me here in the hill country of West Virginia. The engine is a stock 21 stud and I can run 70 on Interstate. But I am sure my car weighs less than yours.

Re: 3.54 rear gear in 46 to 48 convertible
 

This is why FoMoCo went to the Borg Warner electric overdrive in 1949. Lincolns had been using them for years and they were really good for town driving just using 2nd gear & 2nd/OD for putting around town. You only needed to clutch at the stop signs. Most used the 3.92:1 gearing or there abouts. Mountain driving was better with 4.11:1.

3.78:1 has always proven to be the best overall gearing for cars with no overdrive or Columbia 2-speed axles.

Re: 3.54 rear gear in 46 to 48 convertible
 

My 46 Coupe has 3.54 and with the 16 inch wheels, it is an excellent cruiser on the freeway.

Re: 3.54 rear gear in 46 to 48 convertible
 

I agree 100%!!!!
The 3:78 is in my opinion the best "overall" gear set for your car. Gets the car rolling "off the line" with little effort and can be driven without stress on the engine up to 65MPH or so. No doubt as fast as prudent with a 1946 designed brake system.
The 3:54? Unless you live on a flat plain, forget it. The car is simply not powerful enough to get it rolling along well.
Yep, the 3:78... go for it. You'll be pleased!

Re: 3.54 rear gear in 46 to 48 convertible
 

AGREE X2. My '46 convertible has 3:78 and it is the best all around gearing for town & country driving.

Re: 3.54 rear gear in 46 to 48 convertible
 

Thanks for all the replys ..... I updated my profile ... Bruce , the Tom McCahill road test is a good read on the difference ... appears the 3.54 may not be the best overall choice for this car as those who have it indicate a slug off the line ..... those with 3.78 appear to like the better overall performance ... I do have a set of 3.78 gears I could install , so I will do that. Down the road if I find a columbia or Lloyd Young overdrive the 3.78 will work with them as well. I thought about the Mitchell OD but do not want to cut the floor for clearance .....

Re: 3.54 rear gear in 46 to 48 convertible
 

I have 354 in my 35 Pickup and my 40 Ford. They are super. I run 55 with ease and I live in the mountain area. They are no problem.

Re: 3.54 rear gear in 46 to 48 convertible
 

We have a Mitchell in our 46 four dour and no floor mods required. Not sure on your convertible. Have the cable shift as the lever shift would involve cross member changes. Love it.
John

Re: 3.54 rear gear in 46 to 48 convertible
 

One way to get a wider range of gearing (easy off the line but decent cruising speed) without going to a 5 speed or over drive would be to use a set of pickup gears (29 tooth cluster) with a "high speed" rear. Wouldn't be a hot performance combination, but it should make everyday driving pleasant. IMHO!

Re: 3.54 rear gear in 46 to 48 convertible
 

flathead 47 if you can find a volvo overdrive unit you can pick one up quite resonably. i had several of them and the most expensive one was 350 bucks. the unit is quite small and there has been some articles on here on how to put one in a torque tube. no levers they are electric solenoid. go real well with a 393 gear

Re: 3.54 rear gear in 46 to 48 convertible
 

The 29 tooth cluster and 3.54s would get you going, and drop the r's on the highway as recommended by PETEVS. Anyone have some real experience with that combination ?

Re: 3.54 rear gear in 46 to 48 convertible
 

my 46 coupe with headers and duals and merc crank has 3.54 gears and a columbia and i love it. i live in southern wisc.

Re: 3.54 rear gear in 46 to 48 convertible
 

Another vote for the 3.78 over the 3.54. My stock '47 Merc has 3.78 gears and is peppy around town and 'torquey' enough over 45 mph to climb the hills, foothills and mountains here in central and western NC, not only to hold speed but accelerate up most hills when necessary. Were the (vast) bulk of the driving done on midwestern flat lands or the flat Piedmont and coastal areas here in NC the 3.54 might be preferred. Ideal set-up is 3.78 with a Columbia overdrive unit to be able to comfortably set interstate paces (if needed) while keeping rpms around 2,200 in OD. In the meantime, while capability currently exists to run 70 mph with this stock set-up, am comfortable running 60 mph max to preserve the car and keep motor compartment noise associated with higher rpms minimized.

Re: 3.54 rear gear in 46 to 48 convertible
 

If you look at vehicle weight the post war Fords were considerably heavier than pre war versions.Combine that with a high diff and the extra power of the bigger motor was more than sucked up.We had a '46 Mercury with a 3.54 diff and although a good cruising car it just didn't have it on the hills compared to a '37 or '38 on 3.78 gears.I always felt it would have been better on 3.78.Cheers