The Ford Barn

skidmarks · 04-20-2020, 03:28 PM

Short of taking it apart or couting the rotation, anyone familiar with this stamping ? Just the number "7". Clear as day and no other numbers.

( yes, i know the usual 3 or 4 digits they usually have)

It is out of a bone stock 1948 ford convertible and i assume a early 48 it had lever action brakes.

rotorwrench · 04-20-2020, 04:47 PM

Is there anything on the bottom? If that is the bottom, disregard or check on top. The usually have two number sets that indicate the pinion and ring tooth counts. There are always exceptions though. The tooth count won't lie. Just divide one from the other on a calculator.

It may have been stamped on a Friday or a Monday.

JSeery · 04-20-2020, 04:50 PM

Just counting the ring gear teeth might give you a good idea.

skidmarks · 04-20-2020, 05:16 PM

Nothing but 7 . Was avoiding taking it completely apart.

Phil Gillespie · 04-20-2020, 05:38 PM

Quote:

Originally Posted by skidmarks

Nothing but 7 . Was avoiding taking it completely apart.

Just to take out oil filler plug and oil drain plug.
Can then mark a tooth and rotate and count.
Phil NZ

JSeery · 04-20-2020, 05:38 PM

Sponsored Links (Register now to hide all advertisements)

Just take the fill plug out, mark the ring gear. Then slowly turn it over and count the teeth.

Update: What Phil said.

JSeery · 04-20-2020, 05:42 PM

Quote:

Originally Posted by skidmarks

Nothing but 7 . Was avoiding taking it completely apart.

If you take care to turn both wheels at the same time/rate you can count the revelations of the driveshaft. Make the wheels and the driveshaft, rotate the wheels one revaluation and count how many revaluations the driveshaft turns.

You can also use the method where you hold one wheel and turn one. Believe there was a video on this method. Think it was Mart.

skidmarks · 04-20-2020, 06:42 PM

Quote:

Originally Posted by rotorwrench

It may have been stamped on a Friday or a Monday.

This is probably the answer to the NUMBER 7 .

'36 5W · 04-21-2020, 10:59 AM

As I recall, most were 3.78, at least those w/o o/d.

deuce lover · 04-21-2020, 11:03 AM

Probably 9-37 = 4.11

bobH · 04-21-2020, 01:54 PM

The 'usual' possibilities... 39-11, 34-9, and 37-9. I'm with Sheldon, as the only 7 is in 37-9. This from memory, so you might want to double check me.
'Course, counting is a more positive approach to knowing the ratio. See post 3 and 5.
And, another way (which I used myself, for my own 47), remove the plugs (to more easily turn the engine), put the trans in 'high' (3rd), jack up one rear wheel, turn the crank and count turns for TWO full rev's of the jacked up wheel.
OOOPS... I re-looked at the original post... put a vise-grip on the d/s, and count the turns.

04-20-2020, 04:47 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,425	Re: 1948 ford rear ratio Is there anything on the bottom? If that is the bottom, disregard or check on top. The usually have two number sets that indicate the pinion and ring tooth counts. There are always exceptions though. The tooth count won't lie. Just divide one from the other on a calculator. It may have been stamped on a Friday or a Monday.

04-20-2020, 04:50 PM	#3
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 1948 ford rear ratio Just counting the ring gear teeth might give you a good idea.

04-20-2020, 05:16 PM	#4
skidmarks Senior Member Join Date: Aug 2010 Location: newark, delaware Posts: 3,735	Re: 1948 ford rear ratio Nothing but 7 . Was avoiding taking it completely apart.

04-20-2020, 05:38 PM	#6
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 1948 ford rear ratio Sponsored Links (Register now to hide all advertisements) Just take the fill plug out, mark the ring gear. Then slowly turn it over and count the teeth. Update: What Phil said.

04-21-2020, 10:59 AM	#9
'36 5W Senior Member Join Date: Aug 2010 Location: Vancouver, Wa. Posts: 193	Re: 1948 ford rear ratio As I recall, most were 3.78, at least those w/o o/d.

04-21-2020, 11:03 AM	#10
deuce lover Senior Member Join Date: May 2010 Location: Southern France Posts: 5,301	Re: 1948 ford rear ratio Probably 9-37 = 4.11

04-21-2020, 01:54 PM	#11
bobH Senior Member Join Date: May 2010 Location: so cal, placerville, vegas Posts: 1,394	Re: 1948 ford rear ratio The 'usual' possibilities... 39-11, 34-9, and 37-9. I'm with Sheldon, as the only 7 is in 37-9. This from memory, so you might want to double check me. 'Course, counting is a more positive approach to knowing the ratio. See post 3 and 5. And, another way (which I used myself, for my own 47), remove the plugs (to more easily turn the engine), put the trans in 'high' (3rd), jack up one rear wheel, turn the crank and count turns for TWO full rev's of the jacked up wheel. OOOPS... I re-looked at the original post... put a vise-grip on the d/s, and count the turns.