Posted By |
Discussion Topic:
Rear end ratio?
-- page:
1
2
|
|
thirtysixford |
02-11-2018 @ 10:56 AM
|
|
|
Member
Posts: 210
Joined: Oct 2009
|
My '36 had a .444 gear in it. Took off like a banshee But the engine/fan noise was awful above 50mph
|
JM |
02-10-2018 @ 6:38 PM
|
|
|
Senior
Posts: 823
Joined: Oct 2009
|
I can usually determine rear gear ratio by draining gear oil in the rear, removing the gear oil filler plug on back of banjo housing, and counting the number of teeth on the ring gear. Then knowing the ring and pinion gear combinations typically used in production for the year and model vehicle being checked, you can determine the rear gear ratio. This method has always worked well for me, and is the quickest/easiest method in my opinion.
John
|
1934 Ford |
02-03-2018 @ 6:44 PM
|
|
|
Senior
Posts: 574
Joined: Oct 2009
|
The 9 34 stamped in the rearend housing means 9 teeth on the pinion gear and 34 on the ring gear. Divide the 9 into the 34 = 3.777778, which means you have a 3.78 gear. If it says 9 37 (37 divided by 9= 4.11111) or called a 4.11 First number is turns of the pinion gear, second number is turns of the ring gear or axle. The lower the number the faster the top speed, the higher the number the quicker acceleration.
1934 Ford's since 1972
|
woodiewagon46 |
02-02-2018 @ 7:55 AM
|
|
|
Senior
Posts: 704
Joined: Nov 2012
|
Frank, brings up a good point. Perhaps the rear end was rebuilt at some time and the stamped "two" is a mark of who the mechanic was that worked on the rear.
|
ibshane |
02-02-2018 @ 7:31 AM
|
|
|
New Member
Posts: 147
Joined: Oct 2017
|
I agree. Mine seems shorter than 3.78 when driving it.
This message was edited by ibshane on 2-2-18 @ 7:34 AM
|
FrankM-RG5 |
02-02-2018 @ 7:20 AM
|
|
|
New Member
Posts: 135
Joined: Oct 2009
|
They just stamp the number of teeth on each gear. The earlier answer about turning the engine is more correct because over the years who knows what went into these.
|
ford38v8 |
01-31-2018 @ 11:55 PM
|
|
|
Senior
Posts: 2765
Joined: Oct 2009
|
C'me on, Shane, don't you remember your father's answer: "To make little boys ask questions." Sheesh.
Alan
|
ibshane |
01-31-2018 @ 9:02 PM
|
|
|
New Member
Posts: 147
Joined: Oct 2017
|
Why wouldn't they just stamp 3:78?
|
40cpe |
01-31-2018 @ 6:17 PM
|
|
|
Member
Posts: 476
Joined: Jan 2010
|
34/9=3.7777 (3.78) I don't know what the 2 is.
|
ibshane |
01-31-2018 @ 2:40 PM
|
|
|
New Member
Posts: 147
Joined: Oct 2017
|
This is the only numbers I could see stamped into the diff. housing. Looks more like it would be a date? 9 - 3 4 2
|