1991 F53/E4OD gearing?

[SteveLevin]

(at least, I think it's the E4OD.. the 3 speed plus overdrive with the 460)

Does anyone know the gearing relative to speed and engine rpm? I've often wondered where 3rd (drive) at 55mph was really putting me rpm-wise, and my coach doesn't have a tach. It never seems like it's near redline (after all, I wouldn't expect the tranny to downshift into an over-rev) but I've always wondered exactly how many rpm that represents with regards to redline and max power, and I figured someone much smarter than me here would know!

Thanks!

Steve

[subford]

In 3rd the transmission is out of the picture as it is running at 1 to 1 ratio.
You would need to know what the rear end gear ratio is and the size and manufacturer of the rear tires. You can got to the tire manufacturers web site to find out how many revolutions per mile your tire does.

Then knowing the rear end gear ratio you can find out the RPM's at any speed in 3rd gear.
You can get this information off a tag on the rear end or from the sticker on the side of steering column. There is an axle code there that can be translated to the ratio.

The gear ratios of the E4OD Transmission:
1st = 2.71
2nd = 1.538
3rd = 1
4th = .712

Take mine for instance:
Mitchelin LT235/85R16/E = 654 Rev Per Mile or 32" tire height.
Rear End ratio: 5.13:1
At 55 MPH = 2963 RPM's

Engine RPM Calculator
http://www.csgnetwork.com/multirpmcalc.html

My axle code is 73:

[LVJ58]

If I recall correctly, I believe the rear end ratio is 5.16:1 on chassis with the 460 engine.

[RUNDLC]

My 96 HR f53 w/ 460 & auto tranny has 5.13 gears per my build sheet.