Tranny Ratios???
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 294
Likes: 3
From: Northern New Mexico
Tranny Ratios???
Our 1998 Expedition came with H6 axles, E40D Tranny and 5.4L engine.
This tranny is a four speed "overdrive".
Does anyone know what the overdrive ratio is with the 3.73 axle?
Is third gear direct drive? If not what is the ratio?
I drive a lot of miles on steep grades at 7,500 to 9,200 feet with the tranny overdrive locked out and was wondering what the ratio is for that third gear.
I know squat about automatic trannys. Never had one before and will never have one again. So, if the gearing in this automatice is not analagous to a manual transmission with discreet ratios, please forgive my ignorance.
I did search the forum and found lots of useful information but not what I am asking now.
This tranny is a four speed "overdrive".
Does anyone know what the overdrive ratio is with the 3.73 axle?
Is third gear direct drive? If not what is the ratio?
I drive a lot of miles on steep grades at 7,500 to 9,200 feet with the tranny overdrive locked out and was wondering what the ratio is for that third gear.
I know squat about automatic trannys. Never had one before and will never have one again. So, if the gearing in this automatice is not analagous to a manual transmission with discreet ratios, please forgive my ignorance.
I did search the forum and found lots of useful information but not what I am asking now.
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 294
Likes: 3
From: Northern New Mexico
Thank you both! Now I don't feel so bad about leaving the Expedition in OD lockout (3rd) for the mountain grades knowing it is direct drive to a 3.73 diff ratio. Leaving it in 4th means kicking down to third about mid way and then down to second nearing the crest. This brings the RPM way up which is distracting to the driver and cannot be good for the engine since the tach needle is showing a big increase in revs. Begining the grade in third means staying in third all the way up and over which has to be easier on the engine.
