.

 

is there a big difference between E40D and C6 in the end gearing?
is it easy changing gear ratio of either of these?

 

e4od is an over drive trans and c6 is not

 

...and neither the ratio nor the difficulty of changing the rear axle ratio has anything whatsoever with the transmission. Both trannies were offered with a variety of rear end ratios.

 

.

 

might have had something to do with the mpg gain or loss, or power gaine or loss. this would made a difference between the end gains of a rear axle swap...

 

Obviously, but that was not the question which you asked.

 

sorry for that didn't quiet exactly knew how to put what i ment.
it should have been more like
what difference the two make with the same and with different rear axle ratio.

 

The C6 has a 1:1 top gear so the overall top gear ratio is the final drive (i.e. rear axle) ratio. The E4OD has a 0.70:1 top gear ratio so the OTGR with various rear end ratios would be:

2.73 x 0.80 = 2.18
3.08 x 0.80 = 2.46
3.31 x 0.80 = 2.65
3.55 x 0.80 = 2.84
3.73 x 0.80 = 2.98
4.11 x 0.80 = 3.29

 

In other words: the truck will go faster with an E4OD, or it'll go the same speed at lower RPM. That's what the "OD" (OverDrive) means.

Automotive Terms & Abbreviations

SR
The ratio is actually .712, but why did you do all your calculations with .8 ?

 

Mazdog on the brain (or what passes for a brain)
I've got a lot of the gear ratio stuff spreadsheeted and I must have grabbed the wrong block.

2.73 x 0.71 = 1.94
3.08 x 0.71 = 2.19
3.31 x 0.71 = 2.35
3.55 x 0.71 = 2.52
3.73 x 0.71 = 2.64
4.11 x 0.71 = 2.92

 

I

I have the 1992 ford regular cab 4x4 with the 3.08 gear . In my opinion the 3.08 gear is an okay gear for off road . Im about to change mine from 3.08 to 3.55.

To your question 3.08 gear is ok for pulling trailers every once in a while . But not everday like me . Dont get me wrong but the 300.6 with 3.08 has a lot of torque but it starts lagging when you have 5,000lbs siting on it trying to pull up a hill . Thats where the 3.55 would come in handy.

3.08 gear is from 0 to 4,500 lbs
3.55 gear is from 0 to 6,500

3.08 is more of a highway gear not a pulling gear . You will break your transmission if you have to much weight but not enough power because your making transmission work over time pulling heavy loads.

 

Thread is 4 years old.......

 

Can any body tell me if yhis is a good idea i have a 1993 ford f150 5.0 2x4 an i get bad gas mileage my 3.55 gears are good but i drive on high way alot an i have a boat ut a small 15 ft bass an i run 75 at 2400 would like to drop it down about 2000 maby 2100 if posible

 

Gears do not significantly affect MPG, so no: it's not a good idea.

Your description of the truck is vague. Click this & read the caption:



What exactly is the truck's MPG? Is the speedo/odo accurate? What tire size is listed on the door sticker? What tire size is on the truck? What pressure are they at? What modifications & cargo does the truck have?



Take a few extra seconds to proofread your post & add punctuation. The easier it is for us to read, the more likely you'll get helpful replies.