Driving the Overdrive in gear all the time??

[msmaron]

I have a touring engine with 21+K on it, ,drive almost daily and as a rule shift into overdrive at about 40-45 mph and continue up to about 55-60.....I'm wondering if it would affect the engine at all leaving it in overdrive all the time,. I have a mitchell with is as they call it a "gear splitter" ., Any thoughts from anyone?


mark

[TerryH]

Mark
Not sure which OD you have, but with the Mitchell at 26%, I have left it in OD several times, and driven it around town. It does make all the gears taller, so you won't have to shift so quickly in each gear, but it will also effect your acceleration somewhat. I personally prefer to just use the OD normally, but I doubt there is a problem, as long as you do not lug it in any of the gears. Some of the other OD's are as much as 33%, and that would likely be too tall for normal driving.

[msmaron]

Originally Posted by TerryH

Mark
Not sure which OD you have, but with the Mitchell at 26%, I have left it in OD several times, and driven it around town. It does make all the gears taller, so you won't have to shift so quickly in each gear, but it will also effect your acceleration somewhat. I personally prefer to just use the OD normally, but I doubt there is a problem, as long as you do not lug it in any of the gears. Some of the other OD's are as much as 33%, and that would likely be too tall for normal driving.

Terry I have found the exact same thing... my acceleration is slowed down in 1st and 2nd but other than that noting else..thanks

[BRENT in 10-uh-C]

Doesn't hurt a thing on a Mitchell other than acceleration.

Ironically your final ratio is much higher than compared to the 3.27 ratio which some guys complain their engine won't pull the 3.27 ratio. When you figure the 3.78 ring & pinion with 26% (the amount of the overdrive) removed from that ratio, it puts you at around 2.8 final ratio. Makes you wonder doesn't it???

[msmaron]

Originally Posted by BRENT in 10-uh-C

Doesn't hurt a thing on a Mitchell other than acceleration.

Makes you wonder doesn't it???

Very interesting statement...it does and thank you

[CarlG]

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Originally Posted by msmaron

I have a touring engine with 21+K on it, ,drive almost daily and as a rule shift into overdrive at about 40-45 mph and continue up to about 55-60.....I'm wondering if it would affect the engine at all leaving it in overdrive all the time,. I have a mitchell with is as they call it a "gear splitter" ., Any thoughts from anyone?


mark

One of the reasons why I opted for the F150 4-Speed OD.

[modelAtony]

Originally Posted by msmaron

I have a touring engine with 21+K on it, ,drive almost daily and as a rule shift into overdrive at about 40-45 mph and continue up to about 55-60.....I'm wondering if it would affect the engine at all leaving it in overdrive all the time,. I have a mitchell with is as they call it a "gear splitter" ., Any thoughts from anyone?


mark

I have been running Mitchell and 3:27 gears since around 2001 in 31 Tudor. My engine has 5.9 Brum, Brierley cam, and Web carb. It pulls really good in all overdrive gears , I can leave it in overdrive all time , it's easy on the engine probably because of the extra uuuummmmph I have . Dyno is at 65 hp. I don't think you would have trouble in overdrive all time, Just pay attention to your car how it pulls. Have fun modelAtony tony white Lafayette, LA

[Bruce of MN]

Brent, I get a final ratio of 3.00 when I divide 3.78 by 1.26.

[Al Mack]

Originally Posted by Bruce of MN

Brent, I get a final ratio of 3.00 when I divide 3.78 by 1.26.

Brent's got it right.

When you're not driving in overdrive producing a 3.78 final ratio, you only have 74% of this number if the increase is 26%; therefore.....
Multiply 3.78 x .74 = 2.8

[Big hammer]

Not having an overdrive :-( IMO would not listening to your motor,trans,od be the thing to do? Each and ever situation be different? Happy motor Happy life :-)

[Jim Brierley]

You would have to slip the clutch a little to get moving, so it would wear more than normal. I personally enjoy shifting.

[Gyrodoc]

I wouldn't recommend starting in first over unless I had 4:11 gears and then maybe not even then. I find second over handy when driving in traffic around town. When cruising I shift about 40 or 45. I'm please with the Mitchell.

[Dave in MN]

Mark,
Even though your engine is well broken in, the concern I would have if you engaged the overdrive all the time is "lugging" the engine. I have a 26% Mitchell and standard rear end. (Love it!) If I am driving into a strong head wind or climbing a long incline, I drop out of overdrive. I typically only use overdrive when I reach road speed and want to decrease the engine rpm and noise.
I rebuild engines and the one thing I make sure I say three times to any of my customers is: Don't lug the engine. I make a point of mentioning to them that I am saying it three times so they remember the importance of: Don't lug the engine.
Need I say it the third time? Don't lug the engine.
Good Day!

[msmaron]

Thanks everyone,,,just was curios as to what people thought... I never do keep it in overdrive all the time but thought it was an interesting topic to discuss.,. Thanks for the insight and hope to see many of you in Niagara..