Overdrive question

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Apr 1, 2002 | 07:50 AM

Petrol

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Laughing Gas

Joined: Dec 2001

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From: Virginia

Overdrive question

Apr 11, 2002 | 10:19 PM

Rough Legged

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Overdrive question

I have a 4.2L 5 speed manual. My owners manual does not say anything regarding manual transmssions in refrence to towing in overdrive. Will I cause damage to the engine or transmission if I tow in overdrive. What kind of speed can I do in 4th gear without causeing any dammage. I do not have a tach. I will be towing a boat of approx. 2,200 lbs. loaded. I have the 3.55 axle and the vehicle is rated for not more than 3,500 lbs.

Thanks,
Len

Apr 12, 2002 | 10:55 AM

BrianA

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From: Trussville, Alabama

Overdrive question

I have the same engine / drive train you do. Pulling 2200 lbs should be no problem. I have pulled a heavier boat with no difficulties. Pulling at highway speeds in O/D should not be a problem. Just don't lug the engine (climbing steep hills, etc)
You can press the trip reset button in, hold it in while turning the key to "run" position, continue holdiing the button in until "test" is displayed, release the button, crank the truck and then press the reset button to scroll through until you reach a "digital tach" mode. This will stay in test mode until you turn off ignition.
For the record (if you have 255/70 16 tires) in O/D you have 32 RPM per mph. Example 70 mph x 32 rpm = 2240 RPM. Also, O/D has a ratio of .7:1 and 4th is 1:1. So, divide your RPM in in O/D by .7 and you get your RPMs in 4th.
Hope this help...
Brian A

Apr 12, 2002 | 10:59 AM

BrianA

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From: Trussville, Alabama

Overdrive question

oops, my bad....ratio in 4th is .8:1...not .7:1
Brian A

Apr 12, 2002 | 06:26 PM

Rough Legged

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Overdrive question

Thank you very much Brian. I'll give it the test this weekend.

Len

Apr 13, 2002 | 01:56 AM

TonyG

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Overdrive question

I have a '87 F350 with the 3.55 rear and ZF 5 speed. On the drivers visor is an ad'visory' (get it ad-visor-y) about not towing in overdrive. I still do it though.

The overdrive gear in the tranny is the smallest gear and might wear quicker with the extra stress. It depends alot on how much you tow and your speed.
If it starts pulling the motor down, you can use fourth. On highway cruising with no hills and not much load, be your own judge. But of course there must be a reason they advise against towing in overdrive.

Tony

Apr 15, 2002 | 12:27 PM

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From: Michigan

Overdrive question

Brian A.,

Where did you find the info about getting the test mode on the odometer - is it in the Ford service manual? I didn't know that you could do that, and since I also have a 5-speed with no tach it might come in pretty handy. I wish there was a way to get it to stay in tach mode all the time, as I really only need to know my miles when I'm checking gas mileage and I'd rather just have a tach readout there.

Now I'm going to have to play with my truck until I figure out what all the other test modes do.