overdrive on or off?

[richard_5112360]

im going to be towing with our 3.7 jeep cherokee and would like to here from anyone else who has any experience of the same.i would also like for someones veiw on towing with the overdrive turned on or off! would it be better in 2wd or 4wd mode. any help would be greatfull. thanks.

 

[Lutz]

Overdrive??? Are you sure it's got overdrive? I haven't heard of a car with an overdrive unit for probably 30 years. I thought they went defunct when the first five speed gearboxes came on the market.

 

[Lol1]

I think you will find that this is an auto gearbox, Lutz. The gearbox in my American motorhome is auto, with the top gear being described as an overdrive. It probably isn't though, just as likely being the top gear, which is capable of being locked out.

Richard, you should be able to tow with your overdrive on, but if you are faced with some demanding roads such as those that pass through mountains it might be better to lock it out. If the jeep can run in 2wd and traction isn't an issue, everything should be fine. Check with your hand book though as a couple of 4x4 manufacturers advise using 4x4 when towing.

 

[richard_5112360]

yes your right,its an auto,theres a button on the side of the gear leaver.this model has the overdrive permenantly on and is turned off with the button.

 

[cris_408518]

We had the same on Volvo's some years back. Volvo suggested that you may need to lock it in 3 when towing to prevent it hunting between the top gears. The 2 ltr petrol car had no problems and we only ever did it twice.

 

[Guest]

Cris is right. My last Volvo 940 had a 3 speed auto with an overdrive 4th. Volvo recommended switching off the overdrive when towing because the system operates by electric solenoids, and when towing the more frequent changes could cause problems.

I towed with the Volvo through out Europe very happily, my only grumble being the fuel consumption was just averaging 19 mpg. It was manufactured in 1991 so Lutz has lost track of time a little bit with his 30 years, but that is allowed.

 

[DavidW1]

Richard,

Iam familiar with an overdrive auto in a 4x4, on Shogun and Bighorn. Use O/D and learn to switch it out just before the box wants to change down, that way you don't have a massive downshift through two gears and maintain momentum up those long motorway inclines without the engine screaming it's head off. Also switch it out in alpine or excessively hilly bits where you may find the box hunting between gears.

For towing in 4wd or 2wd drive consult your hand book - for example the older Mitsis are ok in 2wd but the modern ones specify 4wd for towing - something to do with the electronic load share I think. Your Jeep hand book or the manufacturer will specify>

 

[Lutz]

Cris is right. My last Volvo 940 had a 3 speed auto with an overdrive 4th. Volvo recommended switching off the overdrive when towing because the system operates by electric solenoids, and when towing the more frequent changes could cause problems.

I towed with the Volvo through out Europe very happily, my only grumble being the fuel consumption was just averaging 19 mpg. It was manufactured in 1991 so Lutz has lost track of time a little bit with his 30 years, but that is allowed.

I was thinking of the Laycock de Normanville units which were available as a factory-fitted option by a number of car manufacturers (Jaguar, Austin-Healey, Volvo, Triumph, to name a few). These were bolted on to the back of a manual gearbox.