Tow speed v revs??

[john]

Hi everyone just curious, I understand that you should not tow in 5th gear, (I have a D22 td3.0 and a 2.3 ton tandem caravan), however When towing the engine sits on aprox 2800 - 3000 rpm at 85 -90 kmh. My question is: Is 3000 rpm to high for me to sit on constantly during travels around Oz? Or should I consider dropping back to 80 kph and around 2600 rpm?
cheers John

 

[Leprechaun]

That's BS. If the 5th gear isn't strong enough to tow on, I'd buy another ute. 80k's around Oz would be too painful, for you and other road users.

 

[Jason]

Most people say not to tow in 5th because it's not the 1 to 1 ratio, produces too much axial thrust in the gearbox for long periods at high load. 4th is the 1 to 1 ratio.

I think the bearings on the 5th ratio are pretty small too? Someone will have to verify that though.

 

[Matt76]

I'd rather rebuild the gearbox after a few years than travel the highways at 80km/h. Boring and unsafe I believe.

 

[will]

to answer your question, 3000 rpm should be fine to sit on for long periods, you'll just use lots of fuel, especially with 2.3t on the back.

I sit on 3000rpm (115-120kph in 5th, 265/75 r16s) most of the time when doing outback / highway runs, get pretty crappy liters per 100 without towing.

 

[tweak'e]

Most people say not to tow in 5th because it's not the 1 to 1 ratio, produces too much axial thrust in the gearbox for long periods at high load. 4th is the 1 to 1 ratio.

I think the bearings on the 5th ratio are pretty small too? Someone will have to verify that though.

ratio dosn't mean jack.

the older models where known to have a weak 5th gear but the D22's are fine. just use 5th gear as per normal.

 

[Jason]

Yeah I know, just stating the methodology behind the practice.

 

[Old.Tony]

I prefer mine to be in top gear for towing. Even though mine's an auto, I still like to see it get into top (5th) so that fuel consumption drops.

If you're cruising, you're not really exerting a lot of force on the drive train, you're just maintaining the vehicle's forward speed. I can't see that being an issue in top gear at all.

 

[Jason]

I tow my CT in 5th all the time, it's obviously nowhere near the 2 1/2 T mark though.

 

[d40 abuser]

ya drop bac to 4th up hills and and overtaking cruising in 5th will be fine the fuel u will save will pay for a new box anyway

 

[Dave]

I tow in 5th, come to a hill drop back to 4th before you hit the hill.

If it drops under 90km/h in 5th drop back to 4th.

Thats what I do if I need to tow a loaded car trailer.

My gearbox is still good. No noises or crunching.

Dave.