PTO Overdrive Unit - Silly Question

[LandRoverRo]

Can the overdrive always be engaged when driving? Or is it only to be used after 4th gear is topped out?
TIA

[Tim Smith]

Not recommended but it can be done.

You didn't say what type it was... If it's a Fairey, then just don't do it. If it's a Roverdrive, well they claim you can do it but I wouldn't recommend it.

The only reason why is because you would be over stressing the overdrive unit and could be causing an early death to it by using it in the 1st and 2nd a lot. Too much torque in those gears.

Feel free to use it to split gears. I split 3rd all the time with my Roverdrive unit. I would be more hesitant to do that as often with the Fairey but maybe mine was just weak to begin with...

[LandRoverRo]

Not recommended but it can be done.

You didn't say what type it was... If it's a Fairey, then just don't do it. If it's a Roverdrive, well they claim you can do it but I wouldn't recommend it.

The only reason why is because you would be over stressing the overdrive unit and could be causing an early death to it by using it in the 1st and 2nd a lot. Too much torque in those gears.

Feel free to use it to split gears. I split 3rd all the time with my Roverdrive unit. I would be more hesitant to do that as often with the Fairey but maybe mine was just weak to begin with...

Great info. Thanks very much. I believe the unit is a Fairey so I'll try and baby it. It already whines quite a bit and sounds pretty nasty on overrun (ie just slightly off accelerator).

[Mercedesrover]

Great info. Thanks very much. I believe the unit is a Fairey so I'll try and baby it. It already whines quite a bit and sounds pretty nasty on overrun (ie just slightly off accelerator).

Yup, that's a Fairey!

I split with my Roverdrive all the time. 3rd, overdrive is a very helpful gear!

Hey Tim, how hot does you're Roverdrive run? Mine runs so hot you can't touch it. I just switched over to a mixture of 75W90 and 75W140 full synthetic in both the transfer case and gear box.

Jim

[Tim Smith]

Hey Tim, how hot does you're Roverdrive run? Mine runs so hot you can't touch it. I just switched over to a mixture of 75W90 and 75W140 full synthetic in both the transfer case and gear box.

Jim

Very very hot. How's that for specific.

On short runs there is no problem but if you are racking up millage on the freeway it'll heat up to the point that it's worrying. I think it's just the nature of these things.

I've switched to Lucas (85w-140?) oil in all my gear boxes and the noise reduction has been FANTASTIC! Now it's the tires and engine fan that make the most noise on highway runs... I think.

[Tim Smith]

Great info. Thanks very much. I believe the unit is a Fairey so I'll try and baby it. It already whines quite a bit and sounds pretty nasty on overrun (ie just slightly off accelerator).

NP, hope I'm right.

When was the last time you changed the oil in it? The fairey overdrives have a separate reservoir and it's only about a pint or two that it holds. Old dirty oil could be attacking it, leading to bearing wear which might explain the extra whining on overrun.

[LandRoverRo]

NP, hope I'm right.

When was the last time you changed the oil in it? The fairey overdrives have a separate reservoir and it's only about a pint or two that it holds. Old dirty oil could be attacking it, leading to bearing wear which might explain the extra whining on overrun.

I just picked the car up last Friday. The fluids were (seemingly) changed regularly, but I haven't checked the overdrive. I'll get on that this weekend. It seems like a fairly easy unit to remove for service. Is this so? I can see the drain plug, but is there a separate fill hole higher up?

[Tim Smith]

I just picked the car up last Friday. The fluids were (seemingly) changed regularly, but I haven't checked the overdrive. I'll get on that this weekend. It seems like a fairly easy unit to remove for service. Is this so? I can see the drain plug, but is there a separate fill hole higher up?

Uh... Yeah... I think it's easy to remove. And if you have the replacement input shaft gear (and cover plate) you can just pop it out and drive the thing while you service the overdrive at your leisure.

Filling it, uh... Can't remember where but there is a fill hole some where up there. You might find access to it much easier if you lift out the bottom of the middle seat.

Have fun with your new truck!

Cheers,
Tim

[Mercedesrover]

Very very hot. How's that for specific.

On short runs there is no problem but if you are racking up millage on the freeway it'll heat up to the point that it's worrying. I think it's just the nature of these things.

I've switched to Lucas (85w-140?) oil in all my gear boxes and the noise reduction has been FANTASTIC! Now it's the tires and engine fan that make the most noise on highway runs... I think.

I'm leaving on the 30th for a 3500-4000 mile trip to Northern Quebec. Is that long enough for it to get hot?

Thanks for the reply and I'm glad to hear about the noise reduction of the thicker oil. My gearbox is pretty noisy at 65-70mph and if I can reduce it by even half I'd be happy. But I know what you mean...The air rushing by these trucks at that speed is pretty loud!

jim

[KevinNY]

The fill and dipstick is on the top drivers side if the Fairey, Some have a knurled knob some a 13/16" bolt head.