Manual Hubs - should I have them locked all the time

Well the front drive is not going to wear any more than the rear drive just from being driven without power, is it?

Hi Allan

Being a totally unmechanical female i can't outline it all. He explained all that was wearing and how much more it would cost us compared to turning the hubs off when not needed. I have to believe him.

Mh

If the gears, axles, unijoints and bearings are rotating they are wearing.

In fact there are types of wear that can only happen this way.

cheers

Hi Mh,

A farming wife being unmechanical? I don't believe it for a moment.
Well, maybe your mechanic is right. I was just applying simple logic...... very simple! LOL

I certainly now leave mine engaged in country where I might have need of 4WD in a hurry. Once ploughed through the sand to the barge at Inskip Point having forgotten to lock them. The barge operator was as surprised as I that I made it. And there have been other times too.......!

Thanks Bantam - just as he said. You're not my mechanic are you? LOL - He is a very good mechanic :)

Mh

Hi Motherhen and Allan,

If the drive is left engaged then it places strain on the drivetrain to the front and back wheels more so than normal due to diff windup.

With the front wheels disengaged this windup does not occur as it is not generated in the first instance.

This windup can be severe. I once broke the front left half axle in my 70HP 4WD tractor due to windup because I had the front drive engaged most of the time. They always let you down when you need them most. Certainly not the case any longer. It only gets selected when needed now and disengaged as soon as it is no longer needed.

The broken half axle was substantially larger and stronger than those found on a Toyota I can assure you so those stresses can be quite severe. Even if you do not break something then you are wearing something needlessly. So your mechanic was spot on Motherhen, if it is not needed disengage it for safety sake as one day your life may depend on it.

Alan,
you are right in the case of the constant 4WD but this is due to the centre diff. Anything with lockable freewheeling hubs is not so lucky as they cannot get rid of the windup unless unlocked or you drive backwards to relieve the stress buildup.
You can notice this buildup in our vehicle if you bring in 4wheel drive via the dash button and is more noticable in low range by our not being able to disengage low range to go to high range.

You probably know all this anyway Allan so if that is the case please excuse my lesson. It was offered with good intention.

Cheers, Bruce.

Thanks Bruce but simply locking the free-wheeling hubs without moving the drive selector to "4WD" does not engage the front drive to the gearbox, it is still isolated so no windup can occur. Perhaps you misunderstood some of what we were saying.

All that happens with the hubs locked is that the front wheels are now connected to the front drivetrain which is now simply idling along....spinning the components but transmitting no power and being ready to quickly engage 4WD.

Certainly, after operating in the 4WD mode and reaching firm ground it can be necessary to reverse a few metres to relieve the gear mesh and allow the 4WD to be disengaged.

Constant 4WD with a centre diff is a different matter but then they don't have lockable/freewheeling hubs so it is not an issue.

I'm sure Motherhen understands about the issues of transmission windup also.

Thank you Allan, I am on the same page now. LOL

I certainly can notice the difference when I fling it into 4WD-Low having forgotten to lock the hubs (see above)

But you are right of course about everything spinning and being smoother etc. There is always a penalty for convenience.

Thanks Peter, I was feeling rather alone on this.

Is it too late to remove your hub-locks?

Yes Wilko, I often use low range 4WD with unlocked hubs to move the boat and trailer around the yard without having to ride the clutch. Very handy.
I leave the hubs unlocked till it looks like I might need 4WD. If I haven't used 4WD for a month or so, I lock the hubs for a few km.
I once had an old (1964) Nissan and fitted lockable hubs to that. They were an innovation then.
Before that I had a 1959 ex army Series 2 Land Rover. No hubs. The front drive shaft spline and universals were forever needing attention.