Why Manual Hub

[ra_01]

Hi can you please help me understand why manual hub is better than auto. My car is not a daily drive but a tourer. I do travel quite a bit; Trying to enjoy Africa as much as possible. However, I don't do much rock crawling, unless I encounter a situation during a trip.

For me the auto hub is very convenient. I don't have to get out of the car and switch the front wheel hub to lock and then engage 4h. I understand that with manual we can engage 2h to 4h while driving provided the hub is locked. But other than this are there any other advantages.

Reason for asking this question is, recently I watched Ronny Dhal's video and he is raving about manual hub, while Patrols had them since early 2000. I have not heard anyone complaining about auto hub failures, except some of them have intentionally gone for manual.

Should I stick to the current set up or change the hubs to manual?

[Steele]

From a touring perspective, we had a situation where the manual hubs were preferred. We were in Lesotho and towing heavy trailers. When descending one of the very steep and long tarred mountain passes, the vehicles with manual hubs were able to select low range 2wd. This helped them maximize engine braking on the descent without cooking their brakes. The vehicles with auto hubs had to use high range and a couple of them struggled with their brakes. Also going up the passes, low range could be used as the naturally aspirated engines lose about 25% of their power at that altitude.

[Alex Roux]

- Manual hub allows you to go 2x4 in low range. I.e. without the front wheels being driven.
It is a slight advantage in slow traffic on tarmac, saves the clutch a bit if you move very slowly.
With auto locking hubs you cannot do this unless you are on dirt roads, since then you can damage the drive train.

- It is good practice to get the transfer case and front diff spinning every now and then. Circulation and change in temps ensures seals don't go hard.
With auto locking hubs you cannot do this unless you are on dirt roads (as above).

- There are after market manual locking hubs that are much stronger that stock manual or auto locking hubs (even when set to locked as opposed to auto locked).

[Peter Connan]

The manual hubs are stronger, but the auto hubs are strong enough for the usage described.
The Patrol auto hubs also have a "manually locked" position, and when this is engag3d you can also select 4-wheel drive "on the fly".

Other than that, the major advantage as already mentioned is the ability to use low rsnge 2-wheel drive. I find this very handy when reversing a trailer and use it often in slow traffic.

[ra_01]

From a touring perspective, we had a situation where the manual hubs were preferred. We were in Lesotho and towing heavy trailers. When descending one of the very steep and long tarred mountain passes, the vehicles with manual hubs were able to select low range 2wd. This helped them maximize engine braking on the descent without cooking their brakes. The vehicles with auto hubs had to use high range and a couple of them struggled with their brakes. Also going up the passes, low range could be used as the naturally aspirated engines lose about 25% of their power at that altitude.

I was in Lesotho myself last year, and I had to use 4L with triptronic set to 3rd gear max (was shifting between 1, 2, and 3 depending on the speed) for getting down on those very steep mountains as breaks were getting hot. All of this while hub was in auto. But once I was done, had to go back to 2H and reverse a bit for the hub to disengage properly.

So with manual hub we can shift from 2H to 4L on the fly even though the hub is set to manual? This is handy.

[Peter Connan]

So with manual hub we can shift from 2H to 4L on the fly even though the hub is set to manual? This is handy.

There is no Manual setting on the manual hubs. Only Lock and Free. With manual hubs locked, you can shift to 4H at any sane speed, providing you are not spinning wheels.
With manual hubs on free, you have to be stationary or nearly so to shift the transfer case, but of course you won't actually be in 4-wheel drive.

With the auto hubs manually locked, you can shift to 4H at any sane speed, provided you are not spinning wheels (same as manual hubs locked).

I believe you are supposed to be able to shift to 4H with auto hubs on auto at very low speeds (and assuming again that no wheels are spinning), but I wouldn't recommend it unless in a serious emergency.

Just to add, driving with the hubs locked does no damage even for extended periods and in fact the owner's manual asks that you lock the hubs for short periods every month, as the bearings in the axles only get oil if the shafts and gears are spinning, but are subject to vibration whenever the vehicle is driven.

When I go on a trip, I usually lock the hubs the moment I turn onto dirt road for the first time, and leave them like that untill I turn back onto tar for the last time. I've even had my best-ever fuel consumption with the hubs locked.

[ra_01]

Thanks Peter, good to know that fuel consumption will not get affected when locked. What's the maximum speed do you think one can do with hubs are locked? Sometimes in on and off situation we may drive on tar.
Ya I have actually started locking the auto hub recently so the bearings will get oiled. But this is only for a short period.

[Peter Connan]

What's the maximum speed do you think one can do with hubs are locked? Sometimes in on and off situation we may drive on tar.

Erm, you drive a 4.8 hey? What can they do? 180? 200?

Whatever it is, you can do it with the front hubs locked.

To be clear, the one advantage of un-locked hubs is supposed to be fuel consumption. That's why they are on the car, and if one tests very carefully, I am sure they will make a difference.
I just can't really see the difference. As stated, my best ever consumption was hubs locked. But it also happened to be a very long stretch of very level road (road from Kasane to Palapye) and I was going slower than normal due to other reasons (I had a ball joint that was busy dying, and going over 100 meant bad steering wobble).