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As Diana points out your logic is flawed.Quote:
Originally Posted by solmanic
I have lost count of the number of toyota front ends which I have seen which have needed to be rebuilt because the diff bearings have been brinneled/rattled to death (i.e. are now indented/pitted beyond use) or the top half of the crownwheel has gone rusty. So your front end parts are likely to need replacing more often if you don't lock your hubs in enough.
Reading these replies and driving the vehicle with my hubs engaged / disengaged - I'm leaving them engaged now. Thanks for everyone's input. :)
I understand what you're saying but in all the years I owned and drove the Series III I never came across anyone espousing the virtues of leaving the hubs locked permanently in. I am not at all suggesting they remain permanently unlocked as your post above pretty much explains just how bad that can be. But in relation to your query about friction and wear the logic I am referring to is:Quote:
Originally Posted by Lotz-A-Landies
1. A moving part will wear faster than a non-moving part. We seem to disagree about whether moving via jiggling in a fixed orientation is ultimately worse than high speed constant rotation (plus jiggling).
2. It is easier to spin a wheel with the hub unlocked than one with it locked no matter how well the front axle & diff assembly is lubricated.
Surely to question the use of free-wheeling hubs at all is to question their fitment as standard equipment on nearly every part-time 4WD vehicle over the last 30 years.
I repeat my original assessment - Scallops - I don't think it really matters either way for the miles Matilda is likely to be travelling.
I guess there are always going to be idiots who buy Toyotas and then never take them off-road. :p (or never learn how to use them correctly).Quote:
Originally Posted by isuzurover
If a moving part is (a) under no load and (b) well lubricated, it will not necessarily wear.Quote:
Originally Posted by solmanic
I never noticed a difference in spinning wheels with hubs locked or unlocked.
Most/all other 4x4s beside land rovers have heavy grease lubrucating their swivel balls. Which results in lots more resistance to rotation.
However in the same vein, leaf springs are still standard fitment many nissotas, but coils are much cheaper to make, lighter, and give a smoother ride???
Solmanic
I'm not having a go at you, but I feel that a lot of the theories you espouse are the result of advertising myths and not engineering data. More than that I once thought about freewheeling hubs as you seem to now but after having had them on my vehicles from the mid 1970's onwards, I now believe that the disadvantages of freewheeling hubs far outweigh any benefits.
Quote:
Originally Posted by solmanic
Well actually, with the exception of off road, you did suggest exactly that!Quote:
Originally Posted by solmanic
As Ben confirmed the bearings in the uni-joints, diff pinion and carrier bearings become brinnelled (pitted in channels where the roller sits) causing premature failure, which doesn't happen with a rotating drive train that isn't under load. While minimal wear does occur it is spread evenly around the bearing not in trenches caused by the vibration in the one spot for the static drive train.Quote:
Originally Posted by solmanic
I believe that jiggling in the one plane is far worse than sliding during rotation. The reason for this is that in the static shaft the wear is in one plane, the splines can become quite sloppy in that plane but remain tight in the plane at 90 degrees to it. The wear in a spinning shaft is evenly distributed 360 deg around the spline.Quote:
Originally Posted by solmanic
You are talking about resistance to rotational forces, yes that is true during the initial acceleration. However once the drivetrain is in motion (a rotating mass) it will tend to stay in motion unless some other force acts upon it. This is born out by the lack of evidence of significantly improved fuel economy with freewheeling hubs disengaged.Quote:
Originally Posted by solmanic
Land Rover never fitted freewheel hubs to it's vehicles and for the last 25 years Land Rovers and many other makes have been constant 4WD. But it is true as a result of market pressure many car dealers (including Land Rover dealer networks in Australia-for about 10 years) offered aftermarket freewheel hubs as optional extras and the Japanese manufacturers even went so far as to make them standard equipment for private buyers in many markets.Quote:
Originally Posted by solmanic
I think we are all missing the point here. We are not talking about pristine bearing and gear surfaces that need to be protected to get us through the next 50 years.
Dan's vehicle has not had the driveline touched in the resto, so who knows what uneven or even wear has occured. Given the fact the vehicle is occasionally driven, I would leave them locked to lubricate the upper bushes, joints, bearings and such. If on the occasion you are going to partake in a drive of some distance(say to Blinman) unlock them. You will probably notice less vibrations more than anything else.
CC
Actually no... what I didn't include in that comment was that I was off-roading about once a month. Ergo I was locking in the hubs each month.Quote:
Originally Posted by Lotz-A-Landies
I'm not disputing this will happen if some peanut never engages their hubs, only questioning the idea the hubs should never be disengaged or that there is no benefit in disengaging hubs.Quote:
Originally Posted by Lotz-A-Landies
This is physics 101. More moving parts no matter how well lubed will have a higher rolling resistance than less moving parts. And I thought there was a wealth of evidence that they improved economy. I just Googled this out of curiosity and got no hits suggesting otherwise.Quote:
Originally Posted by Lotz-A-Landies
I said part-time 4WDs. As far as I am aware the standard fitment of free-wheeling hubs to Japanese 4WDs accounts for the majority. Incidentally, what part-time 4WDs have been marketed without free-wheeling hubs since, say 1980? This is a genuine question as I can't think of any.Quote:
Originally Posted by Lotz-A-Landies
There seems to be two furphys about free wheeling hubs:
1. That they reduce wear on the front axle. Quite clearly they do not, as Diana has pointed out and as Ben says, brinelling of bearings will occur. When new assembled cars were shipped to Australia from Britain, they were often found to have damaged wheel bearings from the vibration of the sea voyage! The advice given in a previous post to disengage them for long drives, seems to me to be the time which will promote maximum damage to the prop shaft; bearings and railko bushes.
2. That they promote fuel economy. In my experience of driving a Land Loser with hubs engaged, or disengaged over hundreds of kilometres along the same routes, there is no difference discernible at all in the fuel consumed.
In addition to the above; having the useless things disengaged when you desperately need 4WD in a hurry, such as when approaching boggy ground, or deep sand on a track, either leads to a tedious halt or an unexpected bogging. Many fire services for this reason weld or fasten the free wheel hubs in the locked position, after losing lives whilst a bogged vehicle is burnt-over.
MMmmm. People get fixated on a point of view and that's all they see.
Lets look at it this way. I have a series 3 that is used in much the same way as Scallop's Matilda. It is a car that is not a daily driver. It sits around all week, and if there is something on, and I have an oportunity, I take it out for a drive. Sometimes longer. The hubs get locked in for putting around town to lubricate everything after it has been sitting.
Now this is a 32yo car. It has been around a while, so while in excellent mechanical condition, and this is the important bit, "for it's age", it still has some foibles. So while hooning down the M1 at 110kph, the hubs are most definately unlocked, because it is much smoother with a whole lot less vibration through the steering and vehicle than when locked in. Now I hear you say, there must be something wrong with the driveline. Yep there is. It's been going around for 32 years. I could spend the money replacing every part and balancing the front shaft, but I would rather spend that money getting one of my other 14 vehicles finished. There is nothing actually wrong with the front driveline, it just has vibrations.
I also use this vehicle to tow my field kitchen of 1.6ton. I manouvere the trailer in low range, because it is easier. Without disconnecting hubs fitted, my manouvering on bitumen and concrete would cause all manor of wind up.
Now being a sensible person, if I go anywhere near away from the bitumen, which face it is all 90% of restored series 1's see nowadays anyway, I engage the hubs, or have on the way there to warm the oil and lubricate in preperation for applying driving force, and initiate 4wd.
Take the defender day out. I drove the 100 odd Freeway/highwayK's from my house to Boonah because it was more comfortable, engaged hubs at Boonah to prepare for off roading some 20k down the road. Went hard off road dragging the KFM in 1st low (just) up some Very steep hills, then disengaged for the 120 odd highway/freeway trip home.
You know what. The world didn't end.
If I drive it to Corowa, on the Highway, they will be disengaged, because it is more comfortable.Especially on the Billiard Table smooth modern freeways we have now. On dirt, there is that much else going on, locking them in you don't notice.
The wear compared to the previous 32 years of it's life in my opinion will be insignificant. I'm not for or against. I haven't fitted them, nor do I remove them. I just use a bit of practicality.
CC