OK, this is hardly ground breaking but you know that I like to add to the written knowledge bank from time to time.
It's not often that you have a whole front drive train sitting on the bench, so today with more bits that than I knew what to do with I had a play.
What surprised me was how much play there was in the whole thing - and where that play was. OK, it's been a while since mine rolled of the ploduction rine in Japan, but it's all in good condition with 70k on the clock. I know that we need some slip in there, don't get me wrong. I tried a variety of components to see if there were any parts that were more worn that others. 4 different shafts, drive flanges etc., You get the picture. However the diff is a JW and therefore beyond question. Barely a gnat's chuff of play. Not too much, not too little.
The first connection was the drive shaft into the diff. Noticeable play there in the splines. Next was the drive shaft into the CV. OK not new CVs but in good condition. Obviously a bit more rotational slop there. Then the outer CV shaft into the drive flange. This was the least of all. Pretty good actually. So when all assembled there was a few degrees in it. And all of this without moving the diff gears at all.
As usual, there isn't much point to this other than to say that when you rock your wheels looking for play, it's not really possible to tell what is in the diff and what is in the shafts to any accurate degree. BUT and here is the point, when you drive at an obstacle then wham it into reverse and hit the throttle there can be significant rotational slack to take up which is never going to come as a pleasant surprise to your shafts etc
Additionally, I was intrigued by the little bronze sleeves that sit in the stub axles. I tried making up the cv, hub and whatnot on the bench too and I originally thought that the CV would fit quite snugly in the bush - it doesn't. Not by any stretch of the imagination. The swivel is solid to the axle tube, the stub solid to the swivel, the hub solid on the stub via the bearings, but the shaft, CV and its shaft have some scope for movement. The front face of the CV near the ABS ring mates up against the bronze bush. So where does it get lubrication from? Not from the CV grease as it's immobile and not from the bearing grease. Now on my old truck the bush used to spin inside the stub axle. But on this one it's solid in the casting. Should they spin? When you torque the wheel bearings up with the big nut, the outer CV is pulled against the bronze bush to 'crush' the taper rollers in the hub. Seems as this would be a wear point and the reason why hub settings would change over time. Shouldn't there really be a bearing in the end of the stub to take the outer CV. Is this why they have changed the design and done just that? It's metal on metal in there. If you are confused or simply exasperated, I can take pics tomorrow.
So, am I missing something (again
) OK quick edit, of course the nuts DON'T pull the cv against the inside of the stub face, the threads are on the stub. So the axle floats about completely. No friction there. So even more slop then? The longer shaf surely has the potential for more 'whip' if you like. The inner axle oil seals must have a hard life.
That's it really.
Chris
It's not often that you have a whole front drive train sitting on the bench, so today with more bits that than I knew what to do with I had a play.
What surprised me was how much play there was in the whole thing - and where that play was. OK, it's been a while since mine rolled of the ploduction rine in Japan, but it's all in good condition with 70k on the clock. I know that we need some slip in there, don't get me wrong. I tried a variety of components to see if there were any parts that were more worn that others. 4 different shafts, drive flanges etc., You get the picture. However the diff is a JW and therefore beyond question. Barely a gnat's chuff of play. Not too much, not too little.
The first connection was the drive shaft into the diff. Noticeable play there in the splines. Next was the drive shaft into the CV. OK not new CVs but in good condition. Obviously a bit more rotational slop there. Then the outer CV shaft into the drive flange. This was the least of all. Pretty good actually. So when all assembled there was a few degrees in it. And all of this without moving the diff gears at all.
As usual, there isn't much point to this other than to say that when you rock your wheels looking for play, it's not really possible to tell what is in the diff and what is in the shafts to any accurate degree. BUT and here is the point, when you drive at an obstacle then wham it into reverse and hit the throttle there can be significant rotational slack to take up which is never going to come as a pleasant surprise to your shafts etc
Additionally, I was intrigued by the little bronze sleeves that sit in the stub axles. I tried making up the cv, hub and whatnot on the bench too and I originally thought that the CV would fit quite snugly in the bush - it doesn't. Not by any stretch of the imagination. The swivel is solid to the axle tube, the stub solid to the swivel, the hub solid on the stub via the bearings, but the shaft, CV and its shaft have some scope for movement. The front face of the CV near the ABS ring mates up against the bronze bush. So where does it get lubrication from? Not from the CV grease as it's immobile and not from the bearing grease. Now on my old truck the bush used to spin inside the stub axle. But on this one it's solid in the casting. Should they spin? When you torque the wheel bearings up with the big nut, the outer CV is pulled against the bronze bush to 'crush' the taper rollers in the hub. Seems as this would be a wear point and the reason why hub settings would change over time. Shouldn't there really be a bearing in the end of the stub to take the outer CV. Is this why they have changed the design and done just that? It's metal on metal in there. If you are confused or simply exasperated, I can take pics tomorrow.
So, am I missing something (again
) OK quick edit, of course the nuts DON'T pull the cv against the inside of the stub face, the threads are on the stub. So the axle floats about completely. No friction there. So even more slop then? The longer shaf surely has the potential for more 'whip' if you like. The inner axle oil seals must have a hard life.That's it really.
Chris
