Diff Output Shaft Spline Play

[david.g.chapman]

I still have the original diff output shafts on my +2, from 1970. They are the earlier type.
There is a fair amount of spline wear and spline play which you can feel when driving the car.

I am thinking of replacing them for new forged items, but am unsure as to what it would do to the play. Is the wear shared equally between the diff splined hole and the output shaft or does the shaft wear more?

Dave Chapman.

[512BB]

'There is a fair amount of spline wear and spline play which you can feel when driving the car'

How do you know it is spline play when driving the car? Could it not be backlash or indeed play anywhere in the driveline, including the gearbox?

If you take a rear wheel off and have a play, you maybe able to narrow it down.

Leslie

[david.g.chapman]

The point is well made, as how can you tell where the play actually is?

All I can say is that there is physical wear on the output shaft splines, and that as you rotate the output shaft you can feel play, then internal contact in the diff, then further play, then the propshaft starts to move.

Dave Chapman.

[ncm]

[quote="
All I can say is that there is physical wear on the output shaft splines, and that as you rotate the output shaft you can feel play, then internal contact in the diff, then further play, then the propshaft starts to move.[/quote]

From your description the first play that you feel could well be between the sun and planet gears , the further play then being between the crownwheel and pinion.
The only way you will be able to check for play between the output shaft and its gear is to remove the diff from the back casing and then reinsert the shaft into its gear.

Brian.

[david.g.chapman]

Thanks for both of your replies.

I've just thought of a way without taking the diff out.

Measure the angle of play from the ears of the output shaft to when the propshaft turns.
Remove output shaft.
Make up a wooden output shaft from a length of wooden dowel with a tapered end and a cross piece of the same diameter as the ears on the output shaft.
Jam the tapered end into the diff gear to eliminate spline play and measure the angle of play at the cross piece.
Compare the two angles of play.

I'll give it a try this winter!

Cheers,

Dave Chapman.

[512BB]

Unless you have examined the output shaft splines and can phisically see wear on the splines, which I doubt, I think you are wasting your time, and will be wasting your money on new items.

Many of you have one of my rebuilt diffs in your car. When I was pulling them apart and rebuilding them, 40 + units, I do not recall seeing a single one where I thought 'those splines look and feel worn out'. Yes, there were a few with twisted splines, but worn, no.

Original output shafts were not made of chinese pot metal. They were made of incredibly hard English steel of whatever grade, I am no steel expert, but just try filing one. So my offer to you Dave is, if you are going to Malcolm's do on Saturday, I can lend you a nos shaft, or close, and you can compare it to what you have. If you are not going, I am sure someone can transport it closer to Writtle for you to collect. I am thinking Sir Wilkes, but that would have to be arranged.

Please advise if you would like to take me up on my kind offer

Leslie

[david.g.chapman]

Thanks for chiming in Leslie! From your not inconsiderable knowledge of our differentials, I'm going to pass on your kind offer.

I have taken the output shafts out before and have noticed some marking on the splines. They have travelled about 183000 miles. However, even if there is some play I'm not going to gain very much with new shafts, and my weedy Federal twin cam has not succeeded in twisting anything!

So I'll leave it until I find something else to do!

Dave.