Thread: PUMA - Drivetrain Upgrade

Drover,
Dumb question time, the new parts dont look too different, what is the upside of doing the change? Is it just that they are better quality and more reliable? Or will it fix a particular issue you have?

I am picking and choosing what upgrades to do and following the trends, call me a sheep!!

Just wondering what the advantage of them is really.

cheers
Pat.

Originally Posted by Drover

...

Thanks to Garry at English Auto Service at Tuggerah for his help and advice,

Good report there Drover.

Also good choice of adviser there as well - Garry is one of the best Land Rover mechanics about.

Originally Posted by patclan

Drover,
Dumb question time, the new parts dont look too different, what is the upside of doing the change? Is it just that they are better quality and more reliable? Or will it fix a particular issue you have?

I am picking and choosing what upgrades to do and following the trends, call me a sheep!!

Just wondering what the advantage of them is really.

cheers
Pat.

Pat,

Ashcroft axels and CV's are made from 4130 Alloy steel. Their CV’s are custom designed and their machine work is exceptional, the axels, drive flanges and CV's are known as the strongest items on the market, without question.

My wife and I intend to do a lot of touring and some will be in very remote places. A lot of the time we will be alone.

I am trying to make my PUMA as strong and reliable as possible. It will never be used as an extreme off roader, but places like the Simpson, Cape York and the Canning are all on a long list.

The last thing I want to do is to have to undertake repairs or wait for parts ETC on the side of some track in the middle of know where.

These up graded parts certainly fill a questionable void in the reliability of the drive line.

Cheers
Grant

I haven't kept myself completely up to date on axle shaft technology, but if Dave Ashcroft visits this thread, would he care to comment on the decision not to waste down the shaft diameter between the splined ends, to alllow the shaft to torsionally flex evenly over its entire length, instead of concentrating the torsional stress at the smaller cross sectional area of the splines? Have new material specifications and heat treatment techniques rendered this practice obsolete?
Would anyone else with relevant knowledge care to comment?
Wagoo.

Originally Posted by wagoo

I haven't kept myself completely up to date on axle shaft technology, but if Dave Ashcroft visits this thread, would he care to comment on the decision not to waste down the shaft diameter between the splined ends, to alllow the shaft to torsionally flex evenly over its entire length, instead of concentrating the torsional stress at the smaller cross sectional area of the splines? Have new material specifications and heat treatment techniques rendered this practice obsolete?
Would anyone else with relevant knowledge care to comment?
Wagoo.

Bill

This seems to be a very common practice in the U.S. now as well

Wayne

Originally Posted by LowRanger

Bill

This seems to be a very common practice in the U.S. now as well

Wayne

Wayne. What is now common practice? Wasting down or not doing so? To my knowledge most of the popular US shaft makers don't do it,probably for reasons of cost. But more engineeringly inclined outfits such as Daimler Benz for example, waste down the Unimog halfshafts.
They are so particular about itin fact that shorter shafts are wasted down more than the longer ones so that torsional flexibility is equal over all 4 shafts.
Wagoo.

Originally Posted by wagoo

Rick, with your trucks rear wheels having ''more toe in than your fronts'' longer splines, on more snug fitting MD shafts and drive flanges, do you find that your drive flange bolts regularly work loose?
Wagoo.

I had major problems on the canning with rear flange bolts working loose, however I think the problem was more down to the fact that I had maxi county flanges and halfshafts in a defender axle, and the PO hadn't increased the bolts length sufficiently to account for the spacer. I drilled and tapped the hubs to M12 and fitted longer bolts - no problems since.

Originally Posted by wagoo

I haven't kept myself completely up to date on axle shaft technology, but if Dave Ashcroft visits this thread, would he care to comment on the decision not to waste down the shaft diameter between the splined ends, to alllow the shaft to torsionally flex evenly over its entire length, instead of concentrating the torsional stress at the smaller cross sectional area of the splines? Have new material specifications and heat treatment techniques rendered this practice obsolete?
Would anyone else with relevant knowledge care to comment?
Wagoo.

Those axles appear to be waisted to the modulus of the spline cross section, rather than to the root diameter of the splines.

As far as my limited metallurgy/mechanics goes, this should ensure reasonably uniform stresses along the shaft.

However waisting to the root diameter of the splines would be preferable.

Originally Posted by isuzurover

Those axles appear to be waisted to the modulus of the spline cross section, rather than to the root diameter of the splines.

As far as my limited metallurgy/mechanics goes, this should ensure reasonably uniform stresses along the shaft.

However waisting to the root diameter of the splines would be preferable.

An engine reconditioning firm I once worked for, after every race meeting would receive the diff/axle components etc from a couple of V8 Supercar teams for crack testing. The shafts were also full floaters and splined both ends.
They were wasted down to well below the root diameters and polished to a mirror finish to eliminate potential stress risers.
Wagoo.

Oh no,got that De Ja Vue feeling again.Time to give it all away and pursue other interests.