Thread: Drive line weak points

Good talk on upgrading your axles.

Some would argue that your rear diff is the next weak point. Ashcroft develeoped and used to offer a HD diff centre in standard ratio (3.54?) You just needed to get your driveshaft shortened by ~30mm. Not sure if they still offer this.

The diff in the front of your truck is essentially an upside down rear diff. As im sure you've seen from photos, crownwheel and pinion teeth are helical (curved). One side is stronger than the other. Because your front diff is running "upside down", when travelling forward, the diff is driving on the weaker side of the teeth. Reverse cutting rectifies this, so when travelling forward, the diff drives on the strong side.

If your pulling your centres to fit ATBs, inspect your crownwheel and pinion sets. They might be alright. Im not going to buy into HD vs standard replacement in stock ratio, as I honestly haven't looked into it enough, except to say that many puma diff related problems seem to be set up related rather than component related, so if the bloke building them up for you this time knows what he is doing, as far as touring goes, you should be right.

If you have a salisbury rear? i fitted a detroit and ashcroft 1/2 shafts with HD flanges, although i never broke a rear 1/2 shaft the reason for replacement was worn splines with the Hd flanges in good shape, since fitting the ashcroft 1/2 shafts i have had to replace 1 HD flange as its splines wore, i have a trutrac in the front and broke a standard cv joint a few weeks ago[rough off roading- didnt know it was broken till i hit the tarseal and unlocked the centre diff], in fairness to the standard cv joint it was 470,000ks old.
Richard