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Aaron
23rd August 2014, 07:14 PM
Hey guys,

Im looking at putting ATB's front and rear (possibly a Detroit rear depending on what mood Im in)

Though its said with ATB's you don't need to upgrade axles I think its best practice to do so.

I plan on getting Ashcroft axles front and rear, CV's and drive flanges front and rear.

Would their heavy duty R&P's be the next weak point or worthy of a replacement?

If its not worth upgrading (this will be a touring vehicle only) Would there be much difference in money replacing them with new LR ones while they're out anyway?

Looking at their site I don't understand "reverse cutting". Is this an advantage? Also as for the ratio's. Is there not an option to retain the factory ratios?

(07 2.4 110 - 140km)

Cammo
25th August 2014, 08:21 AM
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.

redrovertdi
25th August 2014, 09:45 AM
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

workingonit
25th August 2014, 10:02 AM
If you have salisbury then ignore my comments. If rover diffs (my Disco), then I opted for Ashcroft lockers front and rear, and got rid of centre diff by replacing with ATB unit. Got hd axles, cvs and flanges. Still considering the reverse cut crown for the front.