Thread: Puma rear P38 diff lock

Originally Posted by wagoo

Not convinced that a reverse cut ring and pinion for the front would be a positive upgrade. The idea is based on a false premise IMO.
Certainly the standard ring and pinion up front does drive on the coast side of the teeth when driving forward, and generally the coast side only 70% as strong as the drive side, but due to weight transfer when accellerating,climbing or towing, the front diff rarely sees the same torque loadings as a rear diff does. The majority of scenarios where the front diff gets high torque loads is when reversing up steep banks or out of a hole or recovering a stuck vehicle in reverse .In these scenarios the standard ring and pinion will be loading the stronger 'drive side' of the teeth, whereas the reverse cut ring and pinion will be driving on the weaker 'coast side'.
That has been the experience of Toyota 78, 80 and 100 series vehicles.
Bill.

All true Bill, but as I see it the main reason for using a high pinion front diff in a coil sprung verhicle is to obtain clearance for a rear mounted tie rod (for Ackerman steering).

Nissan used proper size ring and pinion for their high pinion front diff, Toyota simply did not, plus Toyota compounded the problem by using a crush sleeve between pinion bearings, then bloating the vehicles.