Most people I spoke to seem to agree that there should be some play between the needle bearing and the axle shaft. If too tight then damage may occur while in the 4x4 mode and turning or hitting a bump. Some trucks actually have a lot of play between the shaft and the differential. I know for sure that the older 4Runners did have such play.

Of course when everything is put together with a new hub lock this play is reduced greatly (but it is still there). As I said in my previous posting, I inserted a brand new axle end in the new hub bearing assembly and there was very little play - so at least when new the play is very little.

I will proceed putting everything back together and unless it becomes obvious that I need new axle ends, I will drive my truck without replacing the axle ends.

However, I am replacing everything else: Hub bearing assembly w/needle bearing, new yellow O-ring, all new thrust washers (3 + 1 ) new snap ring and new hub lock.

 

My stub axle has a lot of play up and down but the needle bearings and axle are in excellent condition.

 

The interesting thing is that the needle bearing is turning in relation to the axle stub when the hubs are UNLOCKED. So, under normal driving, that needle is seeing action all the time.

When the hubs are locked, the axle stub is not moving in relation to the needle bearing, the entire assembly turns all at the same time.

It might explain why it's built with so much play. Under load, it's all moving as a single unit.

 

I think that needle bearing just keeps the axle in line due to the single main hub bearing arrangement. That main inner hub bearing is a mystery because no one sees it. Does anyone know what it looks like? Is it a ball bearing or double roller bearing? Single roller bearing?