Topic: High pinion in rear?

[guywithuglyyota]

I was wondering if there would be any oiling issues if you were to use a high pinion toyota housing in the rear. The truck is a daily driver. Reason why i ask is because im pretty sure toyota only offered the high pinion in the front of land cruisers, not the rear. Were they keeping cost down, or is there a specific reason this is not more common? (besides cost)  Thanks in advance

[jr9162]

There are potential issues with proper lubrication. More importantly you'd be driving forward by applying torque to the weaker coast side of the gear set.

Unless you need a high pinion in the rear for serious rock climbing and/or racing, namely where you don't mind spending a sponsor's money on broken parts, just stick the high pinion diff with reverse cut gear set in the front  - where it belongs - and a low pinion in the rear. That way neither diff will be running on the weaker coast side of the gear set.

[Marlin]

When a high pinion is installed in the rear, due to the design, the ring gear will actually be throwing the oil away from the pinion.
This will tend to starve the pinion bearings, especially the smaller, front bearing.

When i ran one the the rear of my truck, I took a fill plug and drilled a 1/4" hole in the middle of it and then installed the plug in the fill thread of a bent housing. By using a hole saw, i was able to cut out the 18x1.50 mm seat and then welded it in the top of the rear end housing.

After filling the rear end to the factory fill hole, I removed the top plug and added an additional pint more.

Dean, my salesman, is running high pinions front and rear on his 85 truck.

Marlin

[guywithuglyyota [OP]]

Thanks for the info JR and Marlin, Im glad you cleared up that issue, seems to be a problem with other axles however I was not sure with Toyota units. I will stick with high pinion front and standard rear. And I will be visiting your shop soon Marlin to pick up a few goodies such as a new tranny, duel ultimate and two arb thirds, I hope you dont mind walk ins.

Luke

PS: I got orders to Alaska so I will definately need lockers!

[jr9162]

Man u coming up from Edwards AFB to Anchorage eh? When?

You'll have to stop by and see me when u get up. That's where I've been since 11/87. U driving up or flying and shipping the truck?

Send me an e-mail and we can chew the fat a bit....

[Freakshow]

When a high pinion is installed in the rear, due to the design, the ring gear will actually be throwing the oil away from the pinion.
This will tend to starve the pinion bearings, especially the smaller, front bearing.

When i ran one the the rear of my truck, I took a fill plug and drilled a 1/4" hole in the middle of it and then installed the plug in the fill thread of a bent housing. By using a hole saw, i was able to cut out the 18x1.50 mm seat and then welded it in the top of the rear end housing.

After filling the rear end to the factory fill hole, I removed the top plug and added an additional pint more.

Dean, my salesman, is running high pinions front and rear on his 85 truck.


Marlin

So how long did your salesman's gears last? Have there been any updates on running a high pinion in the rear? Would you sell a housing with the modifications that you made?