High pinion diff

[h0nke]

I did a quick search and couldn't find it answered, but I know it must be on here somewhere so forgive me.....

What is the difference in high pinion diff v.s. your standard 4cyl diff  ? I was reading on doing a solid axle swap and they reccomend using a high pinion in front for better driveshaft angle?

As long as you have same gear ratio no problem with high pinion front and standard rear right?

And one more thing since we are on the topic, for the best power/economy trade off should I run 4.88 or 5.29 with 36x12.5x15 tsl swampers? I noticed in Petersen's that give-away 87 truck had 38" swampers with 4.88, wouldn't that be guttless?

Thanks guys  . I am trying to learn as much I as I can so when I do my SAS it will be no big deal.

--eric

[BigMike]

Hey h0nke, long time no see,

Check out this site: http://home.4x4wire.com/erik/diffs/

The High Pinion mounts the pinion above the center-line of the ring gear as apposed to slightly below it. Because of this, a reverse pattern gear set must be used with the High Pinion Diff.

The Benifits are that the pinion is up and away from rocks, and so is the drive shaft.

Definately an excellent upgrade choice

As far as I know, Marlin was the first person to discover that the High Pinion could be fitted to a modified Hilux housing, and at that time, he was running High Pinions in the front and rear of his rig. However, with the High Pinion mounted in the rear, the oil pump is now spun in the reverse direction, and the bearings will over heat.

So the High Pinion can only be safely used in the front, unless you are building a trail-only rig that wont see speeds over about 30 mph for any prolonged time periods.

BigMike

[h0nke]

Thanks Mike for the info.

Ya it's been awhile, went to Sacramento for 8 week horse shoing class.

I'm back now and as soon as I can sell my 73 Chevy I will be looking to buy a reg. cab ifs truck with a 22re. I am going to do the SAS on it.

How about them gears tho, should I run 4.88 or 5.29 with 36x12.5x15 tsl's?

--h0nke (eric)

[mudmaster]

I run 5.29 and can still pull 70 mph on flat ground only, run out of gerbils on hills. I've got 36x12.5x15 TSL (bias). 

[awhotrods]

I have 37" MTR's and 5:29's.  After the 22RE swap, I can run with anyone on the freeway and even pull hills in 5th gear.  I'm very proud of my little squirrels under the hood!

[h0nke]

Thanks for the replys guys

awhotrods - how difficult was the 22re swap? i could save me a lot of money with buying solid axle and swapping in a 22re, instead of doing SAS.

[h0nke]

oh ya almost forgot - awhotrods- the truck in your avatar kicks ass