Diggity

Alrigh, I've read a couple places that it is not recommend high pinion third members in rear axle applications. I don't understand why not. Also, I've heard that the high pinion setups are stronger. I don't understand that either. Anybody got any insight?

Thanks!

fillsrunner4

you starve the diff of gear oil, also i believe the setup and the way you drive forward can make it not as strong as you would think. im not 100% sure of that statment and one place you can read more on this is Marlins Forum. The thread i posted is long but he was running two high pinions and at some point in the thread he talks about it in great detail
http://board.marlincrawler.com/index.php?topic=6472.0
Awesome truck and amazing custom work. one of my favorites

tc

I think where you're getting confused is that high pinion is weaker in the rear, but stronger in the front by about 30%. The difference is which side of the ring gear you're engaging - the coast side versus the drive side. HP in the front engages the drive side.

4Crawler

iTrader: (3)

Yep, basically a reverse cut gear in the high pinion diff:
http://www.4crawler.com/4x4/4R_TechI...everseCutGears

In fact I have been running Marlin's rear high pinion diff that he set up for me about 7 years ago in the front of my '85 4Runner. After he broke it two different times in the rear axle, he gave up on the HP in the rear. He even tried setting up the gears a bit different the 2nd time around to try and make them a little stronger on the coast side, but still broke them.

masterwacker

Currie used to have, several years ago, a high pinion 9" dropout application. Supposedly custom gears and such. According to them the gears were "backwards" of other gears so they did engage on drive side. The even developed a locker for it too. Problem was it was flamin expensive and they didn't sell many. If I remember correctly the dropout only, with gears and locker, was like $3100. They said it was an awesome setup, but with how few they sold and the margin wasn't there so they discontinued it.

fillsrunner4

I believe the ford 9" is the only strong enough hp 3rd to put in the back of your truck. its real strong but like stated real expensive. if you have money to drop this would be a sick addition

44Runner

Dana 60 is plenty strong to run a high pinion in the rear. Some might say rockwells as well although they don't have an option...

fillsrunner4

i think with the dana 60's those tend to have more of an oiling issue. i dont dissagree that the dana 60 is a strong axle. Its huge. Another nice thing about the 9in is ground clearence. since the gears are reverse cut the oil is slung down instead of up which helps oiling the pinion and bearings. i could be wrong but this is one main reason why the high pinion rears are prone to more damage. lack of oil can quickly burn up gears and other parts inside the axle