True hi9 or hi pinion 60?

superglock · Sep 23, 2010

I am thinking about a new rear diff set-up. what are you running and how has it worked out?

Is anyne running the hi9? How is it working and how is the noise at road speed?

I am running a YJ at stock length so the high pinion is nice.

Damnyankee · Sep 23, 2010

no noise on the road for the high 9. i drove it all over when i lived in canada. I have the older version (5.38:1, not the new mega9 with the 5.4:1)
I would not put a hp60 in the rear of any vehicle.
my hi9 has been a godsend.

IF you go with the hi9, i have one suggestion.. make sure to get this for it.
http://bluetorchfab.com/store/product_info.php?cPath=19_64&products_id=305

don't get the hi9 without it.. this thing takea a beating.... and is well worth the investment of 150 bucks to protect th 2000 +

here is a pic all put together
Armor onthe hi9

drive shaft possitio difference Vs. Low pinion 9"

beef comparasin

Hip · Sep 23, 2010

the only issue i have heard about is "if" they use a true 9" ring gear or the 8.8 ring gear.

one of the companies uses the 8.8 and there is a big difference. the 8.8 has only one tooth in contact with the pinon and the true 9" always has two teeth in contact so is twice as strong in that area.

that is the dividing point for strength of a ring and pinon, ford 9" is the smallest that always has two teeth.:awesomework:

Damnyankee · Sep 23, 2010

Hip said:
the only issue i have heard about is "if" they use a true 9" ring gear or the 8.8 ring gear.

one of the companies uses the 8.8 and there is a big difference. the 8.8 has only one tooth in contact with the pinon and the true 9" always has two teeth in contact so is twice as strong in that area.

that is the dividing point for strength of a ring and pinon, ford 9" is the smallest that always has two teeth.:awesomework:

the currie hp9" uses an 8.8 ring rear out of the eploders or expeditions.
the true hi9 uses a custom gear made by richmond. that is actually 9".

you can see in my photo that the stock 9" gear, same ratio is smaller than the hi9 gear

Hip · Sep 23, 2010

Damnyankee said:
the currie hp9" uses an 8.8 ring rear out of the eploders or expeditions.
the true hi9 uses a custom gear made by richmond. that is actually 9".

you can see in my photo that the stock 9" gear, same ratio is smaller than the hi9 gear

yeah i couldnt remember who but i tremembered the issue.... thanks for clearing that up.

wishicouldwheel · Sep 23, 2010

hi 9

I've built a few spider 9's for a tj's lj's and a zj and also dealt with dynatrac and for a rig like your's i'd go hi 9 all the way. Driving on the coast side of the gear is what makes a high pinion in the rear weak but on the hi9 the thrust block keeps the ring gear in place thus making it not as big of a deal. besides the ring gear difference the hi9 also has the 3rd pocket bearing which the chp doesn't have which is where most of the strength of a 9" is.... man i should be a rep :kiss: