Straight off the Eaton website

http://www.eaton.com/EatonCom/Produc.../FAQ/index.htm

I use Castrol Hypoy C 80/90

 

after looking at their websire FAQ's what is the reason for this?

Can I use the stock bearings?
In most cases the Truetrac units work with the factory (stock) bearings. The exceptions are: 10 bolt 8.5\8.6 GM axles, the “Performance” Dana 35 & 44 and GM12 bolt with 35 spline axles. No other “special” setup is required.

 

In the case of the 8.5/8.6 rears, the reason is because the same carrier is designed to work in both rears and to make this happen requires hybrid bearings be used.

 

funny i looked at their FAQs and didnt find anything.. but now i c it was their.. and i also emailed them and i just heard back from them.. said no synthetic and no additives just standard 80w90 mineral based oil is recommended.. so thanks for everyones replies... i got my question answered...

 

No problem

 

Yeah the whole 28-30 spline change... Got Cha

 

80/90 penzoil

 

heres some pics of a tru trac just after a few months running, nothing major just glad i checked before reinstalling it















i posted these pics for the simple fact if anyone runs one then does a gear swap they need to check these parts, these parts arent your normal wear parts, these are the heart of the tru trac, luckly i checked it out before reinstalling it.. didnt have any issues to begin with just wanted different gears, i ran this tru trac just a few months i wont elaborate what i think was failure even though i have a good notion as to what happened. it is under warranty, thanks to Rons machine, BUT what i am getting at is the first question i was asked was: what oil am i running was it synthetic..

 

What oil were you running?

 

??^^Yeah that^^??