When I go to buy bearings for the rear axles of my Bronco, I am offered 2 different size bearings at the auto parts store. Mine takes the larger of the 2. What other ways are there to figure out which 9 inch I have?<br> One more thing. What weight oil do you use in your Dana 20 transfercase? The book says strait 20 weight!

When you look at your rear 9", if it is a "true" big bearing deal it will have a flared out center section, not a round banjo like center section. On your tcase I looked at my '77 shop manual and they say SAE 50 wt above 10 degreesF and SAE30 below 10degreesF. Could not find a specified weight on the axles-this is listed "Hypoid Gear Lubricant" part # C6AZ-19580-B. We just usually run a name gear oil-80wt-Valvoline, Havoline Kendall etc... I do have friends that swear by synthetic on tcase and axles once they are broken in. Valvoline synt. is one.<br>HTH,<br>Karl<br>66x2, '74&'77