Re: WHICH TRANSMISSION FLUID FOR ULTRAMATIC

Posted by Tim Cole On 2013/2/20 9:40:48

Dear asa:

Type F has no friction modifiers and is fine for the 23rd series car.

For the 56, Packard recommended the friction modifier - read Dexron - in a TSB. Given that D range utilizes a synchronous shift the modifier will help reduce direct clutch wear. However, if you only use High range it doesn't matter.