Re: Packard rear end gear ratio and LSD/TT

Posted by HH56 On 2019/3/12 11:25:48

There were several ratio choices for the regular Dana axles in 56 and according to bulletin 56T-8 5 ratios were available with the TT axle. 4 on one assy and the highest -- 4.09 -- required a completely different assy. TT was a later addition and there is no specific mention in the earlier printed versions of parts and service literature. Other than the bulletin and some theory of how it operates in the April 56 service counselor there is no real nitty gritty of how to repair one other than a statement that a TT rear end was serviced in the same way as regular axles. If there was a problem with the TT part the unit was to be replaced as an assy because there were no detail replacement parts available.

From what I have read in other publications the unit Packard used was a very early version of the LSD. I believe Dana changed the clutch engagement from a single tapered contact surface around the circumferance of the clutch to multiple clutch discs with a much greater contact surface in the next LSD axles to make the clutch locking more positive and able to hold more torque. If that is the case I am not sure I would want the early Packard version even if it were easily found and could be mounted without difficulty.