allison performance ???

[dthollis1961]

Mac,

Sounds like mine. 1, 2, 3, lock-up, 4.

David Hollis 78 FC33 Springfield,IL


--- In WanderlodgeForum@yahoogroups.com, "mad6mac2000"
wrote:
> Hello all I am looking for some help with a allison 643
transmision, I
> am very peticular and it is starting to bother me a bit. We are
getting
> some weird shifts on our bird right now, 1st to second is fine and
> firm, 3rd to 4th is some what troubling on the climb through the
rpm
> range, I get a rpm change 2 times before shifting into 4th gear.
It is
> almost acting like it has 5 gears, is this the torque converter
locking
> up in the 3rd gear range? then shifting to 4th? I guess I think it
> should just shift 1..2...3....4. I have checked the shift points
> compared to rpm to speed and they are right on.
>
> this trans is the allison MT643 not 640
>
> Mac and Carrie Good
> 1978 31' FC NA