Auto trans tip- Shift points
Thread Starter
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
Auto trans tip- Shift points
Questions on changing the shift points on a c4 come up often. Moving the adjusment on the tv cable will alter the shift points because line pressure to the governor is altered. THIS IS NOT AT ALL CORRECT! DO NOT DO THIS.
On a 4l60e(94-96) Shift points are changed through pcm reprogramming. Earlier units use a governor. Like an early distributor, they contain weights and springs. The only correct way to change the shift points on these transmissions are to alter or change the weights and/or springs. This is often done through trial and error. Some guys have "formulas" regarding rpm vs weights(in grams) to achieve the correct shift rpm for their combination
On a 4l60e(94-96) Shift points are changed through pcm reprogramming. Earlier units use a governor. Like an early distributor, they contain weights and springs. The only correct way to change the shift points on these transmissions are to alter or change the weights and/or springs. This is often done through trial and error. Some guys have "formulas" regarding rpm vs weights(in grams) to achieve the correct shift rpm for their combination
Le Mans Master
Joined: Apr 2005
Posts: 8,077
Likes: 4
From: Scarborough ONTARIO
One Q here bud,
If u change weights alone what will effect?
if u change springs what will effect?
U modified my governor just the weights though, now 3-4 takes place at 42 mph instead of 38 before, which is good i like it, now i wanna shift at 45 mph (3-4), will u have to grind some more on weights or replace springs with lighter springs?.
Keep the good info flowing.
If u change weights alone what will effect?
if u change springs what will effect?
U modified my governor just the weights though, now 3-4 takes place at 42 mph instead of 38 before, which is good i like it, now i wanna shift at 45 mph (3-4), will u have to grind some more on weights or replace springs with lighter springs?.
Keep the good info flowing.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Though I haven't installed it yet, I have the B&M Recalibration Kit and the instructions say that, generally, the weights will move all the WOT shifts uniformly whereas the weights will spead or compress the differences in the shift points.
Indeed, on the non-E A4s, adjusting the TV cable will change part throttle shifts but it also changes line pressure which can be detremental to tranny life.
Indeed, on the non-E A4s, adjusting the TV cable will change part throttle shifts but it also changes line pressure which can be detremental to tranny life.
