904 over-revs going into 2nd

[mopardad1]

Our 69 Barracuda street/bracket car is over revving (shift point 5500, but revs to 6200) when shifting into 2nd gear. We just replaced the old Hurst Pro-Matic shifter with a B & M Quick Silver (a great inprovement) thinking that was the problem. But during last Friday night's bracket race it still over revs going into 2nd. The transmission (904) has one season on it, is set-up with a low first gear and a shift kit. The converter is a Boss Hogg 3000, again one year old. The engine is 10:1 360 MP 509 hydraulic cam (300-350 hp), 8 3/4 Sure Grip with 3.91 and BFG drag radials. Under throttle it will go into gear, but on the return road under no throttle it just revs.
The trans oil is still clear/red and has no smell.
We're perplexed...
By the way we STILL WON Friday night, 4 rounds (chevy, bye, chevy, chevy)

 

[mopardad1]

Ate the kickdown band and scored the drum. Rebuild time.

 

[69signetv8]

What the heck...might as well readjust the kickdown tight and back off 2 turns to see if you have anything a little tighter or left :evil4:

 

[340mopar]

How do you have the kick down linkage hooked up? It almost sounds like you are not getting full pressure.


Chuck

 

[C130 Chief]

So when you added the low gear set did you also grab the governor out of the donor transmission? If not, there's your problem. (With the lower gear the tailshaft still thinks the engine is turning 5500 but due to the increased reduction, you are actually running over 6000)

Later transmissions with the low gears used a 1.06" diameter governor weight, so you will need to swap the whole governor housing if you have the earlier 1.00" governor.