TF_727 whining in reverse

[Cuda72]

I put a B&M shift kit in my 72 Cuda (727 trans) and ever since then the transmission whines when I place it into reverse. All forward gears are fine, but there is also a loud thump (or clunk) when shifting into 3rd under minimal throttle. When I'm in heavy throttle there is no problem. Before I drop the trans and perform a full rebuild on it, does anyone have any ideas on what could be causing this? The car has 40K miles on it, but when I bought it the kickdown linkage was missing so I hope its not a case of fried clutches or bands...

Thanks,
Mark
(Cuda72)

[tactransman]

(Sorry missed your post til now)
 A whiney noise only in reverse could be air in the hydraulic system causing the reverse boost valve in the valve body to oscilate
(go back and forth real quick).
It could be sucking air in the valve body somewhere that you did not get tight or misalignment when you did the shift kit. The thump into third sounds like gear train slack getting taken up quickly by the now firmer third gear shift.
Make sure it is full of fluid also(check it idling in neutral)

[Cuda72]

Thanks for the ideas. I'll pull the pan next week and see if the filter extension might be sucking air. I forgot to mention that I have a deep pan on it with one of the earlier stamped filter extensions, and I recently read that they would many times not seal properly to the valvebody, causing cavitation. As for the clunking, I only notice it when taking off slowly (drivetrain not under tension) so I guess its something I'll just live with. A few nights ago I was under the car and noticed that I have a huge amount of side-to-side play at the trans tailshaft yoke, so I'm also thinking that this may be what is causing some vibrations I also feel at cruising speeds. It looks like its time to pull the trans and rebuild it, as there is a slow leak from the input shaft seal and fluid drains from the converter overnight. While I have it apart, I'll replace the tailshaft bushing as well. This will be my winter project this year...

Thanks,
Mark

[moper]

If it's the B&M cheaper kit, the one in the flat package, not the "Trans Box" deal... You may have shift overlap. That means that 3rd gear clutch is applying before the 2nd gear band can release. That can be for a variety of reasons. Some places like it to be that way, it's not my favorite situation. The best thing really, is to addres it when you rebuild the trans. But expect to need to address it. I  certainly wouldnt live with it forever. As a quick fix, you can try adjusting the 2nd gear band a little lose. Say, 2.5 turns as opposed to 2 turns out from snug.