727....Does it have a weakness?

[hooD]

Is it normal for the trans not to engage when put into Reverse or Drive when it isn't driven for a week or more?   I have to run the shifter through the gears once or twice for the trans to move.  Everything else is good!  Is there anything that can make it even better?   

[ChallengerHK]

I know that these transmissions don't engage the fluid pump in park, so I usually let my car warm up in neutral.  When I haven't warmed up in neutral I get the same thing you're talking about. I think that fluid drains out of the torque converter and it doesn't fill up until the fluid pump is engaged.

[Carlwalski]

ChallengerHK is along the right lines. That is what I have heard as well.
Nothing bad, just the the way it's designed. I think it helps the trans (draining itself?).

[tactransman]

It's normal,a Transgo shift kit fixes it. It doesn't hurt a thing,do what ChallengerHK said.

[Super Blue 72]

I've had sort of that issue and so has a friend of mine with a '68 Charger with a 727.  It sort of feels like the tranny is slipping, like you can rev it in gear until it's warmed up.  Doesn't feel engaged.  I think it's normal.  Makes it sound like I have a 4 speed car... 

[ShelbyDogg]

I've had alot of old Mopars and I never remember not being able to drive them right after starting them.  I believe that driving them easy was the best way to warm them up. If I couldn't drive them cold, I adjusted my choke.  Is there a bushing thak can be replaced somewhere to fix this drainback? This never would have flown back in the 60s and 70s.

Rob

[ntstlgl1970]

The TransGo kit has a modification to address converter drainback and Sonnax makes a replacement manual control valve with a built in check valve that does basically the same thing.

[ShelbyDogg]

What I am saying is that all of my stock unmodified trannies never needed any fill-up time. Why do yours need it now?

[ChallengerHK]

  The big difference I can see between now and the mopars I've owned in the past is that back in the day they were driven every day.  My Challenger gets driven now about once a week.

[tactransman]

The big difference I can see between now and the mopars I've owned in the past is that back in the day they were driven every day.  My Challenger gets driven now about once a week.

Exactly,that is the biggest difference. I drove mine rain,snow or shine, it was my only set of wheels in the '80's. Some trannies will do it worse than others depending on certain things like pump bushing to converter hub clearance.

[ShelbyDogg]

So If I have the problem I can make it better by always putting in a tighter front pump to converter bushing?

[tactransman]

Yes,some guys install a GM 350 turbo pump bushing but you really have to watch clearance on them because they can be too tight. They are wider too. It's easier to just install a Transgo shift kit. They also make a compression fitting with a one way check ball in that you can install in the front cooler line. (keeps the converter from draining down due to no air being allowed in the converter)

[ShelbyDogg]

So what mod is done in this Transgo kit that can be done without buying the kit?  Is it a special part or just a mod.  I've always used B+M shift improver kits, or Cheetah manual valve bodies in the past and never bought a Transgo?

[tactransman]

It is a special manual valve.

[ShelbyDogg]

Thanks Terry,   I remember seeing those pics , now that you sent them again.

Rob