powershift auto query

[martincl]

I have an auto from a 66 Avanti.

When I move the lever on the box to Park, it is `spring loaded' and moves back when I let go. Is this normal? The other powershifts I have from Studebakers don't do this.

Thanks, Leon.

[silverstude]

 

Look at this page

 

It seems spring loaded because it's out of adjustment. Inside the case, there's a flange that looks like a sine wave.  The detent ball/spring for each gear position rides on this  and unless you have the adjustment correct it will not seat correctly, likely forcing the lever in/out of the position you want.  There's another l o n g chance that the transmission was changed out at some time for a Ford built unit.  It's basically the same as the PowerShift, but they use a different arc  on the gear shift geometry.

 

[martincl]

Thanks for the suggestion. Funny; I didn't think about it being faulty! I'll open up the box and check out the the detent ball/spring setup.

I did think about the Ford option as I also have a Ford unit that came out of a Stude Avanti. However it has the vacuum modulator and Ford numbers cast into the housing.

[dynolou2]

First: are ALL engine and transmission mounts known to be in good condition , not saggy or mushy.   The rubber bushing at the end of the shift linkage is known to rot with heat and age.  If the above are OK Then: with car on hoist or on stands, disconnect lever at shifter, remove cotter pin, place shifter in park and transmission in park. Check that driveline is locked and the adjust so rod fits thru bushing, refit cotter pin.   Lou Cote

[martincl]

Lou,

The auto is out of the vehicle.

If I hold the lever in Park, the output shaft does lock. If I let go of the lever, it springs back one position.

I will remove the pan asap and have a look at the internals. I'll report back.

Thanks, Leon.

[dynolou2]

I will give this more thought, but as you can see from the diagram above there is a .250 ball and spring that engages the rooster comb that is supposed to lock in all the detents. I have seen the spring broken or bent.     If you go to remove USE caution as it can and has been proven to fly  and disappear into the darkest corner of my shop.  Lou Cote

[Jim78]

8 hours ago, dynolou2 said:

   If you go to remove USE caution as it can and has been proven to fly  and disappear into the darkest corner of my shop.  Lou Cote

BTDT, Lou!   

If moving the external arm allows 6 positions (PRND21), the comb and detent ball are probably OK.  Needing to, and being able to, push beyond the P position would suggest that there is damage to the park latch itself.  I would guess that somewhere in history someone put the transmission into P while still moving.   At least fixing that problem wouldn't involve having to remove that #^%$* little detent ball.

[martincl]

Guys,

Thanks for your comments. Just to clarify; the lever doesn't move beyond P, it just won't stay there! The output shaft locks up in the normal fashion while I hold the lever in P. I can't see anything that looks a problem when I have the pan off and move the lever through all six positions. However I am not an auto expert! My conclusion at this point is that there is a fault but it's not obvious.

I have checked the power shift auto from my 63 R2 Hawk and another BW unit with 1963 Ford casting numbers (came out of an Avanti). Both of these stay in Park when I move the lever there.

Cheers, Leon.

 

[Jim78]

OK, I'm starting to get a clearer picture of what you're describing.  How do the other detent positions feel?  If all are "soft", it would suggest a bent or broken spring.  If the rest of the positions "snap" in, it would suggest that there is an issue with the comb. When the lever is in R, and you push it into P, is there the same resistance that you would feel between other positions?