Tranny question?

[Charger74]

Ok, was looking at a post in general about the 73 SE/71 RT clone, in his descriptionhe has this for the tranny,


Transmission:

A727 Transmission Built.

kevalar Bands and Clutches.

5.0 Lever.

Chrysler Performance Shift kit.

Removed second Gear spring.

Slant Six 3rd Gear springs.

3,500 Stall Converter


Never heard of the blue highlighted stuff being done.  Can anyone tell me the benefits/problem with this??

[John_Kunkel]

The "second gear spring" is probably the accumulator spring which many still believe cushions the 2nd gear shift (it doesn't) and those same folks believe that removing the spring will "firm up" the shift (it won't).

I have no idea what "slant six 3rd gear springs" means since the /6 727 uses the same front clutch springs as the V8 and the 904 uses a single coil spring.

[chargerbr549]

Since we are kind of guessing what they meant by their description, on the remove second gear spring they could be refering to the intermediate servo which applies the "second gear band", usually has two springs and in the shift kits they have you remove the outer spring and just leave the inner one and like John said all 727's used the same type of springs in the front clutch but they used different spring counts depending on application and engine size.

Kevin

[Charger74]

Cool thanks, just thought it was kind weird looking.

[Ghoste]

John, I have to disagree that blocking the accumulator will not firm up the shift.  I have done it and it firms it up a LOT.  Too much for a street car in fact.

[John_Kunkel]

John, I have to disagree that blocking the accumulator will not firm up the shift.  I have done it and it firms it up a LOT.  Too much for a street car in fact.

I have no retort for those who claim anecdotal experience with spring removal other than to ask:

Did you take an operating transmission, in a car, do nothing but remove the spring, reinstall the VB and pan and feel a significant difference? If you did, do some research on "the placebo effect".

If OTOH, you removed the spring incidental to overhaul, other mods, etc. how do you know the spring removal was solely responsible for the perceived improved shift?

The laws of physics and hydraulics easily prove that the accumulator spring does not cushion the 1-2 upshift simply because the accumulator piston moves AWAY from the spring on the 1-2 shift. Study the fluid flow diagrams in any Mopar FSM and you will find that the cushioning effect of the accumulator is strictly a hydraulic function, the spring plays no part.

The text in earlier versions of the FSM go into more detail on the accumulator's function than later versions.

[Ghoste]

Anecdotal??  Hardly.  My real world experience was that with no other mods but to remove the spring and install a blocker rod the shift became not just firm but harsh.  Hardly a placebo effect.  Removing it and reisntalling the spring had the opposite effect.

[John_Kunkel]

By the way, simply removing the spring as you originally stated is a lot different than removing it and installing a blocker. As I stated, the cushioning is done hydraulically; blocking the piston removes the cushioning effect.

[Ghoste]

Details?  Okay, as a matter of fact, yes, I did lie underneath the car and block the accumulator looking for a firmer shift.  The blocker was removed and the spring replaced NOT to prove a point but because the shift was too firm.  I haven't had a chance to do that placebo research yet but my limited understanding of the complicated term tells me that I must have experienced an amazing placebo in this case.
Out of curiousity, have you ever tried it?

[John_Kunkel]

I have tried solely removing the spring, no difference; that's what lead me to do the research on the function of the accumulator.

[Ghoste]

Did you try it with a rod in there?  (note I haven't called your experience anecdotal or a placebo effect)

[John_Kunkel]

Nowhere have I made the claim that blocking the piston wouldn't firm the shift (read entire thread), in fact that is the ONLY accumulator mod that will affect the upshift.

In your initial response you made no mention of the blocker rod which is infinitely different than merely removing the spring.

BTW, the term "anecdotal" merely means "the story of your experience" which bears no intended insolence and the term placebo effect would be totally appropriate if a perceived firmer shift feel would have come about due to solely removing the spring as your OP alluded to.

[Ghoste]

Although the original misunderstanding lies with me, ( I see where you had only mentioned removing the spring) if you re-read my first post the only modification I did mention was blocking it.