Question for the Tranny experts/Hydramatic 101

[terry skinner]

Three cheers for Rick Staples. Well said.
Now what I got from this is that I will be a lot quicker to shift into
2nd. Also in light of this increase in pressure with changing to 2nd gear
makes me think that I would be better to shift than to change rear end
gears. I have already taken a run out to Puyallup and back just to try it. A
distance of 10 miles round trip. Out was in high gear, back was 2nd. If I
could get a shift kit to feel like 2nd while in drive that would be great.
Now I'm not talking about the gear ratios, just how it feels when it shifts
up or down.
I want to be able to feel the gear shift, not bang my head on the back
window when it grabs a gear.

Terry & Diane Skinner
Webfooted in Washington
'76 Glenbrook

 

[dave lowry]

Re: 3.42 Final Drive vs 3.55 Chain & Sprockets

Since this is one of the improvements on my shorter list, and there's a
significant difference in the cost of these two alternatives, I'd like to
compile some "real world" experiences so that I can make an informed choice.

If I understand correctly, Caspro's "Power Drive" changes the ratio between
the engine and transmission to effectively change the final drive's ratio
from 3.07 to 3.55. According to my minimal math skills, such a change
increases torque to the tranny by 15.6% (3.07 =F7 3.42 1.1564). Several =
of
you have posted the comment that this is an unaccepably risky means to
achieve the desired improvement in pulling power because it applies too
much strain on the TH425. Yet in other posts I have read that the TH425 is
a very strong transmission and very durable, especially if kept from
getting too hot.

Also, if I understand correctly, Cinnabar's 3.42 final drive has the
opposite effect. It reduces stress on the tranny because it affects the
ratio after the TH425.

My '76 weighs 11,740# when fully loaded for travel and we do not tow. It
has 94K miles on the original transmission, is serviced regularly and shows
no signs of trouble (no slipping, rough shifts, funny sounds or smells).

So here's the question; Should I believe Caspro's claims, or are there real
people out there who have experienced trannsmission failure after
installing the 3.55 set up. "Fess up" folks. If I have to spend the extra
$500 I will, but only if nessary.

Is this another theroretical "myth"?

I want to hear FACTS, please!

TIA

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)

 

[dave lowry]

Heinz

Thanks for responding. I like what you're saying, but now I've gotta ask a
couple more questions. You stated "I've had the Caspro kit in for about
33k, i.e. last tranny." I assume this to mean you installed the kit at the
same time you rebuilt the tranny.

I've been told the Caspro 3.55 Power Drive puts so much strain on our old
trannys that we can expect them to fail soon after installation. I have no
way of knowing for sure if mine has been rebuilt since I only have records
back to '92 (55K). But since it isn't showing any signs of trouble at 94K,
I suspect it may have been done sometime prior to '92.

Is there anyone out there who has actually had a tranny fail with a Caspro
Power Drive installed? And if so, what was the condition of the tranny when
the Caspro set-up was installed; how many miles were on the tranny, does
your tranny have stock gears, and has a shift kit been installed, and when?

Sorry to press for details, but in assessing the validity of this claim,
there's obviously a difference between adding the Caspro to an original
tranny with 100k miles and installing it in front of a freshly rebuilt unit.

The Caspro set up may be great when installed with a fresh tranny but too
risky if the the transmission is older. That would be understandable if
supported by actual experience.

Some more facts would sure be helpfull.

TIA

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)

 

[heinz wittenbecher]

> Heinz
>
> Thanks for responding. I like what you're saying, but now I've gotta ask a
> couple more questions. You stated "I've had the Caspro kit in for about
> 33k, i.e. last tranny." I assume this to mean you installed the kit at the
> same time you rebuilt the tranny.

Yes, that's correct.

>
> I've been told the Caspro 3.55 Power Drive puts so much strain on our old
> trannys that we can expect them to fail soon after installation. I have no
> way of knowing for sure if mine has been rebuilt since I only have records
> back to '92 (55K). But since it isn't showing any signs of trouble at 94K,
> I suspect it may have been done sometime prior to '92.

It may be still the first. My first rebuild (not first tranny) lasted about
125k and I'm hoping for longer on this one as I'm treating it to Synthetic,
better cooling and more frequent fluid checks. However, on the other side of
the equation, I know tow a little red Toad

>
> Is there anyone out there who has actually had a tranny fail with a Caspro
> Power Drive installed? And if so, what was the condition of the tranny
when
> the Caspro set-up was installed; how many miles were on the tranny, does
> your tranny have stock gears, and has a shift kit been installed, and
when?

A shift kit came with the kit. I was installing one anyways as I've had one
in for many, many miles. (100k+)

>
> Sorry to press for details, but in assessing the validity of this claim,
> there's obviously a difference between adding the Caspro to an original
> tranny with 100k miles and installing it in front of a freshly rebuilt
unit.
>
> The Caspro set up may be great when installed with a fresh tranny but too
> risky if the the transmission is older. That would be understandable if
> supported by actual experience.
>
> Some more facts would sure be helpfull.
>

Alright folks... fess/speak up. Inquiring minds want to know ( and me too


Heinz