Hi Paul, I have been looking through Ford auto trans spec's in regards
to the Ford/Jatco parts JPG on your site, but cannot find those specs.
It shows 3.17 ratio. What Ford model is that from?
Thanks Steve Carlisle
Ford has changed the tranny number over the years.
Call
http://www.makcotransmissionparts.com/
<http://www.makcotransmissionparts.com/> sales and ask for the 6 pinion
rear
planet set from an A4OD. He will know what you are after.
Paul Lamar
Okay, I am even more confused. If I new for sure what tranny has that
ratio, I can buy a used trans locally. You tell me the pinion set comes
from a A4OD. You can buy many 4,5,or 6 pinion sets for many models as
upgrades. What confuses me now is you send a parts diagram for a E4OD. I
have a trans re-builder locally and say the 2 a quite different. I have
looked at the specs for the A4OD, and the offer standard ratio and Wide
ratio, but no planetary with the 3.17. Sorry for the confusion, it seems
not as simple as I had hoped.
Anyways, thanks for effort, Steve Carlisle
You are talking to the wrong person Steve.
Transmission re-builders know very little about planetary theory.
All they know about is how to take them apart and put them back
together. The E40D is a descendant of the C5 that came out in the
early 50's. Most if not all the parts are interchangeable. The early
planetary had 3 pinions, then 4 pinions and the latest incarnation
6 pinions. The hot rodders had six pinions long before Ford did it.
In the mean time Ford changed the transmission designation
number several times. One of them was the E4D. The E4OD has a third
planetary
for over drive. That is the "O" is in the designation. We don't use that
planet set. That smaller planet set is located at the front of the
transmission.
If you talk to the parts guy he will know what
you are after. The Jatco is a scaled down C6 and the parts look the same
but are smaller for the Japanese market.
The gear ratio depends on what part gets the input torque, what part
puts out
the torque and what part is held stationary. Early Tracy's were 2.17:1.
Later versions
were 2.85:1. For a rotary 3.17:1 gives the most power. It is also a
beefier planet
set. Ross made all three. It is the last planet set in the box.
Paul Lamar
Paul, Again, thanks for the help,
Steve Carlisle
Do you plan on building gear box?
Are you in the US? Milo is just south of Seattle.
I think. He travels back and forth to Texas sometimes :)
Brian Trubee is at Paine Field.
http://www.painefield.com/
Paul Lamar
Yes, I am looking at using good ideas from previous gear designs, and
dumping some other ideas. Coal Harbour, northern Vancouver Island.
Steve Carlisle
If you are considering plain journal bearings I would reconsider. I
would use needle bearings
like the Ross. It puts an additional load on the Mazda oil pump. Dave
Leonard seized one of Tracy's boxes with a plain bearing at Reno.
Fortunately it happened on the ground.
Another member of this list (Larry) who happened to be at Reno had one
of Tracy's boxes back in Marin County Ca. A another friend of Daves's
flew his airplane back 400 miles to pick it up. We had Dave back in the
air within hours at Reno.
The reason this problem did not show up sooner was it was just
marginally close to failure.
In fact there was a plumbing decision made that made the situation worse.
Dave used one oil line out of the engine that was supposed to fed the
turbo charger.
Dave simple teed off this line to feed the gear box as well. I
re-plumbed it
at Reno with a separate line to feed the gear box. That seemed to work
for Reno practice
and flying home but Dave never raced it at Reno because of the Mustang
fatal crash.
Day to day one never runs the engine flat out for 20 minutes at a time
at the same altitude.
Air racing is the acid test. If there are any weaknesses in the design it
will show up while air racing.
Paul Lamar
Wow Steve you really are out there in the bush.
I am surprised you have Internet access.
We stopped in Port Hardy in the C182 on the way up to Alaska.
Must be limited resources up there for gear box parts.
Paul Lamar
Well Paul;
We did give up on igloos prior to you living in northern Canada.
Back to serious; I think part of the confusion also stems from ford
using two different first gear ratios in different model transmissions.
Earlier transmissions used a 2.48 first gear with lower rear end ratios
like 3.55 or 3.27. Then fuel economy took over and they went to 2.56 or
even 2.19 gears. They then went to a lower first gear ratio of 2.85 to
get the same initial acceleration with much lower cruising RPM. As Paul
stated, the output ratio depends on the gear set and which parts are the
drive, driven or held.
I have a Grand Marquis with the 2.19 rear gears. Known as 8.5 but the
same housing and 8.8 carrier fits it.
Dale Davies
The 2.85 was the only one I have encountered. What year was the 2.48 ?
That all sounds like the front planet set. I am leaning toward the rear
planet set and 3.17:1 for aircraft.
Low RPM at cruise is the hot tip for car MPG. You get the road load closer
to the BSFC island. That is why the new Corvettes get 25 MPG on
the free way.
Mazda was really dumb to cruise the RX8 at 4000 RPM and 80 MPH after they
spent all the R&D money on the complicated intake manifold system
getting the torque up at 3000 RPM.
The answer is a computer controlled manual transmission that
automatically down shifts for passing.
Speaking of dumb I cannot figure out why Mazda did not put the
rotary in the Miata.
IMHO it would sell like hot cakes.
Paul Lamar
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