5 spd OD

["Gann, Jeff" <Jeff_Gann@domain.elided>]

I've had T-34's in two different IH's and never really noticed them being
really WIDE between gears.  My 66 T'all was 2wd with relatively high
gears (3.07 I believe) and I never had any trouble towing any trailer. (To
be completely honest, I only towed two different trailers that were
relatively
light before I began to part it out)  It may have been really taxed to pull,
let's say, a fifth wheel, but I would blame the 304 engine size.  But I 
wouldn't hesitate to pull a substantial amount of weight with my 67 T'ette 
with the T-34.  But the T'ette does have 4.88 gears and a powerlock.  
The tires are the stock size - 9.00-16's and are almost 35" tall.  If you 
don't mind the 1/4 mile throw between gears (no speed shifting here), then 
I think that they would be a better tranny for long distance towing due to 
the OD.  You might gain some additional control of the operating RPM with 
a T-36, but I believe that the OD of the T-34 would result in better gas
mileage 
for long trips, regardless of the size of the load.  I'm pretty sure that
1st
gear in the T-36 is lower than either the T-34 or T-35 (I've probably got
this
mixed up), but the granny low in my T-34 is plenty low enough for me.  

I'm still waiting to see how Scout people manage to get one to fit with
the divorced transfer case.  Epp, hurry up and install yours so we all
can see how you did it.

Jeff
(Don't take me wrong, I like the other two tranny's too, I just like the
T-34 better)

Jason Colavecchia" <jasoncolavecchia@domain.elided> wrote:

>I know alot of you guys are playing around with the idea to "upgrade" to
>the overdrive 5 speed,(T34) but there are a few things you should know
>about those transmissions before you get too excited.  One is that if you
>look at the ratio spread between gears, the OD is pretty WIDE between gears
>(especially between 3rd and 4th, which goes from 1.81:1 to 1:1) which
>basically gives you the 4 speed wide box type of performance.  The jump
>from 4th to 5th is .823 (I believe) and is probably fine if you are going
>from a stock 4 speed (or 3 speed) wide ratio transmission to the OD.  
>However, if you are into towing alot, I would strongly recommend the T-36
>direct drive transmission.  this would keep your overall rpm in 5th the
>same, but your shift points are much closer together than either the T-34
>or T35!  This is an ASSET when towing, as it allows you more control over
>the operating rpm of the engine for a given load or grade.  The T-34 would
>not be no better than a 4 speed wide box, in comparison.  On top of this,
>the overdrive only lowers your final drive rpm, not necessarily your fuel
>mileage.  This is because in order to get the overdrive condition, the T-34
>uses "4th" position in the gearbox to attain its .83 overdrive, and as a
>result the torque flow through the transmission must pass through the
>countershaft as well as the mainshaft, creating extra drag on the engine. 
>This is the SAME problem that occurs on big rigs with their overdrives
>creating the same conditions.  Although this problem is not as prevalent on
>the more modern transmissions (with such features as "low inertia" type
>engineering, this problem is slowly disappearing) it DOES affect the
>T-34....With a T36 (which is WAY more common) you get the same type of
>overdrive effect with the very close ratios, and at the same time get a
>true direct drive in 5th.  At that point, if you want an "overdrive" you
>can look at swapping out front and rear ring and pinions for numerically
>lower ratios, thereby giving your desired cruise rpm, while maintaining as
>efficient a drivetrain as possible 
>(example: T-34 in OD with 3.73 gears gives a 3.06 overall ratio at
>cruise...T-36 with 3.07 gears in 5th give 3.07 ratio at cruise!!! Drop to
>4th, and you get 1.21X3.07 for 3.72 ratio!!)

>Think about it!!!