Agreed...heat in the transmission IS problematic, especially when you add a
more powerful motor...
  When my old racecar had an almost stock motor I didn't have transmission
worries, but when we added a stroker crankshaft, which added a lot of
torque, we began to break stuff in the transmission.  I then added a
cooling and monitoring system and that solved the problem, as long as I
paid attention and drove with the internal transmission temperature below
around 300f...
  Later I changed  some things and added significant HP and torque...The
gears could not then handle it...around 500 lb/ft and 575+ hp... I searched
for custom gears and alternative transmissions that would take the load,
but none were available at any cost (below fully factory race budget), so
we had to tune-out some of the torque in order to keep the transmission
alive, I still had to be real careful with the torque or the input gears,
etc.. turned into a "corn cob" ...
  I even took a page from the NASCAR boys, who often have the transmission
internals cryogenically treated...It seemed to help a little, maybe..
  I swear by the Swepco line of gear oil..after managing that racer's
transaxle... Porsche 928 v8, BTW..Bumped up to 6.5liters and pared-down to
around 2900lbs...Big torque and heavy...

On Dec 31, 2016 8:51 AM, "Dennis Haynes" <d23haynes57@hotmail.com> wrote:

> When folks think of big engines and transmission damage they often only
> think of the concept of a large breaking stuff when abused or otherwise
> misused. The vanagon transmission also suffers from thermal limitations.
> While are some failures that are due just to stress such as cracked slider
> hubs and even broken welds on the 4th gear hub actual gear wear and bearing
> failures are usually the result of lubrication failure. I also believe that
> the carriers housings failing where the main ball bearing is pressed in is
> due to overheating. If your engine increases speed over grades than the
> transmission is transferring that new found horsepower and developing more
> heat in the process. Also, if the torque loading can now exceed the
> lubricant capabilities of keeping the gear teeth separated gear wear and
> more heat happens quickly. Even small changes such as changing tire size
> can have negative effects on transmission life especially for those who do
> extended driving at high speeds. As a person who frequently now drives from
> NY to Florida 65 to 75+ mph is typical cruising speed. So far the
> transmission has been Fun Bus's weak link especially after the change to
> 27" tires around 140K.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Don Hanson
> Sent: Friday, December 30, 2016 10:12 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: 094 5 Speed kit
>
>  Good points.. If you install a big torque motor behind a factory Vanagon
> transmission, you are exceeding the design parameters of the transmission.
> You'll need to learn to drive differently, if you can, or plan on breaking
> things.
>  Our Vanagons are pretty heavy and their WBX motors have a wide torque
> band, sure..117 ft/lbs?..that is not big torque, so we're not speedy, but
> you floor it, and go as fast as it'll take you.   Nice and simple...
> When you add a TDI, a Subaru, supercharged inline, or another big torque
> motor..and you use all it's torque, you're asking for breakage in the drive
> line... especially if you are banging low rpm short-shifts or driving hard
> on variable surfaces.
>   Vehicles are designed as complete systems.  The transmission was made to
> withstand what a WBX motor puts out, torque-wise, probably not much more.
>   I'm running an inline VW with a bit more Horsepower but only a little
> more torque... I have to run higher RPM to achieve better performance, but
> I don't stress the transmission that much more with larger turning force
> (torque)..  The trade-off is the ABA motor was designed as part of a
> passenger car, fairly light, so I've learned to NOT ask this light car
> motor to grunt at low rpms against the almost 5000lbs I usually weight in
> my Vanagon... It's not a lugging low rpm motor, especially in a Vanagon,
> but you probably could drive it that way in a stock sedan, (the car it was
> designed for)
>   I'd be diligent about keeping high quality lube in the transmission,
> maybe even add a temperature gauge, and apply all that big torque
> gently...Or spend more money and install a strong Porsche turbo tranny 😂
>
>
> On Dec 30, 2016 4:19 PM, "C. Abney" <tsudonimh@gmail.com> wrote:
>
> > It appears that many who have swapped to higher powered motors, bigger
> > wheels, and or overloaded their vans with accessories have had to
> > rebuild their transmissions frequently.  That is becoming more clear
> > as time goes on.
> >
> > Be modest about what you do change, and don't change your driving
> > habits from what you'd normally do given that you are driving a
> > vanagon. That's the take-home lesson I got based on my readings.
> >
> > On 12/30/16, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> > > In addition to the .73 fifth gear what final drive (ring/pinion)
> > > ratio
> > are
> > > you running and what size ties? All of this factors in.
> > > While it appears that reducing engine rpm is an ultimate goal there
> > > are disadvantages. It takes continuous horsepower to overcome wind
> > resistance.
> > > Horsepower is a function of torque and RPM. Reduce the RPM and
> > > torque
> > has to
> > > increase proportionally. Increased torque then becomes increased
> > > stress
> > on
> > > everything. So you save some fuel but decreased transmission and
> > > engine
> > life
> > > become victims. Keep in mind that the base of these transmissions
> > > were developed for engines less than 60 HP and vans somewhat lighter
> > > and with less frontal area than ours. These transmissions do not
> > > like torque over time. Also, keeping the engines running under load,
> > > pushing with more
> > boost
> > > to get the job dome makes for an NOx emissions issue.
> > >
> > > Dennis
> > >
> > >
> > > -----Original Message-----
> > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> > > Behalf
> > Of
> > > Darrell Boehler
> > > Sent: Friday, December 30, 2016 9:16 AM
> > > To: vanagon@GERRY.VANAGON.COM
> > > Subject: Re: 094 5 Speed kit
> > >
> > > Hi Jason,
> > >            I use a 0.73 ratio 5th gear from Weddle on my 86 vanagon
> > > 094 transaxle and it works fine. I have a tdi ahu converted to a tdi
> > > afn. I
> > have
> > > 20k miles on it and am happy. If you are staying with the same size
> > > tires you might want to go to the 0.70 ratio.  I rarely need to down
> > > shift on
> > the
> > > highway.
> > > Midwesty
> > >
> >
> >
> > --
> > It seems my TO-DO list is a FITO (faster-in-than-out)
> >
>