PT36 retarder & other things

[Rob Robinson]

Hi Shane. I've always thought it was best to keep the tranny temp at or
below 200F. I guess I have been a little too conservative? I alternate
between the brakes and the retarder in the mountains and so far have been
able to get down slowly without ever getting my tranny temp much over 200.
Of course it helps to read the Mountain Guide and choose the lesser hills.
My recent trip back from Oshkosh BB Rally saw lots of long hills and both
the brakes and the retarder got good workouts.

On 22/08/07, sfedeli3 <sfedeli3@...> wrote:
>
> Hi Art,
>
> The tranny will heat up pretty quick- be sure to keep it below
> 320-330 degrees or you'll shorten the life of the tranny fluid
> greatly. Most commercial bus drivers have to change the tranny fluid
> every 50K miles when using the tranny retarder often. Mine easily goes
> from 230 to 300 degrees when descending a steep off-ramp. One way to
> slow the heat is to engage the fan override and let the hydro fan rob
> 25-30 horses from the engine and cool the tranny fluid a little
> quicker. On an off-ramp it does not make much difference, but on the 3
> or 4 mile grade, you can usually make it to the bottom under 320
> degrees if you also use the service brakes along with the tranny brake
> and fan to slow the coach down.
> The thin sheen of oil is probably the result of a leaking hydraulic
> fan hose or tranny hose somewhere. Check all of the big 1-1/2" hoses
> going to the tranny and hydraulic fan motor. If you've never replaced
> them, it may be about that time. I drove 200 miles a few years ago and
> arrived to find my toad covered in oil from the hydraulic fan sump. As
> is turned out, the supply line from the sump to the fan motor had
> rubbed against a hose fitting and ruptured. Thank goodness for dawn
> dish detergent. What a mess! The tranny cooling lines are under VERY
> high pressure when you engage the tranny retarder. I'd have them
> checked out ASAP or just replaced if you don't know how old they are.
>
> Shane Fedeli
> 85PT40
> Hershey, PA
>
> --- In WanderlodgeForum@yahoogroups.com,
> "amweath"
> wrote:
> >
> > Got back Monday eve. from the Montery Historic Auto Races. The Bluebird
> > performed almost flawlessly. I do have two concerns.
> >
> > When coming down the grade into San Luis Obispo, I had the first occa-
> > sion to use the retarder. The grade is steep but short (2nd gear going
> > up). What was alarming was how fast the trans temp went up - maybe 25
> > degrees in 15 seconds of use. Is this normal? It does hold well though.
> >
> > The other item was a light sheen of oil on the back of the coach when I
> > got home. I traveled about 800 miles. I can't imagine it coming from
> > the exaust - not a hint of smoking.
> >
> > The races were quite an expirience. They featured the Indy Roadsters
> > from the mid-50s to the mid-60s among, of course, many other types.
> >
> > Any insight into the two concerns is appreciated.
> >
> > Art Weatherly
> > Riverside Ca
> > '85 PT36
> >
>
>
>



--
Rob, Sue & Merlin Robinson
94 WLWB


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