Transmission Fluid Change

[hemogoblin]

Hi All
A number of years ago in my shop I used to do changovers to B&M Trick Shift
fluid or Ford fluid in GM cars. Both were "stiffer shifting fluids" ( higher
viscosity I believe with B&M highest). To accomplish this I would disconnect
the trans line at the Radiator , place a rubber tube over the end and direct
it to a clean drain pan. By cranking the engine, the old fluid would be
pumped into the drain pan. It was a start and stop process adding new fluid
when appx. amount filled the pan. This was easiest with B&M since it was
Blue in color you could see the change, but worked with others if you
measured. Before the drain was started I would drain Fluid and change
Filter. This method worked and would enable total replacement of
transmission fluid, for a change to Synthetic.
PS fluid change from stock to B&M used to give my Customers a little more
life for their tired Transmissions.
Mark '77Palm Beach LINY
Hemogoblin's.com

 

[patrick flowers]

>
> OTOH, I still would NEVER put Dexron in a Ford, Volvo, Toyota or other
> tranny that specified Type F. (Not all Fords, Toyota, Volvos, et al, do so.
> RTFM.)

My only experience with this sort of substitution was a hot-roddin'
buddy of mine in high school that put Dexron fluid in his Mustang's
transmission - neither of us knew any better. Within 250 miles, the
transmission was toast.

Of course, back then I thought that auto trannies were for old
folks! My '66 Mustang had a four-speed.

Patrick
- --
Patrick Flowers
Mailtoatri63

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[zachary zehnacker]

Rick,

Since we have always run Type F in our racing GM Powerglide transmissions,
we switched over the GMC about 2-3 years ago (~30-40,000 miles) to get
everything the same. It is hard to say how much difference it made because
we put in a rebuilt trans at the same time. It seemed to shift much
firmer, but that could be the trans too. It might also lower the converter
stall speed (or it could be the replacement converter we put in at the same
time) which might pick up gas mileage, but probably hurts performance.

We are probably going to switch to the synthetic Mobil 1 (now available at
the new local Autozone) soon which is Dexron. We might wait another year
and rebuild the trans at the same time. Note that we are towing the race
car trailer with our GMC, so we rebuild more often to be safe and may have
different results than non-towing GMCers.

One thing to consider is Type F availability (or lack of). This could be a
regional thing, but, by us, you can walk into most stores that sell engine
oil and get Dexron trans fluid. Type F is much harder to find. The local
Pepboys and Autozone only have one brand each (Pro-Line and Coastal) in
Type F. A lot of places don't have it at all anymore. The local Shoprite
used to actually be the place we would get it all the time as we liked to
run the Quaker State Type F and they always seemed to get it. We buy a lot
of trans fluid for the two race cars and the GMC. I can't even imagine
what the suppliers thought when they saw a Shoprite selling out of Type F
trans fluid all the time . Availability isn't really a big problem for
us because we always keep about 15 quarts in stock in the race car trailer.
For others, it might be more of a problem. At least with the Mobil 1,
regular Dexron can be substituted if the Mobil 1 can't be located.

Zak

>BUT, based upon what knowledge I do have, I would expect that one COULD put
>Type F in a THM425, and achieve slightly firmer shifts/less slippage. I
admit
>being reluctant to try this without some reports from the field. I would be
>interested if anyone out there has tried this and what their experience
>was.???
>
> OTOH, I still would NEVER put Dexron in a Ford, Volvo, Toyota or other
>tranny that specified Type F. (Not all Fords, Toyota, Volvos, et al, do so.
>RTFM.)
>
> My .02, opening the floor for discussion.
>
>Rick Staples
>'75 Eleganza
>Louisville, CO
>
>

>