Trans won't shift when cold

[bobcat574]

I have a 92 aerostar that has issues with shifting when the transmissions is cold.

In order to shift out of 1st, I need to run the engine up to 4000rpm and hit a speed of 58-60 KPh before it will shift. It has similar problems with the other gears, but not as severe.

After driving for about 10-15 minutes, after the transmission warms up, it shifts perfectly.

Does anyone have any idea of what migh be the cause of this, and if so, does it require a large repair bill or is it a simple fix?

Thanks in advance

[Davescort97]

Have you tried changing the ATF to Ford Mercon. I think changing the fluid along with a new filter will help. I assume you checked the ATF level while idling in park. Low fluid would delay the shift.

[bobcat574]

I haven't tried the mercon fluid, but all fluids and filters were changed when I got the van last week. I even double checked the ATF levels and they were fine.

[Davescort97]

Good to hear it. I thought maybe the fluid had congealed or something.

[C. Cleve]

Hi,I am going to assume that you have the original trans and that you have OVER 100,000 miles on the vehicle, Problem is, The neoprene lip seals in the various trans components are by now as hard as a rock, After the fluid warms and in turn warms all the lipseals, they start to do their job, which is to seal the ie, clutch drums and servos that let things operate correctly to change gears.....NO way around getting the trans resealed in and out,,,,See Ya, Clay..

[Erroll]

My 1994 Ford Aerostar (208K miles) was slow to shift
when cold. When the engine was cold, I had to rev the engine
-up to shift into first or reverse. It would then shift
with a bang. The solution was to flush out all the old
transmission fluid. This was done with a machine (fluid exchanger)
that connects into the transmission cooling lines and extracts
all old fluid and substitutes new fluid without mixing the two.
The old fluid was dark gray and thick with residue from normal
clutch wear. After replacing all the fluid (15 to 20 quarts),
the transmission pan was drained (4 quarts), removed and
sediment in the pan inspected. Metal particles indicate
damage and soft fine gray sediment indicates normal clutch
wear. My pan had insignificant metal and much soft dark gray
sediment from normal clutch wear. The pan was cleaned and the
filter screen was replaced. After replacing the pan, more
transmission fluid (3 quarts) and one quart of TransX
additive (May or may-not be hoodoo) was added. The
transmission has been shifting like new for one month
now. If I had not performed this maintenence and allowed my
transmission to continue to bang when shifting, I believe that
I would have distroyed the transmission. I also believe that
a transmission shop would have sold me a transmission rebuild
of $2500 minimum instead of the less than $200 service described
above.