95 Ranger transmission problem

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Thermionic - 02 Feb 2007 01:07 GMT

My 95 Ranger has a problem that 1 mechanic and 1 transmission specialist has
not been able to figure it out. The Ranger is a '95, with 4L V6, and 4WD
with automatic transmission. Under certain driving conditions, the
transmission seems to go into neutral for no reason, the engine revs up like
it has no load and then it goes into gear again. I can make it happen every
time by driving up to about 30mph, coasting to about 20mph and then
accelerate. The rpm will jump up a bit, the truck decelerates a little then
engages into gear again and off we go. This can also happen sometimes if
traveling around that speed and going up a slight incline, and perhaps
accelerating a little.
The most exciting time it does it is at random times when traveling
between about 40mph and 55mph. It seems to happen only when cruising on the
highway at a steady speed, not during acceleration. Turning off the
overdrive does not stop it from happening, but it has never happened while
driving in gear position "2" at any time at any speed. I cannot make it
happen at will as at the lower speed. When the outside temp is below around
30 degrees F, the problem is practically nonexistant as far as the higher
speed phenomenon is concerned. I still does the lower speed thing at any
temp though. The transmission was rebuilt at around 90K, the problem existed
both before and after it was rebuilt. It did run better after rebuild, but
this problem never went away. The rebuilder did not have any idea what it
was that was happening. The fluid is not low, never was, and it is not burnt
as far as my nose can tell.

Thanks for any ideas..............T

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Ford Tech - 02 Feb 2007 02:55 GMT

> My 95 Ranger has a problem that 1 mechanic and 1 transmission specialist
> has not been able to figure it out. The Ranger is a '95, with 4L V6, and
[quoted text clipped - 21 lines]
>
> Thanks for any ideas..............T

Ok first question. Are you sure that the TCC is in fact engaging? What are
your RPM's at cruise down the highway at say 60mph? If they are above
2500rpm's I would say its not engaging at all.

Second question. Did they replace the torque converter when the tranny was
rebuilt? If not, it sounds to me like the one-way clutch on the recirculator
disc is slipping and that could be causing your problem. It sounds to me
like when you are needing some torque the clutch is slipping momentarily and
then finally kicking in.

Only other thing I can think of without studying a cluch apply chart or the
internals of the trans, would be that the direct clutch is slipping, as you
have taken the intermediate band out of the equation by putting it in "2",
but the forward clutch is still engaged and operating normally.

Other thing I was thinking about was maybe debris left in the trans cooler
could be washing back into trans and causing possible fluid flow blockage.

Anyone else with more trans experience have any other ideas of what might be
causing this?

Ford Tech

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Thermionic - 03 Feb 2007 02:34 GMT

Thanks for your response.........

> Ok first question. Are you sure that the TCC is in fact engaging? What are
> your RPM's at cruise down the highway at say 60mph? If they are above
> 2500rpm's I would say its not engaging at all.

RPM is around 1900 at cruising speed on level terrain.

> Second question. Did they replace the torque converter when the tranny was
> rebuilt? If not, it sounds to me like the one-way clutch on the
> recirculator disc is slipping and that could be causing your problem. It
> sounds to me like when you are needing some torque the clutch is slipping
> momentarily and then finally kicking in.

Yes supposedly they replaced it. In fact the converter started getting
rather noisy after a while and I had to take it back in for replacement
under warranty.

> Only other thing I can think of without studying a cluch apply chart or
> the internals of the trans, would be that the direct clutch is slipping,
[quoted text clipped - 3 lines]
> Other thing I was thinking about was maybe debris left in the trans cooler
> could be washing back into trans and causing possible fluid flow blockage.

Is the cooler flowing coolant all of the time? Or does it only kick in
with some kind of thermostat? The thing definately has much much less of a
problem in cold weather. Do you know of a website that has information and
hopefully diagrams and pictures that describe the workings of automatic
transmissions? I don't really know much about them and would like to
understand them better. I would like to take the Ranger to another
transmission tech and then be able to understand at least a little about
what he is talking about.

> Anyone else with more trans experience have any other ideas of what might
> be causing this?
>
> Ford Tech

Thanks again!!!..............T

Reply to this Message

Ford Tech - 03 Feb 2007 03:13 GMT

> Thanks for your response.........
>
[quoted text clipped - 38 lines]
>
> Thanks again!!!..............T

Ok you have the 4R55E transmission. I would suggest you find a transmission
manual for your truck. Helm makes a factory authorized manual for your
trans. It will have descriptions for operation, and repair. Some include
troubleshooting flow charts to help you diagnose your problem. I warn you,
you could be troubleshooting for DAYS if you follow the flow chart to a T...
That and you probably dont have all the tools required to do the diagnostics
correctly.

Ford Tech

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Ford Tech - 03 Feb 2007 03:48 GMT

> Is the cooler flowing coolant all of the time? Or does it only kick in
> with some kind of thermostat? The thing definately has much much less of a
[quoted text clipped - 4 lines]
> transmission tech and then be able to understand at least a little about
> what he is talking about.

Sorry forgot to answer this question.

Here is a small test you can do yourself at home to check pump flow and
cooler flow:

Transmission Fluid Flow

To check for proper fluid flow, use the following procedure:

NOTE: The linkage, fluid and control pressure must be within specifications
before performing this flow check.

1.. Remove the fluid level indicator (7A020) from the fluid filler tube.
Place a funnel in the fluid filler tube.

2.. Raise and support the vehicle. Refer to Section 00-02 if necessary.

3.. Remove the cooler return line from its fitting in the case (7005).

4.. Connect a hose to the fluid cooler tube (7A031) and fasten the free
end of the hose in the funnel installed in the fluid filler tube.

5.. Lower vehicle. Start the engine and set idle speed at 1000 rpm with
the transmission (7003) in Neutral (N).

6.. Observe the fluid flow at the funnel. When the flow is solid (air
bleeding has been completed), the flow should be liberal.

7.. If there is not a liberal flow at 1000 rpm in Neutral (N), low front
pump capacity, main circuit system leakage or cooler system restriction is
indicated.

Check fluid cooler inlet tube (7A030) and fluid cooler tube between the
transmission and radiator (8005) for restrictions. Check for restrictions in
the metal or rubber cooler lines to and from the transmission fluid cooler
(7A095) (if fluid equipped). Check and feel all bends for kinks especially
transmission fluid cooler rubber hoses, that would restrict flow and could
result in transmission overheating or lack of lubrication.

8.. To separate transmission concerns from cooling system concerns, repeat
by connecting a hose to the fluid cooler inlet tube

A liberal flow as described by this procedure would be a flow that will take
the shape of the hose for atleast an inch after the fluid leaves the hose.
With the trans in neutral there shouldn't be very much pressure in the
system about 5-10psi.

Then I would do as I recommended before. You can either buy a manual or
search the web for 4R55E transmission.

Ford tech

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Thermionic - 09 Feb 2007 02:11 GMT

Thanks again for your help. I will post anything I find out at a later time,
if its worth posting.............T

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