2002 3.0 Automatic Transmission Question

[Motorsport126]

Hello all! I have a question about my 2002 Ranger. Its an automatic with 4wd and a 3.0 liter.
When the truck is first run while cold the transmission engages into reverse properly. However
after it warms up there is approximately a 3 to 4 second delay when going from drive to
reverse. I was told by the transmission shop that the delay is most likely caused by the reverse
band, that they tend to 'come apart.' The transmission seems to be holding strong in reverse
with no slipping. Is it possible that there is a 'leak' somewhere in the valve body that when the
transmission fluid gets warm that it seeps through a seal? I was curious if anybody has had this
issue and what the repair was. I know that reverse tends to go out on these and i don't know
if this was the symptom of it beginning to go out. The truck has 151,000 miles on it and i
don't have any vehicle history so i can't tell you if anyone has been in it.
Thanks for looking!

 

[superj]

welcome!! i don't know the answer but just wanted to say howdy

 

[Motorsport126]

howdy!

 

[RonD]

Welcome to TRS

You have a 5R44E transmission in a 2002 3.0l Ranger

The delay after warm up can also be a pressure issue, change fluid and filter, check fluid for burnt smell, i.e. slipping bands(brakes) and/or clutches
Check pan and filter for metal bits


All automatics run on fluid pressure, ATF fluid
They have a pump that spins at engine RPMs
This creates the 80 to 200psi pressure needed
The pressurized fluid is sent to the Valve Body, the valve body routes the fluid to the Clutches and Bands, to engage and disengage as needed to select each "gear"/ratio
Older Automatics used ball/spring valves and vacuum in the valve body to select gears
Newer(1995 and up) use electric solenoids for gear selection

Forward gears need 90 to 110psi to hold engagement
Reverse needs 140 to 160psi to hold engagement

The higher pressure for Reverse is often why automatics show first signs of trouble with slow or no Reverse
There are pressure ports on the side of transmissions to test internal pressure in various gears, so pressure can be tested in Reverse, and if its OK then issue would be Mechanical, i.e. clutches and/or bands(brakes)

 

[Motorsport126]

Thanks for the reply. I went out and bought Mercon V and a new filter. I have an oil pressure test gauge but i think its limited to 100 psi, i'd have to check. Would you recommend changing the EPC while you have access, like you should change an oil pump if you have the pan off? I also plan on installing a transmission cooler while i'm at it so that can't hurt.

 

[RonD]

400psi gauge is recommended

Good reference article here, on whats on and off in each "gear" and expected pressures: https://atracom.blob.core.windows.net/gears/2003/2003-05/2003_5_50.pdf

 

[Motorsport126]

Thank you!

 

[Motorsport126]

I went ahead and changed out the fluid and filter. I didn't find any metal in the pan, the fluid didn't smell burned but was really dark. I'm pretty sure the pan has never been off the truck but i may be wrong. I don't know if the factory pan gasket had the metal tabs to make sure it isn't compressed too much or not but that's the gasket that came off it. The 'magnet' had between around a tablespoon (actual measuring for baking) of grey material on it but no metal. After taking for a test drive all gears feel better. The shifts aren't has hard and there was a really weird intermittent 'buck' like it was upshifting two gears and hitting rough but that seems to be gone. After driving it around 30 miles in highway and stop and go traffic throughout town it is exhibiting an almost exactly 3 second delay going from drive to reverse. I haven't had a chance to check the pressure yet.

Would adding a dedicated transmission cooler be beneficial? I've gotten mixed results when searching. Does the transmission fluid need to reach an operating temperature based off of the radiator temperature or is the radiator cooling the fluid? Also if a transmission cooler is installed will the fluid be too cold for proper operation? I live in Pennsylvania and we can get some cold days mid winter.

 

[RonD]

Trans fluid operating temp is similar to engine cooling operating temp, few degrees cooler 170-200degF
Second trans cooler is always a good idea even in cars

No it won't ever run too cold only too hot
Torque converters generate the most heat

 

[Motorsport126]

Thank you for your help!

 

[55trucker]

One would not need a very large stand alone trans cooler, something like the Tru-cool L7B low pressure drop would do fine.
It's GVW is far more than you'll ever need, it's compact, easy to install.

 

[Motorsport126]

I'll look into it, thanks!

 

[55trucker]

I take it that your truck does not have the optional mounted trans cooler?

Hard to miss, in front of the A/C condenser, mounted on the passenger side of the rad header.

 

[Motorsport126]

I did go out and take a look and I see it does. The line from the transmission goes to the upper radiator. The return line then comes out the bottom of the radiator and goes to the right side of the radiator but it looks like it was cut. A rubber line runs up to the cooler then returns to the return line. I looked and seen lines going into the radiator and made the assumption there wasn't a cooler. I didn't realize it had a secondary cooler. I face palmed hard on this one. The thing is it looks kinda hacked. There are two rubber lines at the break in the return line and they are attached by basic hose clamps on each end, not high pressure ones. The rubber lines were obviously cut with a knife or razor, not a hose cutting tool. A basic white zip tie holds them together and they float under the rad support. Don't mind the corrosion on the frame. It's still solid and i am working on descaling it. Then i'm going to apply KBS to everything i can get to and follow up with a good coating of Fluid Film... everywhere. There is no rust on cab, i replaced the front fenders, put a southern bed on it followed by a fresh paint job.

 

[RonD]

Trans cooler doesn't have high pressure, it has high flow, it's open at one end where fluid returns to the pan