1997 Mountaineer tranny

[vsmvj]

for some reason at 40 mph my tranny starts to vibrate

 

[vsmvj]

1997 Mountaineer 5.0

two problems, first where do I find the computer module and second at 40mph my transmission seems to struggle and shake or vibrate. If someone can help on these issues I would really apreciate it :fire:

 

[BrooklynBay]

Welcome to this forum! What makes you think that your transmission is the thing that is causing the vibration? Is it a shudder? Unbalanced tires usually create vibration at higher speeds. What type of fluid do you have in your transmision. The 5 speed 5R55E uses Mercon V. Other fluids would cause slippage, and shudder.

 

[Turdle]

The PCM module is in the passenger side firewall. Look for a big plug with about 100 wires going into it. Remove the 10 mm center bolt on plug, then the 2 11mm bolts on either side of it. PCM will slide out.

At about 40 mph the shift point for the overdrive
Does the OD off light flash?

 

[Glacier991]

It's also about the right point for convertor lockup

 

[performancenut]

When was the last transmission fluid change? Old fluid can contribute to a torque converter "Shutter" that can inprove with new fluid and some additive.

 

[Glacier991]

It "could" be a driveline issue as well.... U joint comes to mind.