4R100 Transmission Issues?

2004 FORD F-450
264,339 MILES • 6.8L • V10 • 4WD • AUTOMATIC
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SAM MUSSELMAN
  • MEMBER
  • 36 POSTS
I just recently had a new transmission installed. When you first turn on the truck and put it in reverse everything is nice and smooth but after you drive in a while when the fluid gets hot sometimes it’s very difficult for the truck to go into reverse. I did have some previous issues with a leak and a prior mechanic did put too much fluid into it. My question is, can a quart or two over the full limit, cause the transmission not to want to go into reverse?
Apr 5, 2025 at 5:32 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,193 POSTS
  • ASE Certified Mechanic
Hi,

Transmission fluid expands when it gets hot. That is why checking the level is done with the engine running and at operating temperature.

In theory, it could affect how it functions. That is where I would recommend starting to check. Drain the overage until it is full when hot.

Also, if the transmission cooler wasn't flushed, that is another consideration.

Try this and let us know the results.

Take care,

Joe

Apr 5, 2025 at 6:27 PM
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