slowlane
Junior Member
- Joined
- Nov 1, 2014
- Posts
- 22
- Reaction score
- 12
- Location
- New Hampshire
- First Name
- Tim
- Truck Year
- 1985
- Truck Model
- C20
- Engine Size
- 350
Hello,
I recently changed the fluid and filter in my '85 C20's Th400. The old fluid was pretty decent, maybe a little dark, but not burned up looking. I filled it with 6 quarts per the shop manual. Now when I first start it in the morning there is a whining coming from the converter/pump area of the trans. The whine goes away after several seconds and is quiet for the remainder of the drive. I pulled the trans dipstick one morning before starting the truck and the fluid level was an inch and a half or so above the full mark. After starting and driving it a while I checked the level again and it was now right where it should be. It seems like the fluid is somehow draining from the converter back into the trans while sitting overnight. The transmission shifts good and exhibits no other symptoms. I am not real familiar with the inner workings of automatic transmissions. Any thoughts?
Thanks,
Tim
I recently changed the fluid and filter in my '85 C20's Th400. The old fluid was pretty decent, maybe a little dark, but not burned up looking. I filled it with 6 quarts per the shop manual. Now when I first start it in the morning there is a whining coming from the converter/pump area of the trans. The whine goes away after several seconds and is quiet for the remainder of the drive. I pulled the trans dipstick one morning before starting the truck and the fluid level was an inch and a half or so above the full mark. After starting and driving it a while I checked the level again and it was now right where it should be. It seems like the fluid is somehow draining from the converter back into the trans while sitting overnight. The transmission shifts good and exhibits no other symptoms. I am not real familiar with the inner workings of automatic transmissions. Any thoughts?
Thanks,
Tim
