95 Exp EB 4x4 reluctant to shift out of 1st

[rcaligan]

I have a 1995 Explorer V6 4x4 Eddie Bauer, 120K miles, about 60K miles on this tranny. OD OFF light blinks. When accelerating, it will not upshift out of 1st gear unless I take my foot off the accelerator. Upon reaching 2nd gear, it easily downshifts back into 1st unless I'm very light on the acceleration. Once I build up some speed it'll stay in 2nd, and if I continue accelerating it'll shift through 3rd and OD normally, even under heavy acceleration. This happens whether the tranny is hot or cold.

Sidenote: About a year before this problem the truck ran rough on startup one morning, the CEL came on and the OD OFF light started blinking. I had the tranny code pulled and he said it was a bad VSS. The rough start problem went away and I pulled the neg cable to clear the CEL, the OD OFF light went off, too.

Could that have been a warning that the VSS was dying, and now it has finally died?

 

[rcaligan]

Update

Had the codes pulled today:

335 - Pressure feedback EGR sensor voltage out-of-range
646 - Incorrect gear ratio obtained for 2nd gear
647 - Incorrect gear ratio obtained for 3rd gear

I should also add that the check engine light is NOT on (although it does work).

Can anyone help?

 

[rcaligan]

Anyone?

Any help at all?

 

[rcaligan]

The dealership says...

I took it to a dealer for diagnostics, and here's what he recommended:

- Intermediate and overdrive pistons need replacing.
- New PCM.
- And of course with that comes dropping the pan, new filter & gasket.

Now a few years ago I changed some servos on the right side of the tranny, and I didn't have to drop the pan to do it. I did have to pull off the cat. converter and a heat shield to get at them, though. Are the servos I changed and the pistons he wants to change the same thing?

He also mentioned that he will inspect the "bands" and see if they need replacing.

Does this make sense?