2.3 liter, Automatic, 2005.

Drive & Reverse back and forth test works great. Shifts PERFECT between 1rst & 2nd. And into OverDrive. It seems to DOWNSHIFT from OverDrive, when needed and back into OD when done climbing a small incline.

When there is NO LOAD, the transmission shifts FINE all the way through. As soon as there is a load (incline or needed acceleration), 2nd and 3rd have an issue. There is a SPIKE in RPMs (500-800), then a KICK into gear. I need to note that there are NO LIGHTS. No check engine, no flashing O/D light.

The previous owner, from obvious wear and tear, did not maintain this truck and likely drove it pretty hard. I have owned the truck for three weeks now (if that). The entire undercarriage is covered in a light rust, likely from being beach parked. There is also a heavy, but not long lasting vibration from somewhere, JUST when taking off initially if I don't do so slowly.

TROUBLE SHOOTING:

When on an incline, if I let up the acceleration when I desire it to shift, it works and does so smoothly. On an incline, this sucks, as you lose momentum at the same time. On flat surface, this is especially handy to know.

Can anybody assist me? Getting estimates for fixing the issue just makes it hard to even know what direction to go in. Some already ASSUME it is worst case, so are they really going to look for a lesser cause? Others seem TOO cheap to be true!

WHAT I HAVE BEEN TOLD:

I took to FOUR shops.

SHOP1: We need to open your transmission and might as well rebuild for a grand total of $1,000.00. (Friend referred me here and they are a BBB member).

SHOP2: It might be the VALVEBODY ($1200.00) or a CLUTCH PLATE ($2800.00). (Seemingly Reputable Shop, Also BBB).

SHOP3: "Oh, if you are slipping between 2nd & 3rd, then you need a new or rebuilt transmission!" ($1999.99). (Seemingly Reputable Shop, Not BBB).

SHOP4: A junk yard has my transmission for $500.00, used, no rebuilt, 2 month warrantee and I have a friend to install it. My friend is a great mechanic, but does not rebuild trannies, but said he can put one in, no problem. And he will NOT charge me.

SUGGESTIONS????