2001 Chevrolet Tahoe 4x4, runs great, needs 3rd and 4th gear

2001 Chevrolet Tahoe LS Description

This is my wife's Chevrolet Tahoe LT. We are the 2nd owner, purchased in 2004. It is Black with heated tan leather seats. We really love this truck. It has been well cared for but like all Chevrolet trucks of this year it developed rusty brake lines. The truck only has 102,000 original miles on it, so I replaced all the brake lines, rotors and pads. It has the large 5.3 V8 engine and 4x4. I think it has almost every option, Tow package, sunroof, CD player and cassette.
Well, in January we were helping a friend move when we noticed a puddle under the truck. A red puddle, the transmission cooling line rusted and leaked. I replaced the line, and flushed the system, but when we got back on the road 3rd and 4th gear were gone. I have read that this is also a known issue with the Tahoe. We are putting it up for sale and if we get a fair offer it will be yours. It is still driveable up to about 45mph, so a test drive is an option. It really just needs the transmission repaired and it should be good for many years to come. We are on the fence about just going ahead and fixing it, because it has been very reliable and great on family trips. But we will offer it here and see if there is some who knows Chevy transmissions better than I do.