The $2000 CLUNK!

[swissarmychainsaw]

Here is LilRed (1984 Silverado, 305/700R4 No AC):




I have had this truck about 4 years, and love it. It's a hobby truck, meaning it sits mostly and only gets out on long stretches for vacation or out dirt biking and stuff. (127K miles) It's all stock.

The trans has leaked the whole time I have owned it, something I know these 700R4s tend to do.
I have made pitty-pat repairs to the trans over the last few years, meaning I wasted money on not really fixing the leak, which is clear to me: It needs a rebuild.

I just took it on a three hour cruise towing a dirtbike trailer, and coming home, after dropping off and unloading everything I backed into a parking spot and BANG!

I stopped real fast, got out to inspect the damage. I was SURE I had either hit a car, or the telephone pole behind me. I got out, and I was about 4 feet away from the pole. Hrm...

I pulled forward, then put it into reverse again... Clunk (normal) then take my foot off the brake, give it a little gas, and BANG! there it is again!

The short version (although I might have passed that point already) is that in reverse it bangs like that every couple of feet? Needless to say I was not driving it around or anything after that.

It reminds me of when I broke the yolk in a van years ago, but that time the drive shaft ended up on the ground.

Drive shaft feels sold, feels like its in the tranny. The tranny has always felt messed up, so I'm happy to "fix" it. Did not downshift when you stomped it, felt like you had to floor it to keep it from shift really early.
The good side was it got really good gas mileage.

So my real question is this:
What do I do now?
I see 700R4 on Craigslist (here in San Fran area) for like $700 supposedly rebuilt already. Is that too good to be true?

Or do I have this one rebuilt, or do it myself.
I don't know jack about transmissions, but am a capable mechanic with the right manual, but don't have much time (three year old at home). I'm not broke though either.

I *would* like to make this truck a little bit more capable as a tow vehicle. Nothing crazy but I'm thinking not having it shift as quick would be good, maybe a cooler.

So if I go shopping for a transmission what do I look for?

It seems that the Torque Converter is what determines when the transmission shifts, i.e. where a "shift kit" goes, right?

Thoughts appreciated!
--Nick