4R70W Tranny Question

[jamied]

Greetings fellow F150 owners! I am new to this board, so I hope that I will be able to elicit a response or two...... Here's the problem: My one owner '97 SCab Lariat has over 162,000 (mostly highway) miles. It has never been in the shop for a major repair, and as a matter of fact I just replaced the front brake linings for the first time last week! Anyhow, back in '98 @ about 37,000 (just out of warranty) the transmission started acting really wierd. If its cold outside (60 degrees is cold in Mississippi), the transmission will not shift out of 2nd UNLESS one of 2 things happen - 1) run up to about 3500 RPM in 2nd and let off the gas suddenly (I call this tactic "pulling" it into 3rd) or 2) keep my foot in the gas and eventually the transmission will slip (RPM's jump way up) and then it will SLAM into 3rd. Since it doesn't get cold in Mississippi very often, this did not present much of a problem at first. Then at about 75,000 it started doing the shudder thing that seems to be commonplace with these vehicles. I changed the fluid and filter (did not change the t/c fluid as I was not privvy to the plug trick at the time), and everything was fine. Three years ago, @ about 120,000 the O/D switch stopped working. I don't pull trailers very often, so I rarely had need to push that button - so it could have been like that for a while and I wouldn't have known it. Then year before last I let the truck sit for about 2 weeks while I was out of town. When I got in it and fired it up, the O/D light was flashing, and a few hours later the battery went dead. I replaced the battery, and the light was no longer flashing, and the switch was still not working. Over the last year or two the shifting problem has begun to get worse, but only the first cycle or so through the gears. Once it's had a chance to warm up, everything is fine. I'm wondering what the heck is wrong with this thing...... I have already purchased a new tranny filter and will be installing it this weekend. Does anyone think that using Mercon V will help? I have read that you can use Mercon V in older transmissions, but you cannot use MerconIII/Dexron in a Mercon V transmission. What about a shift kit? I really can't afford a new transmission, so any suggestions would be highly appreciated.

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[Wombat]

Sounds like it needs another fluid change (in the torque converter too) and maybe a tune-up. The bands probably need adjusting. I would check around to see who is a reputable shop and you may still have to go to a dealer.

[ucfperspicere]

I agree. Sounds like that tranny's ready for a tune-up, or at least a thorough fluid change with nice fluid. If you wanted to get a shift kit, I've heard good things about Factory Tech Valve Bodies. I'd like to get one as soon as I have the money. From what I hear they're in the $200 range (try finding a member named Factory_Tech in the member directory and shoot him an e-mail for your price).

If you get one of these and don't feel comfortable installing it yourself, you can bring it to a tranny shop when you have your fluid changed and they'll do it for you. Not sure exactly how much money you have to spend, but a new valve body and good fluid change will be much cheaper than a new transmission, especially if you do it yourself.

Good luck.