Howdy everyone,
Anybody have any experience with the 4R70W transmission hunting between 3rd & 4th gear? The converter lockup seems to be working properly. It happens mostly around 40-50 MPH at light throttle. It's got a pile-o-miles on it, and the fluid hasn't been changed for quite a while. I plan on changing the fluid & filter
this weekend, and hopefully that will help. Anyone had this problem? Where can I find the Ford TSB's for this thing?

Thx!

 

First things first: refill it with Motorcraft MerconV - nothing else. Reuse the pan gasket but put in a new filter & I recommend adding a drain plug kit so it's not so messy next time.



Another good mod for that trans is the "forced lube mod". Click "NEXT" in the new window from that thumbnail to see how it's done.

TSBs are hard to come by, but you can start by searching Al's Links. If you can't find what you want, e-mail me. I have the '89-00 TSB CD.

 

Actually, one of the other Ford-Trucks website has a full set of TSBs online and available to the public.

Tranny hunting, especially into OD, can be due to a very high axle ratio that will exacerbate the problem. 3.08 and 3.27 ratios are particularly known for this.

Steve

 

Thanks guys....
It looks like it's the torque converter shudder problem that a lot of these have. I changed the fluid & filter, put in Mercon III, and it seems to be working ok, but it still shudders around 35-45 MPH. I have heard that the
Mercon V is supposed to help the shudder. I also found an additive that's supposed to eliminate the problem....."Shudder Fix". I'll have to try it & see if it works.

 

I Almost forgot.....
When I dropped the pan, there was a yellow, plastic plug with an O-ring on it, and a stem. Kinda like Cracker Jacks......goodies in the bottom.
I looked through the service manual, and couldn't find anything that looks like it, so I'm thinking it may be from assembly when it was new....??
Anybody seen this before?

Thanks again!

 

1. No mercon III, it's just mercon, but happens to be the same spec as dexron III.

2. Thats the wrong fluid for the 4R70w. It needs Mercon V which has the friction modifiers needed. Which was stated above as the correct fluid.

3. Yup, just the seal that gets pushed in when the dipstick is added on the assembly line.

Adrianspeeder

 

If you want lots of info on the 4R70W go to the articles here and do a LOT of reading:
http://www.tccoa.com/articles/tranny/index.html

I had shudder problems too. Dropped the pan, cleaned out valve body, did the jerry mod, new mercon V, drain plug kit, BIG B&M plate style tranny cooler inline after factory cooler. Nice firm shifts, never a problem since 60,000 miles and tranny fluid almost looks like new. Time for a change now.

Biggest problem with 4R70W is inadequate OE cooler. 20-30k miles and fluid is burnt.

 

Hey, thanks a bunch y'all...I appreciate your help.
I wasn't able to flush the cooler/lines, but since I changed the fluid & Filter,
I'll just drain the oil & refill with Mercon V. The service manual said something about starting the engine with the cooler lines disconnected....I don't feel good about doing that with a tranny that has 173k on it (and never been serviced!!). The new oil should do the trick. Again, thanks for all your input.

 

Fill it slowly. Go 5-6 quarts (max on dipstick). Start it up in neutral or park for 20-30 secs. Then fill more. Need to do this maybe 3-4 times. Otherwise you'll overfill it and it'll pour out the dipstick tube. You'll think it's full but it's not.