After a recent off-road trip (8000' of very steep climbing and return), I pulled on the highway in my 99 4.2 4x4 and discovered it wouldn't shift into 2nd until very late (XL w/ no tach, but it was winding tight). All other functions of the trans operated normally. After a little research, I checked the 1-2 accumulator spring, which came out in two pieces. $10 for a new spring ($60 for new fluid as I drained the converter),the trans operates normally, and I preserve my record of having owned many vehicles in over 30 yrs. of driving and never have taken one to a shop for repair (other than for tires)! I shudder to think what a shop would charge for this repair. I hope this info helps someone else w/ a similar problem.

 

You probably saved yourself $1500. How hard was it to get to the spring?

 

To get to the 1-2 accumulator spring, all that has to be done is to remove the pan, remove a large snap ring which holds a small piston, remove the piston and the spring falls out. There are actually two springs separated by a piston ... the lower spring broke on my truck. Installing the spring was a little tricky, as you must hold the piston up to install the snap ring. I carefully pushed the piston up w/ a bottle jack in order to hold it while I installed the snap ring.

 

Punched the gas to jump across a busy 4-lane on a Friday afternoon, let off the gas just in time to catch a very rough 1-2 shift. When I got back on the gas I had to wind my 2001 F150 up tight to get a 2-3 shift. It's been that way for a couple of weeks. Sounds like the exact same symptom only from 2 to 3. Is the 2-3 acummulator similar? I'm a tightwad and the $10 spring sounds tempting however if I go to the trouble I think I would rather drop in a Factory_Tech valve body ($225). Since I regularly pull a trailer I've been considering the valve body for a while anyway. Any words of wisdom on this?

Just found out Factory Tech no longer carries 4R70W valve bodies. Called TransGo about a shift kit; they include the 1-2 spring but not the 2-3. Real nice guy on their customer service line though, said he is hearing more and more about broken 2-3 springs.

 

Keep in mind that I know almost nothing about transmissions, but I'm a pretty good troubleshooter and I can usually take something apart and put it back together correctly. Your 2-3 shift problem sounds very similiar to the problem I had. I saw there was a 2-3 accumulator w/ springs when I was researching my problem, but I didn't pay much attention to where it was located. I think it might be under the valve body, but that's just a guess based on when I was working on my problem I didn't see anything visible under the pan that looked like the 1-2 accumulator. If I had your problem, I would certainly investgate the 2-3 accumulator springs. It's a great feeling to fix a major problem with a inexpensive part.

 

Yup, the 2-3 accumulator assembly is under the valve body. If you suspect a problem then you have to drop the VB to check that out. There is a silver cap that is held in by 3 tabs and then the spring and the accumulator. I usually remove the 2-3 spring on the stuff I see. It will shift a little harder that way, but it can get rid of a slow 2-3 shift and is better for the transmission.

I honestly have never seen a broken 2-3 spring in the several hundred of these that I have been into. I don't know where he got that from. I am thinking it is just salesman talk. I have a box of these things that I have taken out and not a one has ever been broken.

Trans-go is definitely not my favorite for the 4R70W transmissions by the way. If you are curious as to why then I would go dig around on the mustang forums and ask those guys. A lot of history.

Darrin

 

I have a broken 2-3 spring right here next to my keyboard. Installed a shiftkit while I was into the tranny. By the way, the Transgo kit does not include a 2-3 replacement spring, however the TCI kit doesn't use a return spring so I went with TCI. Please note that the teflon split-ring with the TCI kit is next to impossible to get passed the snapring groove (working against a very heavy spring). Missed the overdrive band the first time and had to tear it all down again. Also note the guy I spoke with at Transgo said he had been hearing about broken 2-3 springs lately.