I just changed my tranny fluid in my '97 4R70W about 600 miles ago. Initially the 35-40 mph shudder was solved, but now it is back and worse than ever. I used AAMCO Mercon V synthetic blend. I drianed both the pan and the TC replacing just under 12 quarts of fluid. I tranny went 100k miles prior to fluid/filter change.

Is there anything else I can do to solve the TC shudder?
Is it safe to flush the tranny now that I have dumped all the old fluid, changed the filter and cleaned the magnet?

 

You can try the flush if you want but you may end up having to get a new TC to get rid of it.

 

There are a couple of additives you can add to the ATF to help with shudder. I had mine flushed about 800-1000miles ago and they refilled mine with regular Mercon and an additive ( Shudder Fix, I think) seems to have helped at least a little.

 

Shudder: some get the computer reflashed, some can be addressed by the aftermarket (shift kit and Sonnax valves), and the additive is "Lubeguard".
www.lubeguard.com/automotive/index_trans.html

 

Max
That's the product they used exactly. I knew it was called something Shudder Fix. I also talked to the dealer about adding in the Mercon V fluid and he told me they have/used additives to bring Mercon/Dextron to Mercon V specs so apparently they used Lubeguards products. I thought it was kinda BS'ing me about being able to change Dextron III to any other type of fluid.

If you don't mind I still have some questions for you or anyone else that can answer.
When dealing with reflash for the transmission what all do they change? I assume what they reflash is the tranny section (table) of the PCM. Do they just update that one PCM section or do they update the entire calibration code to a newer code?
Does installing a shift kit effect this calbration any? Meaning should I install my shift kit before they do a reflash (of corse telling them I have a shift kit) or does it matter.
Thanks

 

Hello KYFordFreak, I could'nt tell you if they flash the entire program or just the parameters for the tranny but I would sugggest that you do the shift kit or the reflash with enough time in between the two to tell if one or the other was more effective.

I dont think that having a shift kit would call for any changes in the flash cuz they are designed to work with the stock program. Even the chip will work well along with shift kits that are installed with moderate settings. What I'm trying to say is do either one first but give yourself enough time to rack up some miles and observe the changes (if any) each one makes independently before moving on to the next.

Hopefully one or the other will help. Do them separately and you'll know which one it was that worked for you.

Good luck.

 

RE: Reflashing...They run your vin number through and see if any TSBs have been issued for your model. If so, based on your computer code, they change it; it could be any updated with the entire program. Generally it would be transmission related, but if they made an "idle" changes for example, you get that too. If they do that, you get a new code and a sticker placed where the other stickers were and you get that code from there on out. The shift kit doesn't approach things electronically. The shift kit/upgrade that I was referring to for a shudder approach is the Sonnax Bypass Clutch Control Valve. The shift kit and/or the Sonnax valves will work fine with any code and will not be affected if you change codes after a shift kit install. Having your computer code reflashed to a new code does affect the Superchip; it has to be calibrated to "EACH" code.

 

Max and Le pew
Thanks, you both confirmed what i thought but wasn't sure about. I know the supership is "code" dependent and if I had one would have to be reflashed. I just didn't know if they would only reflash the tranny program as that is where the problem might be. They might run into one snag on my truck and that is it has been reflashed before by a previous owner. From what I have heard from a dealership is that early models like mine (production of 1/96) were having problems and the solution was a updated PCM program. They did the service right by placing the "Notice of Modification" authorized by Ford under the hood but by the time I got the truck it was unreadable. I assume the door jamb sticker is the OE one. I could look at the PCM and see to what it says also. I assume/hope that they have this info stored somewhere on a database. I hope it was not just kept at a dealer level or I might have great pains trying to track down what dealer did the reflash.
Thanks for the warning about doing more than one thing at a time. I always like/want to test things out indivisually to see what really changes. That's why I'm giving this tranny flush and shudder fix at least 1000 miles, to see what happens.
Thanks again guys.

 

Not to worry. The information on what is in your PCM is stored in the PCM. The tool that does the reflash reads what is in the PCM and picks the correct update based on that information.

The entire program is reflashed, not just the transmission.

Mark

 

What's the chance I could just have them read the calbration off to me for a smaller fee. That way I could have Mike at Superchips program the chip the way I need it to be and he could also improve on several points that a factory program will not/ can not do. It would deffinetly be cheaper than having to have them recalibrate the PCM and then buy a superchip. I'm just trying to sort out every possible thing I can. Thanks

 

I would think that the reflash and code would show up on the OASIS report. Might be worth a shot.

 

Ok, so now I might be able to find what I need on a OASIS report. I read somewhere before that OASIS report only covers like the last year or so. Any dealer should be able to pull one up right? If it was authorized by Ford there has to be a record somewhere. Allthough a reflash of the PCM might help in my pinging and shifting problems.

 

I had to dig this old thread back out just to let everybody know how it went.

There was some concern because I had gone so many mile w/o any tranny service.

While the TC shutter did get worse for a while after the change to Ammco mercon V, it eventually went away. My truck now has around 116k miles & the transmission runs like new. I'm almost ready for another fluid change.