4r70w tranny shudder on 97

[schadler]

I know this has come up before, but I could not find a suitable answer to my dilemma in searching, so here goes:

I have a 97 stock V8 XLT with the 4r70w tranny. Dipstick recommends Mercon. I switched to Mobil 1 synthetic ATF at about 90k miles because it is both Mercon and Mercon V compatible. I'm at 120K and just developed a tranny shudder and some slip going from 4th to overdrive. I changed the fluid and filter again, using Mobil 1 again. This time I also did a drain to the TC, so 12 quarts total. THe shudder is still the same, although the drive is much smoother otherwise.

My 2 questions are, 1) Is Mobil 1 truly OK for 4r70w recommeding Mercon (not Mercon V)? and 2) can the problem be solved by adding a Ford friction modifier product? if so, what kind, and how much?

 

[stang99x]

Just use a mercon 5 compatible fluid. Modifier additives IMO aren't worth the effort. Although your vehicle did require merconIII/Dexron when built, ford revised the fluids to merconV later on. Take it and have it flushed. Sometimes a flush will push out small blockages that slow the flow

 

[schadler]

Just use a mercon 5 compatible fluid. Modifier additives IMO aren't worth the effort. Although your vehicle did require merconIII/Dexron when built, ford revised the fluids to merconV later on. Take it and have it flushed. Sometimes a flush will push out small blockages that slow the flow

Hmm, well, I just did a change that used 12 quarts of $6.35 ATF That, coupled with the fact that other posts suggest shudder is caused by fluid, band or solenoid problems (i.e. not a blockage), makes me leery to do a flush.

I saw somewhere that Glacier recommended an additive before servicing solenoids or doing a rebuild. I'd rather go that route first, but I need to know what additive. Anyone?? Glacier??

 

[schadler]

So I guess my question to the above was, does Mobil 1 ATF have the right friction modifiers, or do I need to add something?

 

[frickea86]

i would NOT reccomend you take your tranny to get it flushed, that would 9 times out of 10 make it worse seeing the milage on the tranny. There are many people running Mobil 1 Full Synthetic ATF fluid well before Mobil 1 certified it for mercon V and no problems that i've heard of. I would look for the problem elsewhere.

 

[stang99x]

120K is nothing. I have flushed trannies with well over 200K on them and never lost one. Especially if you have recently changed the fluid and filter, at which point you changed no more than 75% (if that) using the drain and fill, leaving 25% crappy fluid to recontaminate the nice new $7 a quart fluid.

 

[schadler]

120K is nothing. I have flushed trannies with well over 200K on them and never lost one. Especially if you have recently changed the fluid and filter, at which point you changed no more than 75% (if that) using the drain and fill, leaving 25% crappy fluid to recontaminate the nice new $7 a quart fluid.

The 4r70w holds 14 quarts tops. I put 12.5 back in. That's a 90% change. good enough for me.

I also don't believe that you MUST get all the old fluid out. Change intervals are designed in such a way that you are changing enough with a "normal" change (pan drop only) to meet the engineering specs. At least that's how it is with Mack trucks, where my brother engineers just that...change intervals. If it were a problem that some of the old oil stays in, it'd be a requirement to do flushes every 30K miles. You'd also see trannys blowing up after 50 K if that were true. I think flushes are a good idea, but certainly not required.

I appreciate your info/reassurance on the Mobil 1 ATF. Thanks Stang

 

[Glacier991]

The only additives I recommend are those made by Lubegard. But candidly, I am thinking you may have other issues going on. One initially may suspect the fluid in a shudder situation, because a major cause of shudder is an oil breakdown at the fluid interface... but that is not the only thing.

You might benefit from a VB rebuild. The 4R70W has a BUNCH of pressure ports, and pressure readings would be helpful as well. I'm think you have some low line pressure or some leaky spools in your VB.

So if you want to go from mild to wild, here is what I'd do..... try the lubegard supplement (go to any trans supply house, they will carry the lubegard products). At worst you have wasted $12. Will it do the trick? Probably not.... but, maybe ....and won't hurt anything.

Next if you feel inclined lets get some baseline pressures. If you can't or rather not.... then let's pull the VB and add a kit, and some sonnax additional upgrades and also replace the EPC (pretty cheap inthe 4R70W compared to the 4R55 and 5R55). You might want to do some of the mods I'll soon be posting the the 4R70W rebuild Diary to the VB as well. (I'm trying to coax Jerry W though a mutual friend into sharing some additional suggestions I might show.)

Hope that helps.

ps. Lastly you COULD have some issues with clutches or the TC... but I am thinking the above issues might solve it.

pps. There IS a circuit board add-on for the 4R70W that address shudder issues, but I need to find the info, and will post it. Might be a consideration. I think it affects modulation of the EPC and/or TCC. I have no first hand experience with it.

ppps... Although I do not think it is necessarily your issue, there IS a TSB that addresses shudder in the 97 4R70W (and maybe others) it is FORD TSB 97-08-08. The TSB that said they went to MercV in 98 is 97-21-10.


Glacier

 

[BrooklynBay]

The October 2006 issue of Gears has an advertisement on page 55 from a company called Compushift. They have an electronic transmission controller advertised for the 4R70W. Their website is WWW.Compushift.Com.

 

[stang99x]

If you want it to shift better, search online for "factory tech valve body"

Its a known f150 product, but I imagine it will work for you as the tranny is the same.

DId you clean the tranny cooler out? this is where most of the bad stuff resides over time, and fresh new fluid will pick it up and recirculate it. Local yards require proof of flushed lines and coolers for tranny warranty purposes. I'd just rather not see you loose the tranny.