Hey guys, I know not strictly relevent, but you guys are pretty handy with transmissions and its is the same as offered in an F150 / ex' and others so here goes. Just bought a 96 T-bird 220k owner claims trans was rebuilt 10k ago by a reputable builder, i know the guy, but havent been able to confirm he did the rebuild. It shifts great, especially when cold and the converter doesnt lock. Once its warmed up, the shifts themselves are good, but the converter is being odd. It will lock in 3rd when doing 25mph, which lugs engine of course, and makes driving pretty jerky. When accelerating, its almost as if the converter is unlocking on the upshift, and locks right after the next gear engages. This creates the effect of a "double shift". Makes the car surge oddly, similar to a standard where right after you shift, you hit the gas, let off, then apply throttle normally. The converter lockup seems really harsh, it slips for a sec then just grabs, like slipping the clutch from a start, and just dumping it before up to speed. This is terribly hard to explain, i apologize for rambling. If you guys can point me in the right direction i would appreciate it. Would go straight to a shop with it, but nearest trans shop is 160 miles, and none are open on my days off. Further more i cant really be without the vehicle unless i must, so would like to order whatever i need and fix it myself if possible.

 

The first thing to do is to check for codes.

 

Did, had friend stick scanner on, nothing, my bad guess i probably should have mentioned that, i spaced it. He was getting an error message on it though so i guess it maybe didnt work? The things are over my head.

 

There should be codes stored if it isn't locking.

We can still fix it without codes, but it's the expensive way to do it. I'll list all the things it could possibly be and you'll buy them and see if any of them fix the problem. With the codes I can usually narrow it down to what is causing the problem.

Find someone that really can read the codes. The places that read codes free CANNOT read these codes. You need either a good independent shop or a Ford dealer.

 

Oh, i thought it just had to be a obd1 or 2 scanner, his is just a cheap one he bought for his jeep. Ill see if i can get them pulled next time im in town. There are no lights on in the car, od lockout works great etc, just to be clear.

 

I suggest you download a software called Forscan. It is free and has almost all functionality of IDS. The transmission coverage is excellent, good enough to show all Trans Parameters as gauges. Does bi-directional too. You can buy an Inexpensive OBD adapter to use it with, BAFX brand from Amazon is one, but there are many others. It will cover 94+ V8 Tbirds (and any Ford, even what is on the showroom floor now).

Download FORScan

 

PS. As for your trans issue (I had many of these trans, and I have a 95 bird).

Read codes as suggested.

1) Check fluid level and quality, ONLY use Mercon V.
2) Check MLPS, either using a DMM or thru Forscan, it may show voltage
3) Eliminate any torque converter shudder issues.
4) Make sure there are no misfires, bad coils, EGR, MAF, fuel trim issues (via forscan). Monitor misfires on each cy;l
5) Verify filter isn't floating in the pan (yes this happens with the 4R70W, ford saved a penny on a bolt)
6) Try Lubegard Red or Dr. Tranny Shudder fixx. You can research those products.

 

Thanks for the advice, the engine runs flawless, guy i got it from just had it smogged and the result was excellent. Only issue with the engine, is when the converter locks up at excessively low speed and brings the engine down to 900-1000 rpm it will ping unless i manually downshift. Ill try to get the codes again, i initially was thinking you guys would just tell me its a bad converter or something. Also didnt know when and where the converter should lock, never seen a electric auto lock in below 35 before. Wasnt sure if a programmer would help or not.

 

If you don't see a flashing OD light, a code probably isn't stored. You could use the Forscan app to monitor all TransPIDs. You can see when the solenoids are commanded, gear commanded, and check if everything is matching up.
You could also set and unset lockup.

I hate to say bad converter, these things are very hard to kill. My Tbird has the original trans, and I'm not easy on that car. It gets Mercon V every 30K, and there is a cooler. I use shudder fix and Lubegard red. You mentioned "Jerky," what happens if you touch the brake? If it cures it, additives or a full fluid change may help.



You mentioned pinging, try a higher octane gas.

 

Ill try the brake didnt think about it. I know for the E40D if you turn the hazzards on it will keep the converter from locking, made no difference in the t-bird.

 

Touching the brake will unlock the converter. If that makes the herkey herkey go away change the fluid. Not just the fluid in the pan, but all if the fluid.

I had a very bad shudder on lockup in my 95 tbird when I bought it. Got a good deal on the car because of it. A full fluid exchange with 16 quarts of full synthetic trans fluid and I haven't had a shudder since. (Burned a couple extra quarts of fluid during the exchange to make sure we got all the old fluid out)

Your lockup schedule matches mine in my 95. The programming on the early 4r70's are truly horrid. It will lock up real early in 3rd and bog the engine down to 1000rpm or less. Then when you tip in the throttle it will let the converter clutch slip a few hundred rpm for a few seconds and then re-lock the converter. This is pretty normal for these early generation electronic transmissions it is actually doing what it is being told to do.

If forscan can fix some of this then I might get what is needed and reprogram mine.....

JMO, but there is no need for any additives in the fluid. Just use a mercon v or full synthetic which says it is rated for mercon or mercon v and you will be fine.

 

Forscan can't correct anything, but it can give you a total picture of what is going on. TQ shudder feels like going over train tracks. Happens at about 40MPH. It has to do with converter wear and friction modifiers. New fluid helps, but mine needs shudder fix to completely go away.

An external cooler too, it is actually suggested(required) by Ford for the hotter states in a TSB. If you are going to do any hard driving, it is a requirement. If you want to keep it long term I would strongly suggest it.


Finally, the 96 has a revised calibration for the trans. You could actually goto a dealer and have it flashed in. Forscan can't flash older cars. You have to buy an IDS, there are clones around but it can become tricky to get one that can actually consummate a flash.

 

Torque converter shudder is actually caused by the ATF wearing, not the converter clutch wearing. If the shudder is allowed to continue long enough it will damage the converter clutch.

 

Do you think a Coyote/6r80 swap would fix it?

I might check into a reflash with the updated programming for mine. There's a good independent shop i know that can do all updates. Probably better luck there than trying to get a dealer to tell a 95 that it is a 96. I've never found dealers to be willing to think outside the box.

Actually, if I could make it think it was a 99 f150 4x2 4.6/4r70 I'd be extremely happy. That was the best programmed combo I've ever driven. They actually got it right with that one - it just did what it needed to do and did it right every single time.

 

If I flush 16qts of fluid, the 95 bird will still shudder (maybe once a trip) until I add the shudder fixx. Ford does suggest a cooler in their TSB in southern areas (and supposedly would install it under warranty long ago) for these issues, even with Mercon V. Guess the cooler keeps the fluid from wearing out quickly.

So you are saying once the converter clutch is worn fluid wont help?

I always thought friction modifiers are like wetting your fingers to turn pages. Dry fingers will slip, but a bit of moisture(which seems more slippery) will actually engage. The converter clutch pushes up against the TQ shell and either has to positively engage or not. I think also these 4R70W use a pulse PWM strategy to save gas. So it allows some slipping, but it can't bind, and that causes shudder. The friction modifiers coat the surfaces allowing this smooth slipping, and get "wiped or squeezed off" when engagement is necessary.

I may be wrong, but I think that is what is going on.

I just recently installed the carbon fiber diff into the Explorer. I bought 75W140 that supposedly had the friction modifier. Until I added the Ford Green Friction modifier product it would skip a bit at low speed. I believe the modifier sets a "digital threshold" to either engage or slide.

I think the converter is the same idea.