Contour Enthusiasts Group Archives Forums Modifications Transaxle CD4E harsh downshift under braking?

hey all, have any of you with atx's (cd4e) felt a very harsh downshift 2-1 under braking, it happens about 99% of the time and 50% of the time it is really noticeable/harsh. doenst seem as if it is hurting anything. fluid is new and level good. could be throttle hang when i accelarate hard then left off early(before redline) it will wait to upshift 2-3 seconds. could they be related. any info appreciated. i am a ford tech, still kind of if'y on trannys. my tranny guy at my shop would give me a wierd look if i told him this. i know you guys can help a fellow contour driver out.

1998 contour se/sport 2.5l CD4E, Reman trans, also has been out and resealed, new solenoid pack a while back.

thanx in advancea all!

I have heard of this harsh downshift, when the tranny is overheating.

Does it do this all the time or only after being driven for awhile?

Answering this will rule the overheating out or in.

yeah it seems more noticeable after it it warmed up. i had a problem when the tranny slipped for about 40 miles on the interstate. that ended up blowing out the pump seal and fluid and smoke all over the highway. got that fixed and its been flushed out 3 times since that 2 years ago. might have damaged the torque coverter and/or pump, overheating! doesnt seem to drive bad or anything i beat it pretty hard and havent had a problem since. a little slower cause my heavier 17" rims and bassani catback with resinators removed dropped some low/mid range torque.

Have you done the shift sensor replacement? Im told that the CD4E transmission has a bad shift sensor that causes hard shifts on occasion, and mainly from 1st to 2nd gear. But I dont know a lot about it as I have the MTX tranmission in my tour.

Mine does it sometimes too, very seldom though. It happens when i accelerate and some dumbass in front of me brakes and i have to brake fast not to crush. it's not very harsh, but you can feel it.

Inspect the tranny mounts first - might be a cheap fix...

Then consider an external tranny cooler. I'll defer to Unisys on this one - he has the superior knowledge in this department.

Check out TSB 98-13-11. Beside a new software load the Servo (can't remember name, the one that's accessed from the outside bottom of the tranny. That made a big difference, just last year I did replace the TSS sensor. Just like your issue it seemed to keep the throttle pulling and then do a 1-3 shift Mine was terribly harsh on the upshift, first time it happened was in traffic jam going around Chicago. Major Saftey issue IMHO after that snafu!!!!
It still gets confused at times (mainly after interstate driving then you get into traffic, after the ATX had learned those shift patterns for several hours is when it was at it's worst), but at least it's not trying to destroy itself.
Not sure if that makes sense but I don't know the FORD ATX lingo.
Paul
Software designers and the ATX designers need to talk more.

I've been wrestling with a CD4E in this Mystique for a couple months now. (See my "saga" in this same forum)
When you say it happens only under braking conditions, that brings something I learned this week to mind. One of the five solenoids in the pack bolted to the front of your valve body controls the lock-up torque converter. (TCC, or the MLUS as ford used to call it) This solenoid will lock up your torque converter in a very narrow band when your throttle position and torque load are just about even and it can save you some gas. Well there is one signal that will unlock it immeadiately, the BOO or brake on-off switch. Here's a test you can do. While holding your accelerator steady and driving at say a steady 55mph, lightly tap your break pedal, your rpms should raise by 300 - 500 for a few seconds, then fall back to where they were. If this doesn't happen, tho BOO sognal is not getting to your PCM for the TCC equation. Of course the TCC solenoid could be bad, but that should give you a code, and trouble at other times than just breaking.
Hope this helps.
Greg