TC lockup unlocking or slipping? 2000 GT

[AB 92LX]

When cruising or light acceleration in drive (3rd) at low RPMs (1500), the lockup is either repeatedly unlocking and locking or possibly slipping. Giving the car more throttle causes the lockup to lock and stay locked so I really doubt it is slipping. Also when cruising on the highway, giving the car a little more throttle, then letting off to same cruise position causes the lockup to unlock momentarily. At any time, giving the car more throttle causes the lock up to lock and stay locked.

Car is all stock with 46K. I have disconnected the battery to reset everything, no help.
Any thoughts? Could a flat spot in the TPS cause this?

 

[Lookin4Stang]

First sign of tranny misbehavior I always check the ATF level. Are you low, high?

 

[chuck943]

Do u mean its shuddering?
TC will unlock when u decel,when it gets a brake signal,and when u accel, it only locks when at a steady cruise and load is stabilized.
If it is shuddering like running over rumble strips in road, sometimes having a tranny flush will cure it(varnish builds up on clutch disc in TC ,and new fluid acts like a solvent and disolves it). If not replacing the TC solenoid and the plastic wire loom in trans that hooks to solenoids usually cures it on this tranny.

 

[nyuk98gt]

AB 92LX:

+1 for what "chuck943" said. If the fluid and filter are old, change them. ATF ought to be changed more often than the Owner's Manual says (just like we change our motor oil more often than the schedule says).

As long as the car hasn't been abused, your description sounds pretty normal. I can tell you that my stock tune (SXA2 / BAI1) had some odd things in terms of the shift and lock schedules. With the good old Pro Racer software from SCT, I have the shifts and locks/unlocks where they should be. A good tuner that knows the 4R70W is worth his weight in gold, imo.

You might consider an ATF cooler along with the j-mod even for 100% stock car. Read all about it at TCCoA.com in the Tech Article/Transmissions section and the required reading is "Transmissions 101".

HTH,

Chris

 

[crod99]

tcc shudder is considered a normal concern in our cars due in part to the shift schedule it can be fixed in a tune if it is not mechanical . I would reccomend you go to ford and pick up a 5 oz container if friction modifier for your rear end . pour the whole bottle in and drive it for about 100 miles this will help as this is considered a fix by ford . what you are feeling is the clutches in the tc are dry and are not getting enough lube due to burnt or worn out fluid the friction modifier works well in most cases if it does not fix it you will need a tc > my .02 Chris

 

[CobraRed_96_GT]

TC shudder is very common w/ the 4R70W as said, supposidly the new Mercron V is supposed to help the ford shudder specifically. I needed a rebuild, but not just due to my TC. The tranny cooler is a must.

 

[Mike97gt]

This could also be a misfire concern. Misifres tend to be very noticable at high load low rpm's such as when the converter is locked..

If it does this going uphill with the converter locked then it's most likely a misfire concern.

out of 1,000 times I have read what you are complaining about on a repair order 999 times it's a misfire caused by plugs/wires/coil

 

[CobraRed_96_GT]

This could also be a misfire concern. Misifres tend to be very noticable at high load low rpm's such as when the converter is locked..

If it does this going uphill with the converter locked then it's most likely a misfire concern.

out of 1,000 times I have read what you are complaining about on a repair order 999 times it's a misfire caused by plugs/wires/coil

this is also a very good point, when i first had a sparkplug go out when i first got my car i thought it was a drivetrain issue