Thread: Trans problems...Tuning out TCC lockup?

I didn't know where this thread would belong lol Transmission or Tuning?

My trans is acting up. TCC won't stay locked in 3rd or 4th gear. TCC goes to lock but it never fully gets to 0 slip. It oscolates back and forth between 30 slip and about 130 slip. Creates a sort of surging and bucking feeling as it locks and unlocks. Kind of harsh when it tries to engage too.

Trans shifts perfectly, fluid is full and clean. No other problems at all, the gears aren't slipping at all! I realize it's probably the TCC or PC solenoids or a leak in the valve body, but that's an expensive repair. I'm gonna try to clean the MAF and reset the PCM but I wanna have a backup plan.

So to get to the question: I have DHP, what can I change in my tune to stop TCC lockup all together? Get completely rid it, I know my mileage will be worse but I wanna avoid a rebuild as long as possible.

Just raise the lock up speed to the max.

mine did a 200 rpm surge light on the gas in 3 rd gear, did that for a month or so then one day i just had no 3 rd gear.

swapped in a used tranny.

Also, they can never be 100% slip free. The vehicles weight, the speed and the stall speed of the converter will determine the slip. In lock up it's still going to have a minor slip.

I understand it will always slip a tad but this is a noticeable lock/unlock and repeat that it's doing. I just wanna make it last as long as possible before I gotta replace something.

So all I gotta do is raise lockup speed to maximum and it won't lock anymore? Because 3rd gear is fine, just 3rd with converter locked is troublesome

Same thing with 4th, only when it locks does it give me a problem

Your normal slip is going I be around 20-40 at light cruise on level ground when you climb a hill or something it's going to go into the 100's depending on load. Now if you are steady state and it is just occilating then set everything to stock and see if it's your tune or a trans problem.

I've had this same problem before, I actually "fixed" it the other way around.... increased the minimum TCC duty cycle value across the entire table. Makes the TCC lockup harsher, but would lock and stay locked. I did this in HP tuners, not sure about DHP.

Did it actually "fix" the problem? You didn't lose anything later on?

I didn't lose any gears, if that's what you mean. Car clocked 300K+ on the factory engine/trans before I sold it. Shame that the Michigan body was rusted to ****.

its probably the AFL oscillating in its bore due to wear, it can be minimized if you remove the slip and program for 100% TCC duty cycle, it will remove the varied fluid pressure/volume changes and minimize occilation, easing up and then getting back into it a hair more might increase the occilation.

as an aside, ive found that i can increase the life of a marginal trans by deleteing p0730/etc to keep the trans from going into limp mode with the pressures jacked and greatly increasing the harshness/slamming.

ive killed two stock tranny's keeping it, when this trans started doing the occilation and delayed/slamming 1st, i set to not reporting, so far the trans has lasted over a year, the others had dies within 3-6 months of trans adaptives...

Wow that's pretty impressive haha

Okay, I eliminated all TCC lockup. Took for a test drive, it doesn't attempt to lock anymore and the gear changes are still fine!

HOWEVER, I think by doing that I also narrowed down what the true issue was. When I just cruise, it has "hickups" where the TCC starts to engage for 1 sec and then doesn't. I think this narrows it down to a solenoid. Gonna look into it further in a few weeks. At least now it's drivable and civil on the road haha

Originally Posted by Turbocharged400sbc

its probably the AFL oscillating in its bore due to wear, it can be minimized if you remove the slip and program for 100% TCC duty cycle, it will remove the varied fluid pressure/volume changes and minimize occilation, easing up and then getting back into it a hair more might increase the occilation.

as an aside, ive found that i can increase the life of a marginal trans by deleteing p0730/etc to keep the trans from going into limp mode with the pressures jacked and greatly increasing the harshness/slamming.

ive killed two stock tranny's keeping it, when this trans started doing the occilation and delayed/slamming 1st, i set to not reporting, so far the trans has lasted over a year, the others had dies within 3-6 months of trans adaptives...

Good info... I always had good luck increasing the TCC duty cycle, never knew why exactly it worked before. Personally, I like increasing it even if I don't have an issue... somewhere around 40-45% minimum and 100% maximum across the board.

Found any workarounds for the delayed engagement "slamming 1st" issue? So far, I have not.

no but mine doesnt do it nearly as often with the trans codes not reporting

Originally Posted by Turbocharged400sbc

no but mine doesnt do it nearly as often with the trans codes not reporting

Really? I don't have any transmission codes popping up in HPT, so I didn't think I'd benefit from disabling them. The delayed engagement seems to come and go on it's own. I can always try disabling them and see if it makes any difference. Thanks.