Thread: 4T65E Hard Shift-Solution

Like I stated previously, the weather around here has been VERY hot and the transmission still has not hardshfited once now in months of use with the ZZP towels and the 2 18,000 GVW coolers. It has been shifting perfect despite the very hot weather with the A/C running almost constantly although on a recent run at night with cooler weather and no A/C on, still no hard shift issue. There is no question that the shift kit and coolers have resolved the issue. When you look at the cost of the kit at around $30 and the double stack Long cooler for about $50 each, for me, the whole job was a little more than $100 (definitely with 1 1.5 inch double stack 28,000 GVW cooler). I don't count the Dex VI and filter since that would have to be done at some point no matter what and is a regular maintenance item either way and just insurance on any tranny regardless of this install-good insurance. My fluid has been well maintained but I plan on going back to my old transmission fluid schedule from now on with the 4T65E of about every 20,000 miles or 3 years which ever is shorter than I had been doing before the problem surfaced (please read the beginning of the thread for specifics). It appears that for everyday use the 4T65E's shortcomings are very hot running temperatures along with weak accumulator springs. Glad it worked for another poor victim of the 4T65E hard shift issue!

Pardon me for clarifying further.

Its just that I started experiencing the HardShift, or what the GM Mechanics call it as Shift Shock. They recommend that I replace the whole transmission, which is totally crazy. I told them i dont this the problem is the whole transmission just because they are lazy to look for the problem.

Well, anyway, our problem with our 2004 Chevrolet Venture (that according to most forums have this tranny as the standard model) started about 2 months ago when the following where done:

1) Re-installed the Thermostat by the Temperature sensor since this was removed 2 years ago.
2) Changed the ATF at 70,000KM, and the Transmission Filter.

They told me that the Venture normally does get the Hardshift/shiftshock after the ATF and filter gets replaced. They used, what i assumed to be a certified ATF brand.

Reading up on forums, i found that the shortterm solution would be to turn off the engine for about a minute. This method works for me everytime. BUt we do notice that the hardshift/shiftshock is happening more often than before.

We live in the Philippines, where the temperature averages at about 32C. The Temp guage would after read at the range of 90-92.5 to 100C on a hot day.

I am glad that there are forums such as these that exist for us GM consumers.

So I guess these are our problems:

Pressure Control Solenoid
Mass Airflow Sensor

That can be solved by NOT replacing the PCS and MAF sensor. But rather the installation of the 1 1.5 inch double stack 28,000 GVW cooler and the ZPP Shift Kit

May i ask for more info on the following?

What does the ZPP Shift Kit look like? Because there are the two things that came up from my browsing:

http://www.grandprixforums.net/shift_kit.php

http://www.zzperformance.com/products_img/570_1.jpg

And may i also know how to install and where in the tranny do i connect the Cooler? TRANSMISSION COOLER, 28,000 GVW, NEW: eBay Motors (item 2453082364 end time Sep-02-10 16:17:27 PDT)



Im sorry for revisiting the questions. Its just that we are so frustrated with our Minivan already because we just recently had the Driveshaft replaced, and the left lower arm, because the lowearm broke off from its welding point, thus pulling out the CVjoint. Plus countless expensive repairs like the engine electrical harness, radiator fans and aircon compressor.

Thank you so much for your assistance.