bad pcs?

[_nick_]

hey new to the forum

my grand prix is fine these days but im posting about my 98 olds intrigue with the 4t65e. Im pretty sure i have the all-too-common faulty pcs. Basically the trans seems to shift ok when cold, but as it heats up the shifts start feeling really sloppy and weak. starting a few months back I noticed the trans beginning to slip/shudder on take-off when hot if the gear selector is in D,3,or 2...but it will not slip AT ALL if the shifter is pulled down to 1st to take off. I found this pretty odd...With the weak shifts it sometimes throws a p1811 and the shifts turn very firm and the slipping disappears but I generally have to drive it for several hours to get it to throw a p1811 and go into full line pressure... this sound like a bad pcs to you guys? what do you think about the take-off slipping in D,3,2 but no slipping in 1st? the car just locks up and goes if i manually take off in 1st!...but slips in higher gears? The trans automatically takes off in 1st anyway so whats the difference between the two?

Ive heard alot of success stores around lubegard additive, and i cant help but wonder if some of this stuff may help free up a stuck pcs? the fluid in the car is pretty clean..but who knows?

Is there any guide/tutorial on digging into the trans to get the side cover off? looks like the mounts have to come off and the engine hung on a pick to lower it down...

thanks in advance

[Trannyman95]

It does sound like you pcs is bad from what you are describing but you could also have some other problems which are causing low line pressure when hot. As far as having holding power in manual 1 here is why.... When you pull the shifter into manual 1 you have an additional band inside the transmission apply which gives more forward holding power ONLY in 1st and 2nd gear in each manual position, not in D or 3, and also the line pressure in 1st is upped dramatically by the pcm to not only keep this extra band applied but also because that band serves as engine braking for coast-down conditions such as going down a steep grade and letting the engine do the work instead of just your cars' brakes. When pulling down into manual 1 helps you take off from a stop then as a minimum you have a low pressure condition that is likely caused by more than just a faulty pressure control solenoid. Lubegaurd makes a great product but it isnt going to fix a poorly designed solenoid, which the only real fix is to replace it, but again that may not entirely fix your problem.

[_nick_]

thanks for the reply..

I was considering doing the pcs myself but i wonder if all the labor is worth while without going right in and replacing the 4th gear hub? My 4th gear still seems to work fine, and i do have nearly 200,000 miles on the car so my guess is the previous owner likely already replaced the 4th gear hub? As far as my experience goes it is very unlikely to get over 150,000 miles on the same 4th gear unless you just simply drove in 3rd all the time. I have a sneaking suspicion that the trans was overhauled at some point before I got it...but i have no clue.

[Trannyman95]

That is a lot of mileage for the trans to be original! Not too many make it that far for sure. Every different carline / engine / gearing combo seems to have a direct effect on the 4th clutch hub going bad. Some only make it to 70K, some with well over 100K dont look too bad, and just as you mention driving style and habits also have a large effect on the life of the shaft. If you are thinking of replacing the shaft then I would suggest installing a Transgo shift kit also as this will give you an upgraded boost valve and new pressure regulator valve spring that goes in the valve body as well as new accumulator springs to quicken up the shifts a bit. It is not a performance kit, just makes the trans work nicer in stock form and helps overcome some common problems.

[_nick_]

so if pulling down to manual 1 helps take off what other issues could i have other than a faulty pcs? The fluid was changed just before i got the car last fall (nice bright red colour) but I dont know if the filter was changed. Good idea to drop the pan and change the filter? maybe use synthetic fluid to re-fill?

[Trannyman95]

Clean red fluid doesnt mean the trans is in good condition and may have been in poor condition and was flushed to try to help or cover up a problem before you bought the car. Seals do wear and shrink over time and can also cause problems after the car is warmed up. If you plan to drop the pan and change the filter then just use Dexron 3 fluid in it and it will be fine since that is what it had before. A lot of people have had problems after switching to synthetics with these transmissions with slippage problems. If the trans is fresh then it is worth the cost but its not worth the extra money to hope it will help out a trans that isnt working properly.