Thread: Pressure Control Solenoid(EPC), TCC, 4th Clutch Hub Replacement in the Vehicle.

Well since I'm getting tired of having low trans line pressure after it warms up, I think I'm going to get in there and change the PCS myself. Before the shift kit, I was experiencing very slow shifts after it warmed up, and soon after Max Adapt set in causing all gears to slam, even torque converter lockup. The shift kit fixed those 1-3 shifts(and eliminated max adapt), but I want my lockup to be quick as well. I also just want my trans pressure to be correct, bottom line. Lower isn't good. I have looked up many posts on many different sites on how to replace it, most people say it's labor intensive but every explanation I see makes it seem fairly easy. I've dropped subframes a few inches and removed engine/trans mounts, I've removed ball joints to remove CV axles, I've done a trans fluid change and had the confidence to do a shift kit. So basically it doesn't seem like much of a hard job to me. I'll probably spend a day on it though being my first time. Any tips or advice before I order the part and replace it? Like:

1. Anything else I should replace while I've got access to the valve body?

• Side cover gasket?
• TCC solenoid? (Part#: 77942)
• Boost valve? (I have a boost valve from my TransGo shift kit btw)
• 4th clutch hub? (Aftermarket(heat treated) #84860C)

2. Any other things that are hard to do?
3. As far as I know the pcs is visible and replaceable after the side cover is off. I know I have to remove the bolts on the P/S rack to drop the subframe.

4. And how about parts? Should I just get an AcDelco part? It's part#: 10478146 for the 98-02 pcs. I found it for about $31 on amazon.
Amazon.com: ACDelco 10478146 Pressure Control Solenoid: Automotive


This forum shows in detail how to gain access to the side cover: GM 4T65E solenoid shift valve replacement TCC/PWM EPC 1-2 2-3
Very thorough write-up on how to replace the 4th clutch hub: http://www.gmtruckhq.com/drivetrain/...rade-3517.html

Answers to the numbered questions and input is appreciated.

I'd buy a EPC aka PCS, channel plate gaskets and a 4th clutch hub. Since you are an 02, unless it's been rebuilt...it's an automatic on the hub. Have 4 M6 x 1.00 about 70-130mm bolts on hand with the heads missing and edges rounded. These are your "alignment pins/channel P gasket holders" when the trans is on it's side.

Beyond that, it's nothing too crazy. You are going to be half under a suspended drivetrain and it needs to be lowered a decent amount to get the side cover off. Once that's off though, it's relatively simple. Really, it's just the time to do it.

Originally Posted by Twizted 1

I would replace the 4th clutch hub and pump shaft while I'm in there.
The only thing standing in your way is a few bolts. You don't even have to remove the valvebody. Remove the chain cover as an assembly.

Really? If it's removed as an assembly I might as well change the shaft then. I'll add that to the "list".

Originally Posted by DJNight2k

While you are in there I would change at least the TCC PWM sol along with the PC. I'd stick with gm or get a borg warner one. The side cover gasket is a tossup... Sometimes its fine if you reuse it, but it depends on the condition of it when you get it off.. I have one for sale if you do decide to go for it. ($30+shipping/fees) Original GM one. Boost valve would depend if you want to take the valve body off.. Pretty sure the clip that holds it in is on the back side of the vb. (check your instructions) Taking that off you have to worry about the checkballs dropping out and you would need spacer plate gaskets too. Guess it depends on how much you want to spend whether you get all the solenoids or just the PC/TCC. I usually don't do the shift solenoids myself. Hardest thing is getting the side cover out of the way once you get it off.. pry down really hard on the cradle... and it will be able to come out. The rack you need to remove the bolt on the drivers side, and loosen the PS one and pry the rack up so that you don't separate the intermediate steering shaft.. that coming apart is a bad thing. Hope that helps. LMK if you have any other questions.

Yes this helps. So, I'll change the TCC Solenoid as well. So that's that, the PCS, and the 4th gear hub. - Also gaskets for the VB? and possibly the side cover. I have heard as well that sometimes they rip when removed. I don't really want to disassemble the VB if that's what it takes to replace the boost valve. The directions show this http://img7.imageshack.us/img7/9305/38b2.jpg

Originally Posted by BillBoost37

I'd buy a EPC aka PCS, channel plate gaskets and a 4th clutch hub. Since you are an 02, unless it's been rebuilt...it's an automatic on the hub. Have 4 M6 x 1.00 about 70-130mm bolts on hand with the heads missing and edges rounded. These are your "alignment pins/channel P gasket holders" when the trans is on it's side.

Beyond that, it's nothing too crazy. You are going to be half under a suspended drivetrain and it needs to be lowered a decent amount to get the side cover off. Once that's off though, it's relatively simple. Really, it's just the time to do it.

This is an original trans as far as I know. And would you recommend changing the TCC solenoid as well? I've experienced the torque converter unlock shake on other vehicles with the 4t65e but with 200k on it. If it's easy to replace while I'm there I'll do that. I'll make sure I get the channel plate gasket(s)?

And with the bolts.. Is this needed as well? I can't use the bolts that go through the gasket to align it? Or a gasket adhesive spray or something. I'd have to see it to know what you mean

Thanks for the help.

Originally Posted by DJNight2k

If you do go that far, get the metal channel plate gaskets, most aftermarket suppliers can get them. Dave from TEP has them and is amazing to deal with, you can probably get all your parts from him. He ships quickly and I can't say enough of the customer service. I may have a 4th hub here too, I will look around if you are interested.

Okay so there is more than one. I'll look it up on the website.

As a reference:
PCS http://www.amazon.com/ACDelco-104781...vglnk-c2477-20
TCC http://www.amazon.com/gp/product/B00...A2QOROTAURQN0I
Hardened 4th Clutch Shaft: http://www.amazon.com/4T65E-4th-Clut...eywords=84860C
Channel plate gaskets - only found on TEP, 8th item: http://tripleedgeperformance.com/Kit...__Gaskets.html
Side cover Gasket http://shop.advanceautoparts.com/web...rm=side+gasket

Total: $105.26
With side cover gasket: $137.05

Shift Solenoids http://www.ebay.com/itm/4T65E-Transm...55786f&vxp=mtr

Does the part list look good? Complete, correct parts, etc.

Thanks for the help guys.

Originally Posted by Twizted 1

Maybe this will help.
60DegreeV6.com - 4T65E Hardened 4th hub & solenoid upgrade--Pump and Channel Plate Removal

I'm not sure how the diagram is telling me what bolts remove the VB as a complete assembly. Which bolts do and don't come out for that?

Originally Posted by DJNight2k

If i was going to take the channel plate off to do the 4th hub i would take off the valve body and do the boost valve while it was out and on a flat surface. Less chance of having to chase the check balls around. You would need new spacer plate gaskets or a new spacer plate with bonded gaskets on it (that's how they come from gm now). I probably have one of those too if you are interested. But that being said probably not totally necessary to change the boost valve if you don't want to deal with that.

Yeah I don't really want to do the boost valve, it's not completely necessary and would cost me a bit more in gaskets.

Oh wow yes that's really helpful, thanks. Do you recommend changing the shift solenoids too? They're just as easy to get to but it doesn't seem to be as encouraged by some people. Like it's not as important.

Alright. I'd hate to not order them and find out that the resistance is off, then wait a week for shipping. So I may just replace them anyway since they're $15 a piece. How often do they go bad?

I haven't personally seen one bad. (Shift solenoid that is).
If it's not acting up I would leave them alone. You may get a china solenoid that will start acting up when you install it. I would change the problem solenoids and leave the rest alone.
I would however change the manifold solenoid.

Originally Posted by Twizted 1

I haven't personally seen one bad. (Shift solenoid that is).
If it's not acting up I would leave them alone. You may get a china solenoid that will start acting up when you install it. I would change the problem solenoids and leave the rest alone.
I would however change the manifold solenoid.

The shift solenoids claimed to be oem. 4T65E Transmission 1 2 3 4 Shift Solenoid 2 Pieces GM 4T65 | eBay

I can't find a non-aftermarket manifold solenoid on ebay/amazon though.

Right. Non-aftermarket. I'll just stick with the parts: PCS, TCC Solenoid, Hardened 4th gear shaft, and channel plate gaskets. I will order them soon.