4T65e Hard shift into reverse

[GerGa]

Hey,
I have a 2004 Buick Lesabre with 4T65e transmission and when hot, it sometimes shifts a little hard into reverse. It grabs and the rpm's go down. One time I actually stalled the car shifting from drive to reverse, but I was rolling forward slightly on a slight hill. I'm not one of those guys who shifts into gear all the time while rolling the wrong way though, I was in a rush to pull a U-turn. First time I stalled an Automatic lol.

Bought car not too long ago at 47k, now at 53k. Fluid was low when received and replaced 55% of the fluid with Maxlife ATF(pan drop), and new filter. Plan to change fluid again and install Transgo shift kit(only shifts 2, 3 because 4 is in the side pan, which requires a tranny drop on this car).
Hard shift into reverse not much to worry about or no? Should I run some kind of treatment before new fluid like Lubeguard Red?

Thanks

 

[Greasymechtech]

Replace the PCS...

 

[901Memphis]

Good call on the transgo kit, that should help the clutches and steels last longer in the 2/3 shifts.

See if you can get a transmission shop to pull the codes for free it's probably pressure related, but a 2004 model should have the better PCS and shift solenoids they started using in 2003+, still probably PCS related.


Triple edge 4T65e common problems

 

[901Memphis]

Also I will add that lubegard is not necessary when using Maxlife, it's already an advanced synthetic fluid an it won't really help much.

Lubegard has most benefits when added to a mineral DexronIII type fluid.

Good call on the Maxlife too, I use it exclusively on my triple edge 4T65e in my Century.

 

[GerGa]

Originally Posted By: 901Memphis
Good call on the transgo kit, that should help the clutches and steels last longer in the 2/3 shifts.

See if you can get a transmission shop to pull the codes for free it's probably pressure related, but a 2004 model should have the better PCS and shift solenoids they started using in 2003+, still probably PCS related.


Triple edge 4T65e common problems



I have an ELM 327 OBDII bluetooth adapter and Torque Pro diagnostic app for my android phone, and it doesn't show any codes. In fact I have not seen a check engine light on this car. Is it a code that only shows up when it happens, then goes away? Does it throw the code behind the scenes without giving the CEL?

Have you replaced your PCS or your transmission yourself? I see you bought one from triple edge. I am interested in doing the PCS. Not a mechanic, but like turning wrenches and do all general maintenance on my car. Did the intake manifold gaskets and it went well(first time doing gaskets on a car).
I take it doing the PCS requires lowering the transmission somehow, do you unmate it from teh engine, or lower both down? OR am I a bit off base.

I figure while I do a PCS, I could do the 4th gear shift kit as well.

Thanks

 

[901Memphis]

I have the same adapter, it won't show transmission or body codes, just ECU codes.

If it has a hard shift code it will need a specialized scanner tool to see it.

Here is a video of the PCS replacement, not sure of the quality though and this is only part one they don't do much here. The PCS should be in the side cover. Also after replacing the PCS you want that specialized scan tool to reset the adaptive learning to get the best results.

https://www.youtube.com/watch?v=oTVpIod6Eas

No i didn't replace my PCS, i had triple edge build me a standard rebuild with all the goodies already in it and had a local mechanic install it for me.

 

[GerGa]

I often get right on the highway when the car is cold, and I notice it doesn't shift into 4th until the transmission is hot (after a few miles). Once warm, there is no issue. I assume that is normal behavior, does anyone agree, or is there something wrong?

 

[Trav]

Before tearing into it do a line pressure test, its easy on these units. Don.t worry about the 4th gear input shaft a 2004 already has the hardened one.

Pm me your email, i will sent you the full rebuild book in PDF form.

 

[Clevy]

Has the linkage been looked at?

 

[GerGa]

Originally Posted By: Trav
Before tearing into it do a line pressure test, its easy on these units. Don.t worry about the 4th gear input shaft a 2004 already has the hardened one.

Pm me your email, i will sent you the full rebuild book in PDF form.



It also shifts really slow sometimes, that's why I want to put in the shift kit. I also notice that it bangs into gear when I have gone from no throttle to mashing the gas pedal. Is it just expected that my line pressure is low, therefore need a PCS?

 

[Trav]

We will have some real info with pressure numbers. It could be a few things like a internal seal that are known to leak and replaced with a longer lipped one.
Lets not guess to much, it just causes needless worry sometimes, proper diagnosis is everything. LOL

 

[GerGa]

Originally Posted By: Trav
We will have some real info with pressure numbers. It could be a few things like a internal seal that are known to leak and replaced with a longer lipped one.
Lets not guess to much, it just causes needless worry sometimes, proper diagnosis is everything. LOL


You are very right about messing around with needless worry

 

[GerGa]

I just checked the pressure quickly. In the manual, gears P R N have a minimum of 79-101 psi, I am getting basically that, P I am getting slightly low at around 75 to 79 at times.
D1 has a minimum of 146-187 psi and I was showing around 120 to 125 psi, so thats low.
By the way this is all sitting in place with the brake on, no gas applied.

Drove a bit too and pressures didn't go over max, but I don't know if testing for max would actually be successful without a Tech II scan tool controlling the PCS instead of just driving around(I think that's how they do it??).

 

[Trav]

Generally anything wrong in the PCS will set a P0748 and command max line pressure, it could have a bad seal or it could be dirty.
Changing it is more of a PITA than difficult and can be done in the car as can all the clutches, drums, seals and valve body.

A dirty filter or leaking filter seal can cause this slight loss of pressure, it does use a real filter and not just a rock catcher.
If it were mine i would do whatever i could from underneath first, the filter, seal and accumulator kit. Use 2 12oz bottles of lubeguard red, even with synthetic fluids.
The esters do a good job of long term cleaning and helps with seals pliability which may be of some benefit to this unit as it uses the OE short lip seals.

Run Amsoil ATF not the Dex VI low viscosity but the normal one, the slightly higher viscosity may help with pressure slightly. Keeping the unit temp to about 180 is optimal for these and helps with seal life, a cooler from the Police models work well and is easy to install.
It is a real bolt in cooler not a through the radiator with clips job. Use a thermostat with it. PM if want part numbers.
If that doesn't do the trick go in after the PCS.

When you do the accumulator make sure and use a line clamp from Sonax part# 84532-01K and make sure the lines seated and the differential tube is connected up top.
Thats about all you do without getting getting really into the weeds with this.


http://www.sonnax.com/parts/2534

http://www.oregonperformancetransmission...e=SNX-84532-01K

 

[GerGa]

I am going to try to find a transmission shop to read the codes.
I changed the filter and seal when I did a maxlife atf drain & fill so I don't think the seal should be leaking. I did use the cheaper AcDelco filter so I may end up changing over to a better quality Allomatic filter for $15 for good measure..
I think I will listen to you about the Amsoil Dex III viscosity fluid and lubeguard. I already have 3 gallons of Maxlife but given the fact that some have issues when switching over from dex III to thinner Dex VI, it should be a good idea. And Maxlife may have made the tranny act up a little more, although I can't be certain(I did not drive the car enough to become accustom to it's typical behavior before the Maxlife drain and fill).
I have the Transgo shift kit and Sonnax line retainer ready to go.
I also plan to install a cooler, very interested in coolers with thermostats. My fluid temps have not broke 165 but it was only 55F outside on the warmest day that I checked fluid temp and it will get hot out so I probably will need it.

PS is Amsoil available anywhere cheaper than direct from Amsoil because it goes for around 35-36 dollars a gallon direct from Amsoil.

 

[Trav]

PM Pablo he will hook you up with some. Get one x 2.5 gal jug and 1x 1 gal that gives you 14 qts which is perfect for a line off exchange with a couple of qts to spare (easy on this unit).

 

[GerGa]

So I did the in pan filter, shift kit, and magnefine in line filter, used Amsoil Signature multi vehicle ATF, and line off exchamge. Replaced about 9.5 quarts. Used 2 bottles of Lubeguard red. Pulled battery over night.
Shifts much quicker but shifting into 3rd might be a bit slow still, and 4th of course is still slow because the 4th accumulator is in the side pan.

This morning I pulled up to a parking lot and had to back up a bit to key in and it stalled installantly. When I parked I tested shifting to neutral and it might have caught a bit there and not so much to reverse so who knows if actually shifting to reverse is an issue? Trans temp was 180.
Maybe it's just my pcs or would the tcc solenoid have something to do with it too?
I did not get my trans codes scanned before doing the work but maybe I will now after driving a bit.