Only have 2 and 3
09-26-2018, 07:08 PM
#1
Only have 2 and 3 So my gto has a built 4l65e in it. I sold it and then bought it back a few years later. I got it back with some trans issues.
if I put it in D I take off in 2 and itll auto shift to 3 but that's it. Wont hit 1st or 4th. I can manually command the car to 1st with the shifter and itll go in fine.
we hooked up a tech 2 and watched it. The car is reading its hitting all 4 gears but its obviously only 2 and 3.
Put the car on the lift and used a stethoscope and you can hear solenoids clicking as you command different gears in tech 2. Dropped the pan and it looked good. Checked the shift solenoids and the coils were fine and resistance was fine. Replaced the 1-2 solenoid anyhow. Filled up and back on the ground and still having same issue.
any ideas?
if I put it in D I take off in 2 and itll auto shift to 3 but that's it. Wont hit 1st or 4th. I can manually command the car to 1st with the shifter and itll go in fine.
we hooked up a tech 2 and watched it. The car is reading its hitting all 4 gears but its obviously only 2 and 3.
Put the car on the lift and used a stethoscope and you can hear solenoids clicking as you command different gears in tech 2. Dropped the pan and it looked good. Checked the shift solenoids and the coils were fine and resistance was fine. Replaced the 1-2 solenoid anyhow. Filled up and back on the ground and still having same issue.
any ideas?
09-26-2018, 08:33 PM
#3
The trans worked fine when I sold it prior and I know he didnt beat it hard or open the trans up.
could it be an issue in the valvebody/separator plate/stuck check ball?
could it be an issue in the valvebody/separator plate/stuck check ball?
09-27-2018, 08:15 AM
#4
TECH Junkie
There is an AFL filter in the separator plate. But if it were plugged, it would block fluid from reaching either solenoid.
Did you check the movement of the 1-2 shift valve while you had the solenoid out to replace it? Was it hung up?
Did you check the movement of the 1-2 shift valve while you had the solenoid out to replace it? Was it hung up?
09-27-2018, 08:24 AM
#5
Valve seemed fine, slid back and forth freely and there was no scarring or anything anywhere to suggest it is hanging up. I got the trans kit from Dana @ probuilt autos, plan to give him a clal and see if he has any suggestions on where to look next.
09-27-2018, 08:35 AM
#6
TECH Junkie
He's on this forum quite a bit (or at least used to be...I haven't seen him in a while)
Do a pressure test and let us know what you find.
It's possible that you have an issue with the TCC solenoid, the 3-2 solenoid or the AFL valve (afl valve would be most likely...it does wear and often shows up worse than other valves in a vacuum test). The AFL circuit is shared by all of the solenoids so if you have a huge circuit leak in the AFL circuit caused by wear in the bore, a bad o ring on one of the other solenoids, etc...then the 1-2 shift valve solenoid might be fine but it can't build enough AFL oil pressure to stroke the valve inboard against the spring pressure.
Do a pressure test and let us know what you find.
It's possible that you have an issue with the TCC solenoid, the 3-2 solenoid or the AFL valve (afl valve would be most likely...it does wear and often shows up worse than other valves in a vacuum test). The AFL circuit is shared by all of the solenoids so if you have a huge circuit leak in the AFL circuit caused by wear in the bore, a bad o ring on one of the other solenoids, etc...then the 1-2 shift valve solenoid might be fine but it can't build enough AFL oil pressure to stroke the valve inboard against the spring pressure.
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09-27-2018, 10:07 AM
#8
This sounds above my pay grade to figure out but I can at least copy and paste this about the actuator feed limit (AFL) valve from the Sonnax website
"The AFL valve is a solenoid feed regulator valve that feeds the EPC solenoid and shift solenoids. The OE AFL valve design has a large reaction area and is highly affected by side loading, which wears the valve body bore. The EPC solenoid oscillates the torque signal and AFL oil, which increases valve action. As the bore wear increases, oil pressure is reduced to the shift solenoids, which causes solenoid and ratio codes. The same AFL oil loss results in lower line pressure."
"The AFL valve is a solenoid feed regulator valve that feeds the EPC solenoid and shift solenoids. The OE AFL valve design has a large reaction area and is highly affected by side loading, which wears the valve body bore. The EPC solenoid oscillates the torque signal and AFL oil, which increases valve action. As the bore wear increases, oil pressure is reduced to the shift solenoids, which causes solenoid and ratio codes. The same AFL oil loss results in lower line pressure."
09-27-2018, 10:55 AM
#9
TECH Junkie
The "on/off" action the solenoids gives...only actually strokes the valve due to AFL oil. To get very basic, when a soleonoid is "on" it is blocking the exhast path for the AFL oil. So, pressure builds up between the solenoid and the valve...that pressure acts like a piston and moves the valve. for the 1-2 shift valve, this pressure build up has to be stronger than the spring force on the other end of the valve. If it's not...then the valve won't move.
That's why a worn afl bore is listed by ATSG, Sonnax, GM, etc as causing wrong gear starts, etc.
This is direct from sonnax...the things in red look like exactly what you're experiencing.
I'm not saying 100% this is your problem. But It's certainly a place to start looking.
Symptoms:
If you can't find anything else...you can take your valve body to any reputable local trans shop and they can vacuum test it for you. If they can't vacuum test...I'm not sure how reputable they are I guess. They probably won't charge much.
If the AFL bore vacuum tests bad...they can either ream the bore and install a sonnax fix kit, or you can source a new valve body.
That's why a worn afl bore is listed by ATSG, Sonnax, GM, etc as causing wrong gear starts, etc.
This is direct from sonnax...the things in red look like exactly what you're experiencing.
I'm not saying 100% this is your problem. But It's certainly a place to start looking.
Symptoms:
- Wrong gear starts
- Solenoid performance codes
- Erratic line pressure
- Clutch failure
- Band failure
- No 4th
- Harsh shifts
- 2nd Gear starts
If you can't find anything else...you can take your valve body to any reputable local trans shop and they can vacuum test it for you. If they can't vacuum test...I'm not sure how reputable they are I guess. They probably won't charge much.
If the AFL bore vacuum tests bad...they can either ream the bore and install a sonnax fix kit, or you can source a new valve body.