4L60E second gear issue - Need some advice
04-21-2015, 04:25 PM
#1
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4L60E second gear issue - Need some advice Little background information... a few years ago I burned up second gear, forced a check ball into the separator plate. I have since had that repaired, but the trans still has never seemed right. I don't drive the car as much as I would like to, so I've pretty much just dealt with it up until now.
Car is cam only with a 4k stall -
Going WOT, the trans wouldn't shift out of second gear; it would just bounce the limiter until you lifted. If you got back in it too fast, it would jump back on the rev limiter. Otherwise, after i pedaled it, it would shift into third. Thought it was a tune problem, but I have checked the shift point and rev limiter, there is plenty of rpm left for it to make the shift..
Now, the trans wont shift into second regularly. I have to be over 3k RPM, completely let out, then it'll limp into second, and then it will shift normally from there (WOT in 2nd problem still exists). WOT in first bounces the limiter now, too. I can run out first gear gradually until about 4800 RPM, then it will make the shift, without first letting out.
Pulled the valve body apart and everything appears to be fine. Fluid was clean as well.
Where should i begin to look? Any ideas on what it could be?
Sorry about the long winded post!
Car is cam only with a 4k stall -
Going WOT, the trans wouldn't shift out of second gear; it would just bounce the limiter until you lifted. If you got back in it too fast, it would jump back on the rev limiter. Otherwise, after i pedaled it, it would shift into third. Thought it was a tune problem, but I have checked the shift point and rev limiter, there is plenty of rpm left for it to make the shift..
Now, the trans wont shift into second regularly. I have to be over 3k RPM, completely let out, then it'll limp into second, and then it will shift normally from there (WOT in 2nd problem still exists). WOT in first bounces the limiter now, too. I can run out first gear gradually until about 4800 RPM, then it will make the shift, without first letting out.
Pulled the valve body apart and everything appears to be fine. Fluid was clean as well.
Where should i begin to look? Any ideas on what it could be?
Sorry about the long winded post!
04-21-2015, 05:19 PM
#2
Moderator
The first step in diagnosing non-obvious transmission problems is connecting a pressure gauge to it. Look up "ATD 5550" on Amazon; it is $33 with Prime shipping.
Reporting the pressure, at idle in Park, Reverse and Drive, and the pressure while blipping the throttle is often enough to diagnose problems.
The gauge includes a 6ft hose so that you hang it from your outside mirror while driving and monitoring the pressure at different throttle positions.
In the mean time, check the servo end play by pressing on the servo cover with a crow bar and holding a small ruler nearby to estimate how much it moves.
Problems with the 2-3 shift are nearly always a worn out 3/4 clutch.
Problems in 2nd gear are often excessive servo end play caused by a worn band.
Your description doesn't exactly match the usual symptoms, hence first checking with a pressure gauge. Obviously a trans shop can do this for you too.
Reporting the pressure, at idle in Park, Reverse and Drive, and the pressure while blipping the throttle is often enough to diagnose problems.
The gauge includes a 6ft hose so that you hang it from your outside mirror while driving and monitoring the pressure at different throttle positions.
In the mean time, check the servo end play by pressing on the servo cover with a crow bar and holding a small ruler nearby to estimate how much it moves.
Problems with the 2-3 shift are nearly always a worn out 3/4 clutch.
Problems in 2nd gear are often excessive servo end play caused by a worn band.
Your description doesn't exactly match the usual symptoms, hence first checking with a pressure gauge. Obviously a trans shop can do this for you too.
04-21-2015, 09:57 PM
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Thank you, mrvedit! This is exactly the type of response i was hoping for.
I checked the end play of the servo, and from what I've read, the band is definitely worn. I did not have a small ruler handy, but from what I see, it moves about 3/8 to 1/2 of an inch.
I have the pressure gauge on order, so I should have it by Friday. I'll report back with the pressure readings.
I checked the end play of the servo, and from what I've read, the band is definitely worn. I did not have a small ruler handy, but from what I see, it moves about 3/8 to 1/2 of an inch.
I have the pressure gauge on order, so I should have it by Friday. I'll report back with the pressure readings.
04-21-2015, 10:08 PM
#4
Moderator
The spec on the servo end play is .075 to .125 (or about 1/16" to 1/8"). By 1/4" the band is likely to be slipping. Others here have gotten more life out of their trans by lengthening the servo pin:
Lengthened Servo Pin:
https://ls1tech.com/forums/automatic...t-trouble.html
https://ls1tech.com/forums/automatic...-gear-all.html
https://ls1tech.com/forums/automatic...ckup-help.html
Feedback that it worked:
https://ls1tech.com/forums/automatic...cond-only.html
https://ls1tech.com/forums/automatic...e-2-fixed.html
https://ls1tech.com/forums/automatic...-4th-gear.html
You will still find the pressure gauge useful. It can be used for engine oil pressure too.
Lengthened Servo Pin:
https://ls1tech.com/forums/automatic...t-trouble.html
https://ls1tech.com/forums/automatic...-gear-all.html
https://ls1tech.com/forums/automatic...ckup-help.html
Feedback that it worked:
https://ls1tech.com/forums/automatic...cond-only.html
https://ls1tech.com/forums/automatic...e-2-fixed.html
https://ls1tech.com/forums/automatic...-4th-gear.html
You will still find the pressure gauge useful. It can be used for engine oil pressure too.
05-07-2015, 09:01 AM
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I'm going to bump this. Lol I was working on deadonws6's car with him. When we pulled down the second acumilater we noticed there was no springs in it, there was a tall spacer, and the piston was upside down. The fourth gear acumilater also had no spring in it and just a spacer. This didn't seem right to us. So we put a transgo hd-2 kit in it. We havnt put fluid back in the car and tested it though.
So my question is, will the acumilater's work fine with no springs or should it have springs?
So my question is, will the acumilater's work fine with no springs or should it have springs?
05-07-2015, 10:46 AM
#6
Moderator
What you found was the B&M Shift kit which should never be used as it puts undue strain on the trans and drivetrain. Think of the accumulators as shock absorbers and imagine how long the suspension would last if you replaced the shock absorbers with a solid spacer.
So yes, just assemble it with the Transgo springs and position the piston as instructed. Use at most one spacer in the 1-2 accumulator. If the accumulator pistons are plastic, I highly suggest replacing them with OEM aluminum ones.
So yes, just assemble it with the Transgo springs and position the piston as instructed. Use at most one spacer in the 1-2 accumulator. If the accumulator pistons are plastic, I highly suggest replacing them with OEM aluminum ones.
