Common 4L60E Failures

killian96ss · Post by **killian96ss** » Fri Mar 31, 2006 11:06 am

Before guessing at transmission problems, check for fluid level and have the PCM scanned for trouble codes FIRST. This guide is meant for problems that do not show up as PCM codes. Also, many problems that show up as transmission are actually PCM or electrical, and external to the transmission.

Common failures on 4L60E, symptom -> cause -> any possible repair:
1. Slow, slipping or no reverse: “lo-reverse” clutches are worn out, fluid leak in the reverse apply circuit, or broken sunshell. It is possible to remedy a fluid problem by removing the checkball from its cage in the case in the rear of the trans may help (must remove valvebody), or adding a high-viscosity additive such as Lucas Transmission additive or other seal restorer product.
2. No 3rd or 4th gear: “3-4” clutches are worn out. Remove & Replace.
3. Sudden grinding noise with no prior warning primarily in 2nd gear, behavior in reverse may be abnormal; sunshell is fractured. R&R. Try not to run or drive the car or further damage could result.
4. No 2nd or 4th gear. 2-4 band is slipping. Servo seals may be damaged (can be fixed without removing trans. Otherwise, 2-4 band is worn out. R&R.
5. Trans shifts into gear harshly, 3rd gear starts, manual 2nd available but no 1st, no 4th, and no TCC lockup: No power to transmission, or trans is in limp-home mode. Check trans fuse underhood, and make sure transmission electrical connector is plugged in. Easy fix.
6. No 1st or 4th available: shift A solenoid failed. Easy fix in the pan.
7. No 2nd or 3rd available: shift B solenoid failed: Easy fix in the pan.
8. No TCC lockup: Brake pedal switches improperly adjusted (always on), TCC solenoid failed (easy fix in the pan), TCC clutch worn out (must remove trans and replace TC).
9. TCC always locked: TCC apply solenoid circuit shorted to ground, TCC solenoid blockage (easy fix in pan), or TC broken (must remove trans and replace TC).
10. 1-2 Shift shudder at WOT; delayed or abnormal 1-2 shift: 1-2 accumulator piston cracked or stuck cocked in the bore. Easy fix in the pan.
11. Horrible noise in 4th and feels like the brakes are on: overrun clutches are applying due to a cracked or leaking forward piston. Overrun clutches will be worn out after 30 seconds of this behavior. Car can be safely driven in D. R&R.
12. Soft shifting, gradual performance degradation: Leaking boost valve; clogged EPC filter screen, leaky seals. Transgo HD2-C kit fixes first two without removing trans. Seal restorer may fix last problem, but probably R&R.
13. No forward movement in OD or D, but L2, L1 and R work: Forward sprag is broken. R&R. Try not to run or drive the car or further damage could result.
14. Extremely harsh shifts from P or N, normal shifts at WOT: EPC (Electronic Pressure Control) solenoid failed. Easy fix in pan.
15. Loud bang, grinding sound, loss of all gears, and a binding driveshaft: snapped output shaft. R&R.
16. Trans seems noisy when moving in 1st and Reverse, noise goes away instantly if you shift to N: Reaction planetary is worn out due to high miles or insufficient lubrication. Not a critical failure, but not a good sign either. R&R.
17. No movement in any gear: pump failure, or total loss of fluid. R&R, or refill pan and find the leak. If out of fluid, avoid running the engine until the trans is refilled to avoid pump damage. To check for pump failure, check fluid level with the engine off, then start the engine and recheck fluid level. If level does not go down when engine is running, the pump is broken.
18. Trans does not upshift out of first, speedometer reads zero at all times: VSS failure. Easy fix on rear of transmission.
19. Transmission does not shift automatically, only manually. Swap in a known-good PCM, check wiring, check other sensors.
20. 1-2 shift is delayed and harsh, may not shift into OD: Check TPS for smooth and linear electrical response over the entire range of motion. If not, replace.

Credit for this information goes to Sherlock9C1 from the Impala SS forum.

This info can be useful and maybe it should be stickied?

Steve

Post by **HenryJ** » Fri Mar 31, 2006 11:23 am

Wrong , wrong, just not right...where do I start?

j/k

Just seems that way with us lately sometimes

I'l put together a stock information page. Thanks!

killian96ss · Post by **killian96ss** » Fri Mar 31, 2006 11:35 am

HenryJ wrote:Wrong , wrong, just not right...where do I start? j/k

Just seems that way with us lately sometimes

We are both stubborn and hard headed!

My wife is the same way, which makes me wonder how we have managed to stay happy for the past 9 years.

Steve

Post by **HenryJ** » Fri Mar 31, 2006 11:59 am

killian96ss wrote:... stubborn and hard headed! ...

I still have hope for you!

Here's the page - 4L60E Tramsmission Failure List

quickbiker · Post by **quickbiker** » Sat Apr 01, 2006 4:56 pm

I never knew that ever had problems. Best tranny I ever had so far.

Post by **Walt** » Sat Apr 01, 2006 7:20 pm

killian96ss wrote:
HenryJ wrote:Wrong , wrong, just not right...where do I start? j/k

Just seems that way with us lately sometimes
We are both stubborn and hard headed! My wife is the same way, which makes me wonder how we have managed to stay happy for the past 9 years.

Steve

I kinda fit that description as well, but you know what the difference between me and you two is? You two are a whole lot smarter than me

That's why I don't ever argue/debate

Post by **HenryJ** » Sat Apr 01, 2006 7:27 pm

wamason wrote:...You two are a whole lot smarter than me...

BOY! We have you fooled

GeorgesBlazah · Post by **GeorgesBlazah** » Sat Apr 01, 2006 10:15 pm

what about it not wanting to go into overdrive on the highway? i was running up and down some steep hills and doing alot of city driving ~2 hour drive and when i got on hwy it took forever to get into OD. i figured the tranny was runnin hot. btw i have no external cooler...its on the list however.

Blaze One · Post by **Blaze One** » Sun Apr 02, 2006 12:22 am

George , maybe since you regeared the computer is not calculating proper rpm's/speed . You may need to invest in a powerprogramer if you have not already , and the reprogram your shift points .

Snoman002 · Post by **Snoman002** » Sun Apr 02, 2006 5:55 am

How 'bout the harsh 1-2 shift and bucking between 40 and 55.

Torque converter lockup apply piston problem.

Commonly seen with a P1870, but not always.

killian96ss · Post by **killian96ss** » Sun Apr 02, 2006 9:37 am

The list above shows the common failures for the 4L60E along with the symtoms and the appropriate fixes. If anyone knows of other problems and the correct fix I'm sure HJ can add them to the list, however if you only know the problem or symptom and not how to correct or fix the problem then it can't be added because it won't really help anyone.

Steve

Snoman002 · Post by **Snoman002** » Sun Apr 02, 2006 4:12 pm

killian96ss wrote:The list above shows the common failures for the 4L60E along with the symtoms and the appropriate fixes. If anyone knows of other problems and the correct fix I'm sure HJ can add them to the list, however if you only know the problem or symptom and not how to correct or fix the problem then it can't be added because it won't really help anyone.

Steve

Driving problem: Harsh 1-2 shift and possible harsh 2-3 shift. Usually expereinced after driving for a while. Some also notice a "bucking" between 40 and 55 MPH, lightly touching the brake pedal (just enough to turn on brake lights) causes the bucking to go away. Usually results in the CEL illuminating and a P1870 code being set, this is not always the case though as the problem must happen on two CONSECUTIVE key cycles for the CEL to set.

Problem: Torque converter lockup apply piston has worn in it's bore and is lodging.

Diagnostic: Take it to the dealer. They can monitor torque converter lockup % and tranny input and output speed.

Repair: 1,Replace valve body (~$900 at dealer). 2, Use a sonnex reamer to open up the bore and then sleve it and put in a new piston (~$150 for parts minus what ever you get for the reamer when you sell it on ebay, or just buy the reamer there and save some and then resell it).

This only affected a few years of 4L60's and the issue was solved on trannys with a build date of ~Nov 1999 (not exactly sure on that date anymore).

killian96ss · Post by **killian96ss** » Sun Apr 02, 2006 4:47 pm

Snoman002, is this problem only for 4L60E's made before 1999?

Steve

Snoman002 · Post by **Snoman002** » Sun Apr 02, 2006 6:20 pm

killian96ss wrote:Snoman002, is this problem only for 4L60E's made before 1999?

Steve

Yes, from my understanding it only is a problem in transmissions with a build date of near the end of 99. Unfortunately you never know if the build date of the tranny is anywhere near the build date of the truck.

I beleive that it is only an issue with trannys build between 97 and 99, not exactly sure on that though. At a certain year they changed the way the torque converter lockup worked and they started having some problems. Basically they started to "slip the clutch" in the torque converter instead of having it just engage. unfortunately they had some issues with the piston that controlls the fluid pressure to the torque converter clutch and it would wear in it's bore. This made the piston not travel smoothly in the bore and it made varing the amount of lockup a guessing game, this causes the computer to try and compensate and you end up with the bucking. OR, the piston lodges more completely and the computer senses slipage, to compensate it boosts line pressure and that causes the harsh 1-2 and 2-3 shift. Eventually it will happen enough to set a code, unfortunately your torque converter clutch will probably be toast at that time and you will then need to replace the whole converter.

If anybody is interested search for "EC3, or ECCC, lockup 4L60e".