Is my 4l60e broken? Help!!!
08-28-2012, 07:35 PM
#1
Is my 4l60e broken? Help!!! Car: 2002 Ls1 with LTs & exhaust 60k miles.
Driving home from work today casually.
Starting moving from a stop sign, didn't exactly mash the gas but didn't take off slowly either.
I heard a small pop sound. RPMs went up! and I slowed down.
Car does drive in OD but doesn't go faster than 15mph and rpms go up.
Car has 1,2, and 3 but No reverse.
If I start the car , the rpm drop very little when I put the car in reverse and come back to normal in drive or park.
Slight sound coming from under the car too.
Any help, insight is appreciated.
Thanks!
Driving home from work today casually.
Starting moving from a stop sign, didn't exactly mash the gas but didn't take off slowly either.
I heard a small pop sound. RPMs went up! and I slowed down.
Car does drive in OD but doesn't go faster than 15mph and rpms go up.
Car has 1,2, and 3 but No reverse.
If I start the car , the rpm drop very little when I put the car in reverse and come back to normal in drive or park.
Slight sound coming from under the car too.
Any help, insight is appreciated.
Thanks!
Last edited by bad_408_vert; 08-28-2012 at 08:07 PM.
08-28-2012, 10:56 PM
#4
Moderator
Based on your description and the "wobbly belt sound" my guess is that the trans oil pump has failed and is producing very low line pressure. The reverse circuit has some inherent leakage in it and needs moderate pressure to seal the "Belleville" plate; more pressure than you now have. The pump can be tested by connecting a pressure gauge to the side port; I'd bet that it is very low.
A bit far fetched, if your boost valve popped out, you might have these symptoms as the line pressure would be very low and the reverse line would be open. This could easily be checked by dropping the pan. This hypothesis probably doesn't explain the sound though.
Obviously a local trans shop could check all this in a few minutes. If it is indeed the pump, it will need to be removed and opened up. After 10 years and 60K miles you might want to go with a full rebuild. 2002 is a good year and just a few upgrades would give you good life. I would go with a 4L65E rebuild kit which includes the 7-friction 3/4 clutch, add a Sonnax Smartshell, a Sonnax performance boost valve and a Borg Warner forward sprag.
A bit far fetched, if your boost valve popped out, you might have these symptoms as the line pressure would be very low and the reverse line would be open. This could easily be checked by dropping the pan. This hypothesis probably doesn't explain the sound though.
Obviously a local trans shop could check all this in a few minutes. If it is indeed the pump, it will need to be removed and opened up. After 10 years and 60K miles you might want to go with a full rebuild. 2002 is a good year and just a few upgrades would give you good life. I would go with a 4L65E rebuild kit which includes the 7-friction 3/4 clutch, add a Sonnax Smartshell, a Sonnax performance boost valve and a Borg Warner forward sprag.
08-29-2012, 08:53 AM
#5
Moderator
bad_408_vert PM'ed me to ask if perhaps it is a stripped sunshell based on this tread:
https://ls1tech.com/forums/automatic...oke-4l60e.html
As ArkBird96 pointed out in that thread, a stripped/broken sunshell will generally "only" take away 2nd, 4th and Reverse.
bad_408_vert, you said you have 2nd, but perhaps the trans tried 2nd, the revs went up and the PCM then shifted into 3rd.
On my earlier thread, I should have added that a pump failure generally grinds up a lot of metal and this will require a complete rebuild. Unfortunately any failure that grinds up metal (including a stripped sunshell) should be handled with a complete rebuild with careful cleaning, sending the converter out for cleaning (opening it, cleaning it and welding it back up), replacing the trans cooler and flushing the cooling lines.
So, the bad news is, whether it is the pump or the sunshell, you will be looking at a complete rebuild, converter cleaning, and trans cooler replacements. Yes, some people take short cuts on this, but then often complain three months later that their "new" trans failed.
https://ls1tech.com/forums/automatic...oke-4l60e.html
As ArkBird96 pointed out in that thread, a stripped/broken sunshell will generally "only" take away 2nd, 4th and Reverse.
bad_408_vert, you said you have 2nd, but perhaps the trans tried 2nd, the revs went up and the PCM then shifted into 3rd.
On my earlier thread, I should have added that a pump failure generally grinds up a lot of metal and this will require a complete rebuild. Unfortunately any failure that grinds up metal (including a stripped sunshell) should be handled with a complete rebuild with careful cleaning, sending the converter out for cleaning (opening it, cleaning it and welding it back up), replacing the trans cooler and flushing the cooling lines.
So, the bad news is, whether it is the pump or the sunshell, you will be looking at a complete rebuild, converter cleaning, and trans cooler replacements. Yes, some people take short cuts on this, but then often complain three months later that their "new" trans failed.
