47 Indian

Being a newbie I think I've read nearly every post regarding the problem where the 4L60e trans will not shift into third or forth.

The trans was rebuilt and has less than 300 miles on it and operated perfectly until I hit the throttle at a very low speed, down shifting into first then second and no further. The trans will only shift from first to second from a dead stop. Once hitting RPMS to into third it revs up with no engaging of third.

I had a neighbor run the OBD2 against his Snap-on computer which indicated the trans was shifting into third then dropping back to second, however you could not feel the trans shift. Unfortunately he is not a transmission guy.

Pulling the main lead to the trans does not force the the trans to default to third gear as some have suggested. It stays in first and does not shift into second. Reconnecting the lead give me first and second again.

Given this, staying is first in the disconnected mode, indicative of a bigger problem? I should note the installer, not the builder was @ two quarts low of fluid which I was unaware of until this problem surfaced which I corrected.

I'm not knowledgeable on transmissions and will require someone to trouble shoot the problem in detail. Just trying to eliminate or identify specifics to streamline the process.

Suggestions/thoughts appreciated.

bbond105

Sounds like the 3-4 clutches are gone. Do you have a warranty?

47 Indian

That's what I'm afraid of. As for warranty this was a side job by a guy who wrenches transmissions as part of his work for a local government agency. Known him for a while. Has a good reputation, unfortunately he is currently recovering from a accident and.
Unknown recovery time.

Trying to avoid the big buck repair shop.

mrvedit

Your statement that the trans stays in 1st gear when then the electrical connector is disconnected suggests that Solenoid B (also called 2-3) is stuck in the ON position. Either that or a problem in the Valve body. I would start by replacing both solenoids; both because they are only $12 a piece and people sometime mix them up when they get disoriented under the car; also if one is bad the other is probably old too.
There is a good chance your solenoid B is stuck and won't "rattle" when you shake it.

47 Indian

Thanks, I'll get on that in the next day or two......

47 Indian

Okay, pulled the pan in preparation to replace both A and B solenoids to find dark smelly fluid coupled with silver flakes. To that end the 3rd and 4th gear clutch pack is fried and most likely the 1st and 2nd have damage.

If the transmission was properly rebuilt as I believe it was are their any thoughts as to why the clutches would fail after @300 miles? Could it be in the tuning shift points?

Any and all thoughts appreciated as I don't want to go down this road again.

mrvedit

Low line pressure will cause very premature wear. A few possible reasons:
1. Bad Pressure Control Solenoid.
2. Bad tune
3. Engine sensors (TPS, MAF) not indicating high engine load which should increase line pressure.

I would suggest purchasing a trans pressure gauge (search ATD-5550 on Amazon - $34) and connect it to your trans before removing/repairing it. This will help diagnose where the problem might be. Typical pressure:
Park - idle: 60-75psi
Reverse - idle: 150+ psi
Drive - idle: 60-75 psi
Drive - blip the throttle: 175+ psi

The pressure gauge has a long hose so that you can watch pressure while driving, especially during the shifts.

47 Indian

Got that. I'll order the gauge this evening, put the pan back on and add a couple quarts of ATF to test.

Given I only have 1st and 2nd gear will that be sufficient to get a accurate reading in the drive idle and blip mode?

Any ideas what to look for in the tune that would cause/contribute to the failure?

Thanks.

GMCSIERRA5.3

silver flakes or silver glitter usually comes from the converter

mrvedit

Sounds rights. Perhaps a worn out converter clutch is causing the thick smelly fluid.

Still strange that the trans starts/stays in 1st gear after pulling the connector. Did the solenoid replacement change anything?

47 Indian

What I've done to this point is place the pressure gauge on the trans after putting the pan back on with a few quarts of fluid. I was able to obtain the following readings; Park at idle was 55#'s, Reverse 75#'s, Drive at idle 55#'s and "blipping" the throttle in drive was 175+#'s.

I did not want to change the solenoids as of yet. I'm wanting to check the PCM tune to see what those readings/settings might suggest for the low pressures indicated above. If they are set at the appropriate level and I'm only getting the above pressure readings then I'm pretty confident the solenoids are shot.

I priced the solenoids locally. Folks here are pretty proud of their parts, nearly double whats been indicated here on line. Amazon here I come, again.

As for the flakes, they are shiny and very glitter like. I'll try to get a picture to post. As for the ATF, it appears more brown at this point. The pan bottom had a fine black layer of material.

All and any thoughts on the pressures readings and other onditions/concerns appreciated.

Thanks.

bbond105

I don’t think the solenoids are going to do you any good. Solenoids don’t turn your fluid metallic and brown.

47 Indian

That's why I didn't go ahead and replace the solenoids just yet. I'll wait until I run it for tune. If the tuning points are off that may be just one problem given the post regarding the convertor and or clutch. I will try to run a ohm test and shake test on the solenoids to determine their viability.

Hopefully tomorrow we bring more information forward.

GMCSIERRA5.3

all that glitter in the pan can clog up the solenoids and cause them not too function properly

bbond105

The point that everyone seems to be missing is that all that glitter had to come from somewhere and most likely whatever is making the glitter is why the trans want shift.

47 Indian

Going to check the pcm trans tuning tomorrow. Hopefully I'll garner some insight if the settings may have contributed to the failure. Regardless it's gotta come out of the car for final determination.

GMCSIERRA5.3

all the 4l60s ive seen with the glittery stuff have always been from the converter..oem converters that is

Circle-D_Brian

If this was converter related it would affect all gears and not just 3/4. I'm guessing metal on metal clutches and steels.

-Brian

47 Indian

An attempt was made to determine the PCM tune however, due to antiquated equipment we didn't garner much. What we did find that on initial start up both solenoids one and two and two and three were on.

Shifting from first to second was normal. When the trans shifted into second, solenoid one and two went off. Solenoids two and three came on for an instant then back to off. The trans went into downshift mode with total loss of engagement of gearing. This did not seem like slippage but more like going into neutral. Solenoid one and two came back on after slowing the vehicle down to 20 from 40 at which time first gear engaged.

One other test revealed that Trans Adapt Function cells 5, 6, 7, 8, and 9 of the fourteen cells were the only one's registering any readings. Thoughts?

I've attached a picture depicts the material found in the fluid. It may appear as small white flecks in the picture. Trust me it's silver colored with a fair amount stuck to the pan magnet.

Given the circumstance the trans is coming out. Any thoughts on any other diagnostics to conduct before pulling out?

Can a PCM be benched tested out of the vehicle for tune?

Thanks again for your comments.

mrvedit

No idea what you are saying, there are not 3 solenoids.
There are two shift solenoids - Solenoid A and Solenoid B.
There is also a 3-2 downshift solenoid.
Please edit your post to describe what Solenoids A and B are doing.

Thanks.