Jump to content

Default 4L65E - Lost All Gears? Acting Like Its In Neutral


Recommended Posts

My suggestion would be to pull a cooler line to verify that you have a broken pump. Usually I would suggest pulling one at your trans cooler and stick it inside of a clear jug. Follow the transmission lines from the trans to your cooler. The bottom line on the trans is the pressure line so this would be the one to use so you know which line to pull at the cooler. If you fire up your vehicle and it does not pump with a pretty strong stream then you have a broken pump. Chances are if you do have a broken pump you will need to have the converter repaired as well. The other possibility is that you have a broken input shaft. This will cause a no movement condition as well. Either way it sounds like you will need to pull your trans and have it repaired. Vince

Link to comment
Share on other sites

I had the same thing happen to me twice and it was the pump, but my fluid level was super high. I was told that most pumps in those transmissions have a 13 vane pump so the walls are thinner and will break easier. I opted for a 10 vane pump when I rebuilt mine and it's been holding so far. Hopefully you didn't snap an input shaft. That'll set you back a bit more. The pump you could actually replace yourself, but like Vince said, you will need to pull the trans.

Link to comment
Share on other sites

I had the same thing happen to me twice and it was the pump, but my fluid level was super high. I was told that most pumps in those transmissions have a 13 vane pump so the walls are thinner and will break easier. I opted for a 10 vane pump when I rebuilt mine and it's been holding so far. Hopefully you didn't snap an input shaft. That'll set you back a bit more. The pump you could actually replace yourself, but like Vince said, you will need to pull the trans.

:withstupid:

 

First thing to check, when looking at the fluid is it *above* the fill line on the dipstick - that means you have a pumping failure/issue. Agreeing with Vince, see if there is fluid being pumped, I found it easier to undo the bottom line at the front of the truck where the cooler is. If the unit isn't pumping, it has to come out. If it *is* pumping, then the problem might be electrical or a failure in the valve body? :dunno: The issue could also be excessive clutch wear dust/debris clogging a fluid passageway in the valvebody, and/or the loss of a shaft seal, etc.

 

Mr. P.

Link to comment
Share on other sites

If it *is* pumping, then the problem might be electrical or a failure in the valve body? :dunno: The issue could also be excessive clutch wear dust/debris clogging a fluid passageway in the valvebody, and/or the loss of a shaft seal, etc.

 

Mr. P.

 

Here's the thing. Forward or reverse really do not require any electronics's so I would highly doubt that would be the case. A plugged filter can be an issue however usually you will get some movement when you first fire up the vehicle until the filter plugs up with what is in the bottom of the pan. None the less if there is enough crap in the pan to plug a filter the unit is on its way out. Vince

Link to comment
Share on other sites

  • 2 years later...

2005 Silverado SS AWD ----- Same sitution saturday on the freeway cruising at about 65 - 75 pulled over and I had absolutely nothing in every gear. Each gear felt just like neutral.

chevy dealer is working on it now. :confused:

 

Did you ever find out what the problem was?

 

Coincidently, I have the same EXACT issue right now with a Friend's Escalade.

 

Lost all forward/reverse movement. He said for about a year, on cold start, the truck takes slightly longer than usual to go into gear initially. And, on cold start there is sometimes a hydraulic 'moan' from under the truck.

 

Last night, he was out driving and upon getting on the the highway from a stop, it started slipping at the top of 1st. Hit the limiter on the 1-2. Said it was like he was spinning the tires before it hit the limiter, but it's AWD so that wasn't the case. After this occoured, pulled over and had no gears at all. I pulled it to the shop, got a line pressure gauge on it and it's barely got 50psi in P/N with EPC commanded to max line psi. WOT in Reverse produces about 20 psi tops, whereas should be upwards of 300+. You can also hear a very loud moan from the pump area, and the more line psi you command, the louder the moan gets. Almost like a power steering system with air, that kind of noise.

 

Teardown shows forward clutches burnt and slight wear on the 3-4's as well. Rest looks pretty normal.

 

However, I can't, for the life of me, find ANYTHING wrong with the pump/filter/valvebody/epc screen. I have no clue why it has no/low line psi! Very frustrating. Pump vanes/rings cover and body all look great.

 

Any help appreciated guys!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...