4L65E, Low line pressure in all ranges, loss of movement, help!
12-28-2012, 11:58 PM
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4L65E, Low line pressure in all ranges, loss of movement, help!
Well i've got one that has me officially stumped!
I'm working on a friend's '04 Escalade, typical Q9/65E setup. All stock.
Last night, it lost all forward/reverse gears totally. No warning whatsoever. He was accelerating from a stop to highway speeds, and at the top of 1st it started slipping and then nothing. Pulled over, no forward/reverse at all no matter the gear selector range.
Pulled it to the shop, checked fluid, reading is at proper level on dipstick, fluid has slight burnt odor. Performed Line Pressure check, low in all ranges. I can barely get 60psi with the EPC pressure set to max via scantool, even raising the RPM will not produce any change over 60 at most. WOT in Reverse is 15 psi, spec is 300+. You can also hear a very loud moan from the front pump area of the trans. He said it's been doing that for about a year now and seems to be worse on 1st startup when cold. Also, for a while prior to it losing everything, it's been taking longer and longer to engauge into gear 1st thing in the morning.
So, we tore the unit out, benched mounted it and proceeded with a diagnostic teardown. The Forward's are burnt but not horrible, and the 3-4 pack has a little wear but nothing major. However, I cannot for the life of me find ANY issue with the pump! Rotor/vanes/rings/body/cover all look perfect. Filter looks ok and little to no debris/clutch in the pan. Valvebody is very clean as well.
I have no clue why it won't carry proper line pressure, needing some experience with this failure type.
By the sound of it, it almost seemed as if the pump had failed or was sucking air. I was certain we would find a pump problem, but everything looks perfect.
I work as a dealership technicain by day under the Blue Oval, and transmissions are nothing new to me. But i'm stumped on this one!
Help?
I'm working on a friend's '04 Escalade, typical Q9/65E setup. All stock.
Last night, it lost all forward/reverse gears totally. No warning whatsoever. He was accelerating from a stop to highway speeds, and at the top of 1st it started slipping and then nothing. Pulled over, no forward/reverse at all no matter the gear selector range.
Pulled it to the shop, checked fluid, reading is at proper level on dipstick, fluid has slight burnt odor. Performed Line Pressure check, low in all ranges. I can barely get 60psi with the EPC pressure set to max via scantool, even raising the RPM will not produce any change over 60 at most. WOT in Reverse is 15 psi, spec is 300+. You can also hear a very loud moan from the front pump area of the trans. He said it's been doing that for about a year now and seems to be worse on 1st startup when cold. Also, for a while prior to it losing everything, it's been taking longer and longer to engauge into gear 1st thing in the morning.
So, we tore the unit out, benched mounted it and proceeded with a diagnostic teardown. The Forward's are burnt but not horrible, and the 3-4 pack has a little wear but nothing major. However, I cannot for the life of me find ANY issue with the pump! Rotor/vanes/rings/body/cover all look perfect. Filter looks ok and little to no debris/clutch in the pan. Valvebody is very clean as well.
I have no clue why it won't carry proper line pressure, needing some experience with this failure type.
By the sound of it, it almost seemed as if the pump had failed or was sucking air. I was certain we would find a pump problem, but everything looks perfect.
I work as a dealership technicain by day under the Blue Oval, and transmissions are nothing new to me. But i'm stumped on this one!
Help?
12-29-2012, 10:00 AM
#2
This is just a theory. I just built a TBSS unit for a customer at the shop I work in. Vehicle drove in slipping like crazy and the pump making all kinds of noise. Tore the unit down just as you did and saw similar damage. Took the pump apart and it seemed ok and really did not see the noise. Did the normal air checks to the unit before completely tearing the units down and putting the hard parts in the solvent tank I use.
Went to clean off my bench still scratching my head. Did like most would do and squeegee the oil off the bench in to my drain. When all the sudden I pick up the filter to drain some oil out of it and throw it away. I think to myself man this filter seems kind of heavy like its still pretty full of oil. I go to drain it and next to no oil came out of the filter. This is when it hit me for the noise and slipping issue. The element inside the filter had actually collapsed and started to suck itself into the pump pickup part of the filter. I did bust it open as well to inspect the filter. It had minimal debris in it and that is when I saw the element coming apart and clogging the pickup.
Pretty sure the issue was a cheap *** filter was used when the unit had been serviced and this was the end result. A rebuilt unit! Always use a good quality OEM filter either from the dealer, a filter tech or an SPX filtran filter. Never get one from just the local part stores. If you dont know what they are selling you chances are its the cheapest ones they can buy to resell!
Please update the thread. Vince
Went to clean off my bench still scratching my head. Did like most would do and squeegee the oil off the bench in to my drain. When all the sudden I pick up the filter to drain some oil out of it and throw it away. I think to myself man this filter seems kind of heavy like its still pretty full of oil. I go to drain it and next to no oil came out of the filter. This is when it hit me for the noise and slipping issue. The element inside the filter had actually collapsed and started to suck itself into the pump pickup part of the filter. I did bust it open as well to inspect the filter. It had minimal debris in it and that is when I saw the element coming apart and clogging the pickup.
Pretty sure the issue was a cheap *** filter was used when the unit had been serviced and this was the end result. A rebuilt unit! Always use a good quality OEM filter either from the dealer, a filter tech or an SPX filtran filter. Never get one from just the local part stores. If you dont know what they are selling you chances are its the cheapest ones they can buy to resell!
Please update the thread. Vince
12-29-2012, 10:26 AM
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Thank you for taking time from your day to reply Vince, I owe you a few times to say the least from your advice.
I had a huge sense of eleation as I read that reply. During teardown, when I removed the filter, I thought it odd that it felt so heavy as well. I laid it upside down in the drain pan, and drippings began to pool onto the inlet area of the filter. This continued until the inlet was filled up to the top of the filter. After sitting overnight, the fluid still had not passed through the filter, even with me orienting the filter in my hand. I then turned it over, and drained it to look at what element was visible in the inlet opening, and it appears as if it's slightly pulled into the filter housing rather than relaxed.
Digging further, the owner changed the filter/fluid with a parts store kit/fluid 20k miles ago.
The filter will be surgically cut open today, and pictures posted if I find an issue.
It's the ONLY thing that makes sense to me, I mean if the pressure relief ball/spring and pump filter are in place, the pump is mechanically functional, and the filter isn't restricted, there really isn't much that can cause complete loss of line pressure is there? And the pump noise just adds to the supect of that filter.
Thanks bud, and this thread will live to completion and functionality of the unit in full.
I had a huge sense of eleation as I read that reply. During teardown, when I removed the filter, I thought it odd that it felt so heavy as well. I laid it upside down in the drain pan, and drippings began to pool onto the inlet area of the filter. This continued until the inlet was filled up to the top of the filter. After sitting overnight, the fluid still had not passed through the filter, even with me orienting the filter in my hand. I then turned it over, and drained it to look at what element was visible in the inlet opening, and it appears as if it's slightly pulled into the filter housing rather than relaxed.
Digging further, the owner changed the filter/fluid with a parts store kit/fluid 20k miles ago.
The filter will be surgically cut open today, and pictures posted if I find an issue.
It's the ONLY thing that makes sense to me, I mean if the pressure relief ball/spring and pump filter are in place, the pump is mechanically functional, and the filter isn't restricted, there really isn't much that can cause complete loss of line pressure is there? And the pump noise just adds to the supect of that filter.
Thanks bud, and this thread will live to completion and functionality of the unit in full.
12-29-2012, 03:55 PM
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Well so far it's looking promising.
Here's the filter with the bottom cut off of it. This is right after cutting so there are a lot of plastic chips on the filter media, but I wanted to illustrate it as it was first seen. The pump pickup tube is oriented towards the bottom for reference, take a close look at how the filter media dips upward towards the pickup tube:
Here is a pic of the panel I removed to expose the above media. It's the very bottom of the filter. Notice how it has slats for the filter media to lay on....so why is that front part of the media so pulled up vs. the rest of the filter...
Here is the pickup tube area of the filter, same cut as above just with all the plastic chips washed out via solvent. Take a look at how the media has deformed and is being drawn up into the pickup tube!
This shot is a little out of order vs. the above ones, but illustrates the deflection of the media:
Here I cut the 'neck' of the filter off, the part that goes directly up into the trans pump. It clearly illustrates how the media is being draw up into the limited space in the neck:
Finally, a demonstration of the flow capabilities of the filter element with it all being drawn up into the neck area. It should be noted there are two elements to this filter, sperated by a plastic spacer, so at the neck area that's two element layers drawn together, which greatly cuts flow as illustrated in this video.
This was using generic 141 degree Cleaning Solvent, which is very thin vs. the trans fluid that would need to flow through here on a 10 degree morning:
2012-12-29_14-26-13_764.mp4 - YouTube
I'll wait to call this one whipped till it's back in the truck and operational for a couple of weeks, at which time I will report back. But it SURE looks like this is the root cause. This filter is a parts store filter that was included in a filter/gasket kit and was used as part of a general trans fluid service. The truck had 60k on it and had the original filter/fluid until it was replaced with the above one.
There were no clutch deposits on the filter media, no metal clogging it up. That's part of the reason I took the shot right after I cut it.
I have high hopes, with a GM filter, this problem is resolved.
Here's the filter with the bottom cut off of it. This is right after cutting so there are a lot of plastic chips on the filter media, but I wanted to illustrate it as it was first seen. The pump pickup tube is oriented towards the bottom for reference, take a close look at how the filter media dips upward towards the pickup tube:
Here is a pic of the panel I removed to expose the above media. It's the very bottom of the filter. Notice how it has slats for the filter media to lay on....so why is that front part of the media so pulled up vs. the rest of the filter...
Here is the pickup tube area of the filter, same cut as above just with all the plastic chips washed out via solvent. Take a look at how the media has deformed and is being drawn up into the pickup tube!
This shot is a little out of order vs. the above ones, but illustrates the deflection of the media:
Here I cut the 'neck' of the filter off, the part that goes directly up into the trans pump. It clearly illustrates how the media is being draw up into the limited space in the neck:
Finally, a demonstration of the flow capabilities of the filter element with it all being drawn up into the neck area. It should be noted there are two elements to this filter, sperated by a plastic spacer, so at the neck area that's two element layers drawn together, which greatly cuts flow as illustrated in this video.
This was using generic 141 degree Cleaning Solvent, which is very thin vs. the trans fluid that would need to flow through here on a 10 degree morning:
2012-12-29_14-26-13_764.mp4 - YouTube
I'll wait to call this one whipped till it's back in the truck and operational for a couple of weeks, at which time I will report back. But it SURE looks like this is the root cause. This filter is a parts store filter that was included in a filter/gasket kit and was used as part of a general trans fluid service. The truck had 60k on it and had the original filter/fluid until it was replaced with the above one.
There were no clutch deposits on the filter media, no metal clogging it up. That's part of the reason I took the shot right after I cut it.
I have high hopes, with a GM filter, this problem is resolved.
12-30-2012, 08:56 PM
#5
Yup the interior design of that filter looks exactly like the cheap POS I pulled apart. Like I mention above use one of the three and you will be good to go. Pretty sure filter tech is the OEM filter GM uses and I use spx filters in almost every build I do.
You do have to be careful with some units because the filters are not made in the country of origin the trans comes from. Keep in mind that I build a lot of stuff made in Germany and we make sure to get the right filter. We have found that there are filters made from SPX that are made in china for German units!
Basically a generic brand made for the company but with a cheap filter paper element in them. We see this issue often in ZF5HP24, ZF5HP19 and GM5L40E units in the shop I work for. If there is one place to never go cheap on its the filter! Good find and best of luck with wrapping this thing up. Vince
You do have to be careful with some units because the filters are not made in the country of origin the trans comes from. Keep in mind that I build a lot of stuff made in Germany and we make sure to get the right filter. We have found that there are filters made from SPX that are made in china for German units!
Basically a generic brand made for the company but with a cheap filter paper element in them. We see this issue often in ZF5HP24, ZF5HP19 and GM5L40E units in the shop I work for. If there is one place to never go cheap on its the filter! Good find and best of luck with wrapping this thing up. Vince
12-30-2012, 09:05 PM
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That's intersting to know indeed.
I'll be going to the GM Garage for a filter on this one no doudt. Should have it all wrapped up and installed/pressure tested by this weekend unless the holiday binds up my parts shipments.
Very good information, never have I seen a filter cause this issue....makes me wonder how many of the units I had built over the last few years that had mysterious issues or early failures due to this! I've almost always used a parts store filter on every 60E, THAT is going to change.
At least I know i'm not crazy not being able to find the root cause of the low line PSI upon inspection initially.
Thanks again Vince, i'll let ya know how it turns out.
I'll be going to the GM Garage for a filter on this one no doudt. Should have it all wrapped up and installed/pressure tested by this weekend unless the holiday binds up my parts shipments.
Very good information, never have I seen a filter cause this issue....makes me wonder how many of the units I had built over the last few years that had mysterious issues or early failures due to this! I've almost always used a parts store filter on every 60E, THAT is going to change.
At least I know i'm not crazy not being able to find the root cause of the low line PSI upon inspection initially.
Thanks again Vince, i'll let ya know how it turns out.
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01-04-2013, 11:03 PM
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Hey no problem, i've received a LOT of help from guys on this forum, it's only fair I contribute back once in a while.
All resassembled and ready to go in tomorrow.
Take a look at this GM filter! The design is TOTALLY different in the neck area. You can see a retainer plate keeping the media in place in this pic down the pickup tube:
Closer:
It should also be noted that there is a 'cavity' between where the neck joins the top of the filter body on this GM filter, vs. the other filter which has filter media covering the pickup tube area. You can tell the GM filter is structured in such a way it keeps everything away and retained from entering the pickup tube.
We'll get it back in and a pressure gauge on it tomorrow and see what happens!
All resassembled and ready to go in tomorrow.
Take a look at this GM filter! The design is TOTALLY different in the neck area. You can see a retainer plate keeping the media in place in this pic down the pickup tube:
Closer:
It should also be noted that there is a 'cavity' between where the neck joins the top of the filter body on this GM filter, vs. the other filter which has filter media covering the pickup tube area. You can tell the GM filter is structured in such a way it keeps everything away and retained from entering the pickup tube.
We'll get it back in and a pressure gauge on it tomorrow and see what happens!
