Built 4l80e, no 4th gear
11-14-2011, 08:29 AM
#11
I had this transmission in my 04, and this problem presented itself the same time my engine went out (melted piston). I think they are unrelated, but the timing is curious nonetheless. I sent it back to frank to be fixed under warranty, but in the mean time I found a stock 80e, had it rebuilt by a local shop, and put it in my 04, and it is working perfectly. When I got the trans back from Frank I put it in the corner (with fluid in it) and havent touched it until I put it in my other truck just recently. I probably have 10 very easy miles on it since getting it back and it is doing the exact same thing it was when I sent it off.
Reverse works fine, and the fluid still looks brand new.
What sucks is there isnt a "performance" trans shop anywhere close, and the 80e has to be shipped freight. The closest freight terminal is about an hour away so its a real pain to ship this thing anywhere.
Reverse works fine, and the fluid still looks brand new.
What sucks is there isnt a "performance" trans shop anywhere close, and the 80e has to be shipped freight. The closest freight terminal is about an hour away so its a real pain to ship this thing anywhere.
11-14-2011, 02:23 PM
#14
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Thanks for the heads up... got some house cleaning done! Fire away! LOL....
I don't see that being a problem. It's going to feed the lube circuits regardless of converter clutch valve position so that's not an issue. I would just keep an eye on the temps. I wouldn't let it go that way for too long of a period of time.
Hope that helps... get it fixed mayn!
g
I don't see that being a problem. It's going to feed the lube circuits regardless of converter clutch valve position so that's not an issue. I would just keep an eye on the temps. I wouldn't let it go that way for too long of a period of time.
Hope that helps... get it fixed mayn!
g
02-28-2012, 12:33 AM
#16
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I was asked to post some comments and observations regarding the transmission in this thread based on my own personal experience with it. So here is what I found and what I did to take this unit to a much higher level of performance. To me, it's about leaving it in better shape than when I found it ....
Richard asked me to get involved once he felt like he had expended his original options... and only after we had extensive conversations about his experiences last year did I begin to understand his situation. And once I did understand his situation well, based on my own personal experiences in recent years it became all too familiar. I agreed to take a look at his transmission. I am no stranger to solving problems on transmissions that were built by other companies. But hey, I'm not the only guy I'm sure....
I will say this before I get into the details.... a very good and long time friend of mine who builds very fast chassis race cars for a living has an old saying... " We all know how to fly a helicopter, but no two of us do it the same." High performance racing transmissions are no different. But, the bottom line is what defines us is what we do about it when it gets on our bench or our chassis jig now isn't it? It doesn't matter whether it's a new client, an old lousy client, the best client ever or the hardest job we've ever come across technically... It is what it is and I don't know how to talk about it without calling it like I saw it. I was asked to provide my opinion and was paid to do a job, I did it. And then I was asked to talk about it here by the man who paid me.
Once I got his tranny on the bench I was able to make some determinations quickly... Initially, I did not see any stress in the soft parts... the clutches, bands, and sprags looked okay. Not ideal components for a high performance unit, but okay for a fresh rebuild that would take decent power. The total overall end play was well over .040 front and back combined which was a significant concern for me. There were no extra clutches anywhere that one would expect to see in a high performance unit. There was excessive wear on the rear reaction carrier assembly (the device the low reverse band holds). Enough that I would have replaced it as a matter of course in most any rebuild, and I did on this one. There was excessive metallic debris in the Actuator Feed Limit circuit filter that's located in the valve body... but that's the only place I saw any metallic debris. No debris in the pan nor the main filter and what's interesting is there was no apparent or excessive wear on the rotating assembly thrust washers. Bottom line is, it looked like that filter was missed during a previous repair at some point.
Some clutch packs I saw were nice, but there was a lot left on the table in this build considering what he told me his expectations were vs. what he said he paid for. I am not one to pass judgment, I can only say what I saw. Period. And that is what I was asked to comment on. Just the facts.
Once I got that far it became apparent to me that the problem was in the valve body. After I got my mind around the specific symptom and understood it well, I understood that that the issue was in the AFL valve circuit. Bottom line is what fixed this transmission was reaming the valve body AFL valve bore, installing a Sonnax AFL sleeve and valve assy and replacing some springs at the shift valves themselves.
In addition I was asked to take the unit to a level that would take a punishment, not just get the job done. So, we agreed to make some upgrades along the way. Some I did as a matter of course for signing up for the job, others I recommended and he agreed to.
I will provide supporting pics as I get them downloaded very soon. I have been very busy at the shop for the last several months and just haven't pulled those pics off the camera yet. Not to mention our racing season is firing up down here in Texas and I've been busy gearing up for that with various clients. I will be happy to provide the pics I have of what I saw and what I did to repair this unit with the interest of helping others know how to diagnose similar symptoms in the future.
g
Richard asked me to get involved once he felt like he had expended his original options... and only after we had extensive conversations about his experiences last year did I begin to understand his situation. And once I did understand his situation well, based on my own personal experiences in recent years it became all too familiar. I agreed to take a look at his transmission. I am no stranger to solving problems on transmissions that were built by other companies. But hey, I'm not the only guy I'm sure....
I will say this before I get into the details.... a very good and long time friend of mine who builds very fast chassis race cars for a living has an old saying... " We all know how to fly a helicopter, but no two of us do it the same." High performance racing transmissions are no different. But, the bottom line is what defines us is what we do about it when it gets on our bench or our chassis jig now isn't it? It doesn't matter whether it's a new client, an old lousy client, the best client ever or the hardest job we've ever come across technically... It is what it is and I don't know how to talk about it without calling it like I saw it. I was asked to provide my opinion and was paid to do a job, I did it. And then I was asked to talk about it here by the man who paid me.
Once I got his tranny on the bench I was able to make some determinations quickly... Initially, I did not see any stress in the soft parts... the clutches, bands, and sprags looked okay. Not ideal components for a high performance unit, but okay for a fresh rebuild that would take decent power. The total overall end play was well over .040 front and back combined which was a significant concern for me. There were no extra clutches anywhere that one would expect to see in a high performance unit. There was excessive wear on the rear reaction carrier assembly (the device the low reverse band holds). Enough that I would have replaced it as a matter of course in most any rebuild, and I did on this one. There was excessive metallic debris in the Actuator Feed Limit circuit filter that's located in the valve body... but that's the only place I saw any metallic debris. No debris in the pan nor the main filter and what's interesting is there was no apparent or excessive wear on the rotating assembly thrust washers. Bottom line is, it looked like that filter was missed during a previous repair at some point.
Some clutch packs I saw were nice, but there was a lot left on the table in this build considering what he told me his expectations were vs. what he said he paid for. I am not one to pass judgment, I can only say what I saw. Period. And that is what I was asked to comment on. Just the facts.
Once I got that far it became apparent to me that the problem was in the valve body. After I got my mind around the specific symptom and understood it well, I understood that that the issue was in the AFL valve circuit. Bottom line is what fixed this transmission was reaming the valve body AFL valve bore, installing a Sonnax AFL sleeve and valve assy and replacing some springs at the shift valves themselves.
In addition I was asked to take the unit to a level that would take a punishment, not just get the job done. So, we agreed to make some upgrades along the way. Some I did as a matter of course for signing up for the job, others I recommended and he agreed to.
I will provide supporting pics as I get them downloaded very soon. I have been very busy at the shop for the last several months and just haven't pulled those pics off the camera yet. Not to mention our racing season is firing up down here in Texas and I've been busy gearing up for that with various clients. I will be happy to provide the pics I have of what I saw and what I did to repair this unit with the interest of helping others know how to diagnose similar symptoms in the future.
g
02-28-2012, 11:08 PM
#17
Also, as Gilbert mentioned in one of our conversations, it wasnt actually "netrualling out", it was shifting back to 1st gear. I was never going fast enough for this to be an issue for fear of causing further damage, and anyone that has driven a loose torque converter at high rpm in a low gear knows when you are off the gas it feels like netrual. Also, Jake, that is why the computer saw it as TCC slip and not trans slip.
Last edited by Atomic; 02-29-2012 at 11:06 PM.
05-03-2013, 02:50 PM
#19
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Tranny Issue
I have a similar problem, I have a 93 Suburban 2500 with the 4L80E and sometimes it just randomly shifts to 3rd gear, I lose over drive often and its killing me. I took it to a tranny shop and they want to rebuild it, but I absolutely don't have $2500 for a rebuild. Are there some things I can change out to solve this issue or am I just going to have to put money in the little piggy and take a hammer to it after the tranny craps on me. Any help would be great.
A little side note. I changed the Transmission Speed Sensor and the tranny worked great for about 400 miles. After that it resorted right back to its slippery ways. What could have caused such a dramatic change, with such a small part? Why would it resort back to losing overdrive after 400 miles? Again any help would be great.
A little side note. I changed the Transmission Speed Sensor and the tranny worked great for about 400 miles. After that it resorted right back to its slippery ways. What could have caused such a dramatic change, with such a small part? Why would it resort back to losing overdrive after 400 miles? Again any help would be great.
05-05-2013, 08:22 AM
#20
I know Atomic's situation all to well and Gil and I had a few conversations concerning that unit. As Gil mentioned above the 1-2 shift valve spring is a huge issue in these units. Also the AFL circuit is one to look at closely. Here is a part number from sonnax that will help to address this issue with the 1-2 shift valve spring. Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts
What happens is after the 1-2 shift oil for the other gears is constantly feed through this circuit. If for any reason that 1-2 valve starts to stroke when it should not that is when you will feel that neutral condition. AFL oil is also used to keep this valve in its required position. In the units I build I will either use the sonnax kit mentioned above or use a TTK overhaul kit which comes with a spring for the 1-2 shift valve.
Stephen I know buying a transmission can be expensive. Depending on the condition of the unit it might be able to be saved but you are rolling the dice here so to speak. If it were my truck and I did not want to pull the trans. I would pull the pan first to see the condition of it. Looking for debris and what not will tell us if the unit has already been compromised or not.
If all appears to be well I would pull the valve body to freshen it up. By doing this we can check for wear in this assembly and possibly fix the issue. A new separator plate, torlon check *****, shift valve springs, AFL valve and the tcc valve would all be ones that I would inspect/replace.
To address the the AFL issues this will require a reamer. Most good trans shops will have this tool. Or the hole in the separator plate can be enlarged to about .045 and possibly help prolong this issue. Another thing to look at is the boost valve for wear. This is what helps control pressure and lets face it we have fluid pressure issues in most cases.
I hope this helps you some and also a little understanding of the issue at hand. Vince
What happens is after the 1-2 shift oil for the other gears is constantly feed through this circuit. If for any reason that 1-2 valve starts to stroke when it should not that is when you will feel that neutral condition. AFL oil is also used to keep this valve in its required position. In the units I build I will either use the sonnax kit mentioned above or use a TTK overhaul kit which comes with a spring for the 1-2 shift valve.
Stephen I know buying a transmission can be expensive. Depending on the condition of the unit it might be able to be saved but you are rolling the dice here so to speak. If it were my truck and I did not want to pull the trans. I would pull the pan first to see the condition of it. Looking for debris and what not will tell us if the unit has already been compromised or not.
If all appears to be well I would pull the valve body to freshen it up. By doing this we can check for wear in this assembly and possibly fix the issue. A new separator plate, torlon check *****, shift valve springs, AFL valve and the tcc valve would all be ones that I would inspect/replace.
To address the the AFL issues this will require a reamer. Most good trans shops will have this tool. Or the hole in the separator plate can be enlarged to about .045 and possibly help prolong this issue. Another thing to look at is the boost valve for wear. This is what helps control pressure and lets face it we have fluid pressure issues in most cases.
I hope this helps you some and also a little understanding of the issue at hand. Vince
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