Converter lockup backwards?
Well, bad news, gounding out the PWM pin only worked for a while. Its back to doing the same thing. I was datalogging the computer and it did not seem to be doing anything. The TCC lockup was not showing even when it was locked up. This is driving me nuts. I took the harness out and both TCC and PWM solenoid wires are good, not touching anything else and I yanked all over the harness to make sure. I'm going to try a PCM next. I'd like to rule that out. I can't see how I turn off the TCC solenoid and everything works right. Commanding it on has no effect at all. Only off. Computer, then tcc, pwm solenoids and probably a valvebody while I'm in there. There is a local place that does valvebodies, if they have one that is already done with sonnax stuff I may try that first. Got a feeling its computer. Nothing mech can explain the backwards operation to me.
Ok, update for anyone who cares. If nothing else I get to hear myself think and possibly come up with an idea. Car still acting up. With new fluid and when the tranny is cold it works fine. Little bit of heat in the fluid and it fails. Trans temps are in the 140s so I know its not too hot.
Datalogging, I see the computer commanding the TCC to lock. When it bounces out, I see no change in any of the status bits. Computer still showing the lock commands, still shows the TCC activated. No changes whatsoever. This leads me to believe its pressure related. So, instead of the computer I'm going to try the valve body and all new solenoids. Today I did get a couple of P1870s, which I did not get before but I was screwing with the lock command.
Based on the good performance when cold, that fact that no computer inputs are directing this and the fact that now and again I see a P1870, even though I'm doing it with the commands, my best guess is valve body. I guess I'll see when it comes in.
Oh, also, for people looking for a 98 computer they are rather hard to come by. $300 for a flashed one vice $89 for the 99-00 ones. That plus a $150 core is pretty steep. If I could be out for $89 I would throw a computer at it, but for that kind of money I'm going to hold off.
By the way, sending the unlock command to the TCC solenoid still locks the clutch (I assume) and drops rpms. This is only when its unlocking when it shouldn't. If I send the unlock command when its working correctly it does in fact unlock and raise rpms. Other way around when its goofy.
Datalogging, I see the computer commanding the TCC to lock. When it bounces out, I see no change in any of the status bits. Computer still showing the lock commands, still shows the TCC activated. No changes whatsoever. This leads me to believe its pressure related. So, instead of the computer I'm going to try the valve body and all new solenoids. Today I did get a couple of P1870s, which I did not get before but I was screwing with the lock command.
Based on the good performance when cold, that fact that no computer inputs are directing this and the fact that now and again I see a P1870, even though I'm doing it with the commands, my best guess is valve body. I guess I'll see when it comes in.
Oh, also, for people looking for a 98 computer they are rather hard to come by. $300 for a flashed one vice $89 for the 99-00 ones. That plus a $150 core is pretty steep. If I could be out for $89 I would throw a computer at it, but for that kind of money I'm going to hold off.
By the way, sending the unlock command to the TCC solenoid still locks the clutch (I assume) and drops rpms. This is only when its unlocking when it shouldn't. If I send the unlock command when its working correctly it does in fact unlock and raise rpms. Other way around when its goofy.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Thanks for the detailed post. Certainly I and probably others are learning from this.
The OP of another thread also mentioned the high price for '98 PCMs. (I sold one last year.) As you may know, you can change to a '99-'02 PCM if you are willing to rewire the connectors. I have done this - I first bought new connectors so that I could move the wires one-by-one from the old location to their new location in the new connector. There is a thread on Ls1tech with the step by step directions. I switched to a '02 PCM; one nice thing about that year is that it has 48 bits of logging (instead of just 24) so that you can log many more parameters at once.
The OP of another thread also mentioned the high price for '98 PCMs. (I sold one last year.) As you may know, you can change to a '99-'02 PCM if you are willing to rewire the connectors. I have done this - I first bought new connectors so that I could move the wires one-by-one from the old location to their new location in the new connector. There is a thread on Ls1tech with the step by step directions. I switched to a '02 PCM; one nice thing about that year is that it has 48 bits of logging (instead of just 24) so that you can log many more parameters at once.
Joe, I'm hoping its the apply solenoid and or its bore. There is a slim chance it could be the pump, I've talked to some people and it a very rare break. However, with my luck...
Valve body and all solenoids will be next week. I'll post up what happens. I may be heartbroken if this don't work.
Valve body and all solenoids will be next week. I'll post up what happens. I may be heartbroken if this don't work.
Ok, so I'm showing my ignorance. I took the accumulator out and the piston in the housing on the valve body side had 2 springs and the piston on the trans case side had none?
Every pic I have ever seen had a spring on both sides. Is this a mod? I'm not sure how the hell to put it back together. Off to do some seaching. If you have any input save me some trouble! lol
Every pic I have ever seen had a spring on both sides. Is this a mod? I'm not sure how the hell to put it back together. Off to do some seaching. If you have any input save me some trouble! lol
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Ok, looks like there is supposed to be 2 stock on the bottom, and one on the top (which I'm finding out may be 4th). I'm SOL until I find one for the top. Maybe my dumb luck has it fallen in the catch pan. I'm pretty careful watching and I'm only one beer in but stranger things have happened.
*edit, there is and was no spring in the piston closest to the case. Not sure if this is supposed to be some "mod" or just that some idiot put this back together. So, I guess I got to wait until I find an answer. I've looked everywhere just in case and there was no spring. When I took the seperator plate off I was surprized there was no pressure. Also, when you look at the seperator plate you can clearly see where the "****" of the pison were resting on the plate. It left marks. If the spring was there the piston shouldn't contact the plate if my logic is correct. Maybe this is some kind fo shift mod. I've got to go friggin search.
*edit, there is and was no spring in the piston closest to the case. Not sure if this is supposed to be some "mod" or just that some idiot put this back together. So, I guess I got to wait until I find an answer. I've looked everywhere just in case and there was no spring. When I took the seperator plate off I was surprized there was no pressure. Also, when you look at the seperator plate you can clearly see where the "****" of the pison were resting on the plate. It left marks. If the spring was there the piston shouldn't contact the plate if my logic is correct. Maybe this is some kind fo shift mod. I've got to go friggin search.
Last edited by AintQik; Nov 21, 2013 at 08:28 PM.
Well for prosperity lets say that the 4th accumulator is sometimes installed without a spring. I think you are supposed to block the port when u do that but he'll I dunno what has been done in there. I'm about to just go buy another whole tranny. However since I have no spring, don't really feel like waiting on a spring, I guess I will put it back together the way it was. Unless one of you all correct me, I don't think that accumulator has any effect on the TCC lockup. At least I can see if this helps. I keep dumping burnt fluid out, so I think the whole damn thing is gone, but the shifts were always good. Still hoping for a save. On the Brit side it gets a little pinker each dump lol.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
The 4th accumulator spring on the (at least later model) 4L60E is under the piston. Did you pull the piston out yet to look for the spring? Any local trans shop would like have a few spares.
But you are right - these accumulators won't have any effect on the TCC. Make sure the TCC valve moves smoothly - not stuck and not loose in its bore. Or just replace it with a Fitzall on/off valve.
But you are right - these accumulators won't have any effect on the TCC. Make sure the TCC valve moves smoothly - not stuck and not loose in its bore. Or just replace it with a Fitzall on/off valve.
Yup pulled it out and there is no spring. I can't get to 4th without taking the separator plate off so I have to figure out what to do. 3-4 seemed ok, nothing really dramatic either way. From the marks on the plate I can confirm there never was a spring, I just don't want to put it together only to take it apart again. I also don't know if anything else was done to the trans. This is looking more and more like a swap. If it shifted ok before and I'm reasonably certain there was no spring there and it has no effect on the converter I guess I will put it back the way it came and see what happens.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
There is accumulator pressure on the side of each piston closest to the separator plate. The clutch apply pressure is then on the other side of piston. In the 1-2 accumulator the springs help press against the accumulator pressure. IIRC the 700R4 had the 4th spring on the separator plate side while the 4l60E has it on the opposite side. Its a weak spring; it probably doesn't matter much which side it is on and even if there is one at all. But you absolutely do need to keep the piston in there.
Also remember the checkball in the case near the 4th accumulator. Use Vaseline to hold it in place.
Also remember the checkball in the case near the 4th accumulator. Use Vaseline to hold it in place.
Installed the valve body, new solenoids. Ran perfect for 40 minutes. Then at around 60mph it started acting up. I hope its somthing I can tune, I put the stock tune back in. But, I doubt it lol 
Most of the 40 mins was at 50, right when I got to speed up it started acting wierd. We'll see, but the outlook is not good.
I was sure damn happy for 40 minutes tho lol!
Most of the 40 mins was at 50, right when I got to speed up it started acting wierd. We'll see, but the outlook is not good.I was sure damn happy for 40 minutes tho lol!
Well, fluid is fresh and topped off, and I screwed with the tune a bunch. After 15 minutes it starts slipping. Its about 100 times better with the new valve body but it still unlocks and or slips. With the new valve body and noids i can burp the throttle and get it to lock back up. Stays that way for a few minutes then flares up and slips again. Cold, it works like a champ. Get some heat in it and it just starts acting up. Scanner indicates no change in PCM commands. No other indications in the data log. Screw it I'm done. I'm going to swap the tranny and verter. If its still there i will swap PCMs, but its mech/pressure related I'm about sure.
Performabuilt? They are close to me. Happy Christmas to me! LOL I'm active duty military and 2 months from retirement. I sold all my daily drivers and figured i can just drive the 98 until I find a job. Well, that didn't work out too well. Ah well, such is life.
Performabuilt? They are close to me. Happy Christmas to me! LOL I'm active duty military and 2 months from retirement. I sold all my daily drivers and figured i can just drive the 98 until I find a job. Well, that didn't work out too well. Ah well, such is life.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
When you say slipping, do you mean the TCC lockup is slipping?
By "new valve body" do you mean you overhauled it or is it a new/rebuilt unit?
If just the TCC is slipping, I would get a Fitzall valve for the TCC; it is only $15 and only requires removing the VB which you are an expert at now.
It can take the trans a good 15+ minutes (longer in the cold) to fully warm up at which point line pressure drops a bit due to the warmer oil. So it sounds like something is marginal, works with higher line pressure but not with normal line pressure.
By "new valve body" do you mean you overhauled it or is it a new/rebuilt unit?
If just the TCC is slipping, I would get a Fitzall valve for the TCC; it is only $15 and only requires removing the VB which you are an expert at now.
It can take the trans a good 15+ minutes (longer in the cold) to fully warm up at which point line pressure drops a bit due to the warmer oil. So it sounds like something is marginal, works with higher line pressure but not with normal line pressure.
Yes, it feels like the TCC is slipping. The valve body is rebuilt by a good shop and they sleaved the TCC PWM and gave me all new noids. Also swapped harness and TCC solenoid and installed a Transgo seperator plate. I have no idea what a Fitzall is, I guess I will have to go do some more research. I'm not looking forward to dumping the valve body again. Since both the tranny and converter have an unknown history Im not sure I even want to keep going. However, I'll give this Fitzall you speak of some research Sound like a Finnigin Pin to me.
With the new VB, it works much, much better/different. But it ultimately will slip when locked. I've got the PWM tuned out and the TCC hits on and off pretty hard and I don't really feel that when it "unlocks" now. So, I'm leaning on the TCC slipping. For whatever reason when I still command the TCC sol "off" it will grab and drop RPM.
Thanks for the advice. I'm going to keep plugging away.
Sound like a Finnigin Pin to me. With the new VB, it works much, much better/different. But it ultimately will slip when locked. I've got the PWM tuned out and the TCC hits on and off pretty hard and I don't really feel that when it "unlocks" now. So, I'm leaning on the TCC slipping. For whatever reason when I still command the TCC sol "off" it will grab and drop RPM.
Thanks for the advice. I'm going to keep plugging away.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Since you say the VB was rebuilt and the TCC PWM sleaved, there is no need for the Fitzall valve. It could just be that the lockup clutch in the converter is too worn to hold lockup.
But you say that the TCC on/off is still reversed? You command OFF and it turns on and drops RPM? Wow! Did you replace the main TCC solenoid, the long one that fits into the pump?
But you say that the TCC on/off is still reversed? You command OFF and it turns on and drops RPM? Wow! Did you replace the main TCC solenoid, the long one that fits into the pump?
Yes when I command it off the rpms drop just like before. Maybe I need to see how a TC works. Maybe the clutch is so bad that turning it off allows rpm to drop by going back vane to vane. This really makes no sense as I imagine the clutch works with the hydraulics not independently but I have no idea. If it is slipping that bad I'm not going to replace the converter because there will be crap all thought the trans. I will do both. I do have a stock beat up converter I can throw in to see if it works but man that is a bunch of work. Maybe if I feel froggy I will do that tomorrow for the sake of prosperity.
It can't be 4th slipping? It shifts reasonably well and I don't think shutting the tcc off would make it stop. Got to be pressure or the verter.
Oh and yes I put a new harness and TCC lockup noid in that was tested and good. Unless the computer is doing something that does not show up it the status bits, it's got to be pressure or the TCC. It will hold when cold and at lower rpm and speed.
It can't be 4th slipping? It shifts reasonably well and I don't think shutting the tcc off would make it stop. Got to be pressure or the verter.
Oh and yes I put a new harness and TCC lockup noid in that was tested and good. Unless the computer is doing something that does not show up it the status bits, it's got to be pressure or the TCC. It will hold when cold and at lower rpm and speed.