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The valve body I bought is older and has one difference that I can see. And Sonnax has it listed on their site as well. The screen shot I am attaching to this shows the differences between them. If you think I can swap the VBs out and test the older one, let me know. I have the bottom one installed (original) and the top one is the older one I just bought.
1995 is a one year only VB, not sure if it would work or not but I would just fix your VB. You are really shooting in the dark here without vac or pressure testing. your VB could be worn beyond a drop in fix. do you have access to another PCM? Might be a thought to rule out it out.
1995 is a one year only VB, not sure if it would work or not but I would just fix your VB. You are really shooting in the dark here without vac or pressure testing. your VB could be worn beyond a drop in fix. do you have access to another PCM? Might be a thought to rule out it out.
Are you saying the Same type PCM, or newer? Either way, I dont have one currently.
I will be taking the trans out and getting the pump out. I have checked all the valves many times and dont see anything wrong with them at this point. Putting in the boost valve, PR valve and AFL valve were the only things that I know of that can effect the pressure. EPC was replaced many times as well. If I have updates to this, I will post them on here for everyone to see.
At this point I believe the pump is either bad or maybe, a 10 vane was put in instead of a 13 vane. I have a lot to look up and get familiar with.
At this point I believe the pump is either bad or maybe, a 10 vane was put in instead of a 13 vane. I have a lot to look up and get familiar with.
doubt it, going to a 10 vane is a common performance "upgrade". i would try a pcm before rebuilding the trans. would be a shame to rebuild it and have the exact same problem. a 411 pcm swap is a common upgrade for the GMT400 truck crowd.
doubt it, going to a 10 vane is a common performance "upgrade". i would try a pcm before rebuilding the trans. would be a shame to rebuild it and have the exact same problem. a 411 pcm swap is a common upgrade for the GMT400 truck crowd.
Thats a pretty big change. I also dont understand how the PCM would be giving me problems after the rebuild.
weren't you having these problems before your rebuild? sorry I don't have time to reread 5 pages... i dont know what your plans are for the truck. if you are wanting to tune the '411 has a lot more options than the "black box" you have. after all the work you have done what are the issues now?
weren't you having these problems before your rebuild? sorry I don't have time to reread 5 pages... i dont know what your plans are for the truck. if you are wanting to tune the '411 has a lot more options than the "black box" you have. after all the work you have done what are the issues now?
EDIT: Sorry, i see it has 30 Psi @ hot idle now.
correct. I did not have these issues before the rebuild. Everything was fine. And yes, pressure gets very low while hot with a bad engagement issues from stop and in reverse. Pressure rises slightly and stays there and then jumps higher. When it jumps higher is when it feels like it really kicks into gear. Before the kick, it feels as if its hung up and I am at a "half power" state (dont know how else to put it). Also when in 4th, it jumps around as if lock up is going in and out. With all the VB and pump changes I made, all it has done is made it more pronounced.
Was this a DIY rebuild or buy a shop? I wonder if the correct separator plate and/or gaskets were used? even if the gaskets were installed incorrectly can cause weird issues. I am guilty of this myself. Did a shift kit in a Cherokee a while back and thing drove really weird, partially in gear, etc. turns out i installed the 2 gaskets on the opposite sides....
EDIT: did you install the Fitzall valve to delete PWM lockup? if so what part number did you use?
Was this a DIY rebuild or buy a shop? I wonder if the correct separator plate and/or gaskets were used? even if the gaskets were installed incorrectly can cause weird issues. I am guilty of this myself. Did a shift kit in a Cherokee a while back and thing drove really weird, partially in gear, etc. turns out i installed the 2 gaskets on the opposite sides....
EDIT: did you install the Fitzall valve to delete PWM lockup? if so what part number did you use?
The rebuild was done by a locals guy. He hasn’t been able to work on/refusing to work on it.
I don’t know exactly what to look for as far as separator plate and gaskets go.
I also don’t believe Fitzall was used. It looked like a Sonnax valve if I’m not mistaking.
Sounds like they put Transgo HD2 kit in? It should have the transgo valve then. Have you done basic things like adjust the shift linkage properly? I know you had a scan tool did you verify TPS, MAF, etc was working correctly. I am trying to think of easy things to check before pulling the unit. it may be worth dropping valve body and checking each valve line up to make sure everything is installed correctly..you will also need to reference the transgo instructions.
I read back some and noticed the pics you posted of a scantool. Did anyone else notice this?
It should not be in "Hot mode"....
Good catch. I suspect this turns on if the ECU reads an excessive trans temp?
atlsoldier27: Connect a scanner to show you the trans temp. Perhaps it is falsely reading something like 250+F. The manifold pressure switch produces this value; perhaps it or the wiring is bad. I'm not sure this is your only problem, but it needs to be resolved. (Of course the scanner could be reporting it incorrectly, but the trans temp is available via OBD2.)
Tayto: We ruled out the MAF because the OP disconnected it and it made no difference. The MAP values look fine to me in the pictures he posted.
looks like it has the correct lower valve body gasket (round hole not square). not sure if you peeled the gaskets back, but they should not have a white stripe on them.
The transmission hot signal was switching on/off the whole time. The scanner I put on didn’t read any temp value either, it said N/A like it had with a lot of other data. I have another pressure switch from the VB I had purchased last week. I could try it and see. During which time, I could give the gaskets a check, but I’m pretty sure the top one had no writing on the back of it.
as far as all the valves go, I did check all of them, took it all apart and nothing seemed wrong or stuck. I have a printed diagram of all the valves for each bore. Compared and made sure it was installed correctly and everything.
when hot mode is on it will inhibit 4th gear so this might explain why it you are dropping in and out of high gear. i think the pressure switch (which also has temp sensor on 4L60E) is a good place to start. with a scanner you should be able able to see what the pressure switch is doing. i would also check the internal trans harness for continuity while you have the pan dropped. do you know if the builder installed a new harness? if you see atf when you remoce the connector, it should be replaced. ones made by Rosta are inexpensive: https://www.rockauto.com/en/moreinfo.php?pk=10319952
when hot mode is on it will inhibit 4th gear so this might explain why it you are dropping in and out of high gear. i think the pressure switch (which also has temp sensor on 4L60E) is a good place to start. with a scanner you should be able able to see what the pressure switch is doing. i would also check the internal trans harness for continuity while you have the pan dropped. do you know if the builder installed a new harness? if you see atf when you remoce the connector, it should be replaced. ones made by Rosta are inexpensive: https://www.rockauto.com/en/moreinfo...44303&pt=12391
I was not told if he did or not, however, it does not look new. I did not see any fluid in the connector at all. The pressure switch on the other VB is an older one as it does not have the cover on the back that they added to stop shorts from happening. I had cleaned my switch the first go around with all of this, but I will try the other one and see what happens. What youre saying does make sense, as the scanner had shown "hot mode" on/off every few seconds. not sure if that would have anything to do with the low pressure issues though.
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