Bogs and wont downshift when hot. Please help.


Active Member
Sep 9, 2004
Starting about a month after putting a D-5 in, I started getting this problem. Tranny used to have a non lock TC in it, and I dont know what the prior owner did to prep it for a non lock TC. When I first got it in, I could get the TC to lock at low rpms and high load with a TC switch. Every other component is correct...voltage, switch, everything. They may have a non lock pump valve in it, but if that were true, why could I get it to lock at low rpms and high load?
Anyway the problem is, that after driving for 1/2 hour, the tranny will not downshift when I give it alot of gas, in every gear but first. The engine bogs way down. It bogs harder the more gas I give it. It wont downshift. Boost goes up, load goes through the roof, but it wont downshift. The TV cable is set right and shift points are fine. Someone mentioned the TC solenoid is going out, but lockup has only worked since installing the D-5, when Im climbing a steep hill in OD. Once Im over the hill, the rpms go back up while I cruise. It locks up every time, (or maybe something else is mimicking lockup?) when I go up a hill, but never the rest of the time. Now imagine that I have a lockup pump valve in it, and the solenoid ohms fine. What could cause this heat related issue? My engine coolant temps used to soar when climbing hills when I had the non lock TC in there. After the D-5, everything runs cool.
Million dollar question- Does the tranny fluid pump through the lines and into the radiator when lockup is NOT working? From what i understand, when lockup happens, a circuit opens and allows the tranny fluid to flow through the cooler. The rest of the time it is not flowing through the cooler lines. If I have no lockup, could my tranny be smoking hot and causing issues? Imagine it is getting hot...what is it about getting hot that would cause the bogging and no downshift issue Im talking about?
Man....... Not good....

First step is to MAKE sure the lock up valve and springs are in right and ARE THERE!!! If the non lock valve is still in there and you are running lock up, bad scene man. You should pull pan immediatly and pull TC solenoid and ck.
If not, install right away and hope you didn't hurt anything. If when you get back to us with this question, we can go onto more of what may be happening or what has already taken place.I will say, if the non lock valve is still in there, we got problems now.
You can always call the shop if needed.
Thanks! Ill give you a call probably next week. Can you shed some light as to whats so bad about it? Ive put probably 8000 miles on the car since I swapped converters. It still gets me down the road and hauls ass. It just develops this problem after driving for awhile. Youve got me pretty worried. No one has ever said its really bad, and if they did, never explained why. Im wondering if it has a non lock valve, why does it lock up every time I climb this mountain range on the way to work every day? The guy I bought a 9-11 converter from said he was going to send me a lockup valve setup after i sent him the check for the converter, but it never came, and I lost his contact info. Can I get this from Art Carr? I could pull the pan on my tranny, but unfortunately I dont know much about trannies. I know where the solenoid is from pictures, but I wouldnt know a lockup valve from a non lock valve, or what all the components are or how they get installed. Having some pics would help alot, but Ive never been able to find something real to look at on the net. I dont even know if the existing solenoid is wired up right. From the pics Ive seen, there are 2 red how would you know which one goes where? The previous owner had the purple power wire removed from the connector on the side of the tranny. I figured if you have a non lock valve in there, why would you need to pull this wire out? I was thinking maybe he just disabled lockup electrically....or is this even a possible way to do it? Should I pull this wire back out right away? The people at autozone or kragen have no idea what this valve is, so its not like I can do it this weekend.