I have exhausted my forum and google searches on this issue. Nothing posted is consisted with my issue. Problem:

First, when everything is working properly, Ive counted 4 shifts. 1-2, 2-3, 3-4, and then overdrive. Now, I've understood these transmissions are 4 speeds and fourth gear is overdrive. I figure the 4th "shift" is really just the TC locking in and dropping the rpm's another 300 points or so.
When cold, I will get onto highway or interstate and the transmission (has HD2 kit) will shift perfectly through the gears. Once in 4th, (when cold) it feels like the TC is trying to lock into the final drive but fails, kicks out, then tries again........over and over again. Feels like a brief power loss, but I can maintain my throttle position and speed while specifically observing my tach bounce up and down approximately 200-300 rpm. The rpm change is consistent with the drop I would expect to see when the TC locks up.

Anyone know if this is a TCU issue, speed sensor, TC, tranny solenoid, etc? Thanks! Hoping its something I can remedy myself.

Other info. Don't recall the tranny doing this before the HD2. BUT, it started doing it well after the shift kit was installed, so I don't see a relationship.

Running Amsoil fluid. Fluid is up to level and looking good.

 

How long have you been running the AMS? I swear these trannys hate when you change fluid on them and can do all sorts of crazy things when you do but it usually settles down. Either that or mine is just weird

 

Running since I did the HD2. Both happened at the same time.

 

It sounds like the same issue that's referenced in the 3rd gen manual:



Normal when warm? I think it may be by design. Kind of like an open loop/closed loop thing except for the trans. It needs to get up to temp.

 

And I thought that too. Only thing that threw me was my understanding 4th is overdrive (which it always goes into smoothly, even cold) and my issue seems to center on the TC kicking in after being in fourth.

If it is actually overdrive kicking in/out when cold, that means I would have a 5 speed auto..... which doesn't exist on this car that I know of. I will take a video tonight. It will be dark, but you really just need to see the tach and hear the engine.

But, Reizy, it does seem temp related, but didnt do this last winter, so it is something new. And i want to say the car is warmed up and it still does it, just in cold wheather. In any case, when cold I may do as suggested and just drive in 3rd for the first 15 minutes. I will also check my e-Manual on the computer (forgot I had till this very moment) and see if it also mentions this condition. Thanks!

 

4th has overdrive, yes. At least in my 4th gen, the "shift maps" for a lack of a better term are different when overdrive is on vs off. I can turn OD off when I am going 30 MPH (3rd gear) and my rpms will rise.

I think that when OD is turned on, the Torque converter will attempt to lock itself when you're maintaing speed at any gear (for the fuel efficiency)...even in 3rd. I notice no TC action whatsoever when OD is off.

Therefore, I think OD an the TC are working together...so if OD is fritzing because your car's not warmed up...then your TC fritzing is a symptom of that as well.

Try it out...run around town to warm up the engine fully and then hit the highway.

 

Im having pretty much the same problem as you described but I dont think I have seen my tach bounce as you mentioned. i'm planning to do a filter and ATF change and see if adding a cooler helps. Mine does it when warmed up. I tried doing the self diagnosis for the TCM as listed in the repair manual but my tps needs adjusting at closed position so it won't go into self diagnosis. Found this out after tourbleshooting why it didnt by checking the the TPS, OD switch and park/neutral switch at the TCM as outlined in the manual. I don't think the tps needing adjustment for its closed value would cause the problem. I might adjust it and see if the self diagnosis picks up anything.

 

Keep in mind I have a 5.5 and no OD switch, just the shifter.

Here are the videos. First is from start and getting up on interstate. Video shows shifts through 4th, which is smooth as always. Video ended cause someone called me.

http://i1174.photobucket.com/albums/...53517D367E.mp4

The second vid is right after the call. I drop down into 3rd then back to drive just to recreate shifts. Then the TC clearly kicks in and rpms drop from about 3300 rpm to 3000 rpm. Of course it worked fine. Will take another video tomorrow. Couldn't avoid the car being warmed up tonight by the time I hit the interstate. But, these vids should give good reference for when it is working for when I can show when it isn't!

http://i1174.photobucket.com/albums/...536C779C55.mp4

Sorry, forgot how to link vids....don't do it often enough. Will edit if they fail.

 

Just caught it doing it again. Accelerated a moment then let off and it went right back into it.

http://i1174.photobucket.com/albums/...DD529F5E3D.mp4

 

I'm dealing with same problem, I live in MN. Get anything figured out?

 

What's your tach say right around 60 mph with this problem?

 

Learned it is normal function of tranny. It's simply the TC trying to kick in bit can't or won't when tranny not warmed up yet the car is driven at high speeds. Seems does it most when leaving work and hit the interstate within 30 seconds. Even if car warm, seems tranny temp doesn't reach operating emperature until sometime after the dash guage reads warmed up. If it continues this summer, I may look into it further such as new TC and/or shift solinoids. No longer a concern, just keeping an eye on it.