Torque Converter "Flutter"

[ltd02]

Disclaimer: I don't know much about transmissions (among many other things). I searched but can't seem to find my issue described accurately anywhere, including the big three forums, so here goes. I've had this ongoing problem/characteristic for as long as I've owned my KJ (>80k) but it seems to have gotten much worse this week. I'd have to describe it as a subtle but detectable flutter under light load, most noticeable (even with CC on) on the highway. Seems like the TC can't decide whether to lock or not. I've noticed it when cruising at a steady speed anywhere from 50-75mph. As soon as you hit a slight incline the flutter occurs very reproducibly now but was intermittent until about a month ago. Even noticed it last night when topping a hill at about 45mph when it upshifted to what I'd assume is 4th. I think I've heard the TC is supposed to lock up around 62mph and I believe I can sense this happening but not sure if it is fully locking. If that is even possible?

More info:

No codes

Heavy load or acceleration is nothing but good.

168k

45RFE

Fluid is full and about 7k on it since pan drop and filter change (only ATF+4)

Doesn't feel at all violent like the CRD guys describe with the TC shudder.

As long as I've owned it I have also had the following issue:

http://www.jeepkj.com/forum/f196/weird-overdrive-behaviour-50737/

Maybe I'm all wrong and my bulletproof 45RFE is toast?

Any and all help is greatly appreciated. :shrug:

 

[LibertyTC]

When you checked for PCM codes, what scanner did you use?

 

[ltd02]

When you checked for PCM codes, what scanner did you use?

I used my OTC 9450. Now that you mention it I should check to see if it can read ****** codes. I don't see why it wouldn't but never confirmed it in the manual. Nothing showed up and of course no CEL. Tried the Actron pocket scan too but that isn't very sophisticated.

Edit: I see it supports OBDII and CAN "generic" codes. I wonder if this is an issue? Are the ****** codes Manufacturer specific?

 

[LibertyTC]

Ya I don't think your generic scanner is able to view the stored or history of PCM codes.
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My last scan included using the latest $7k SnapOn.
The database is vehicle specific, and you program in the actual vehicle.
Generally a high end shop scanner is needed.

 

[libertybob]

Torque Converter Clutch

Could be your torque converter clutch is starting to go. Will eventually set a P0740 code, torque converter clutch circuit malfunction. Did you find any clutch material in the pan or filter when you changed fluid? Torque converter clutches are a common problem. Jeep had a recall on these in 2003. Had to replace mine. If you get a P0740 code and the transmission still functions ok, stop driving the vehicle and change out the torque converter. If caught early, no lasting damage. If continue to drive with failed TCC, clutch material will clog trans requiring a rebuild.

 

[ltd02]

Thanks for all the replies. Well I guess I could schedule my recall visit now and have them scan it while in there. Have to have them check my airbag light issue anyway. Last time they were pretty reasonable.

No material in the pan when fluid was last changed. Like I said this has been getting much worse very recently. I wonder if mines been changed as I got it with 80k on it.

 

[libertybob]

Torque Converter Clutch

Could be your torque converter clutch is starting to go. Will eventually set a P0740 code, torque converter clutch circuit malfunction. Did you find any clutch material in the pan or filter when you changed fluid? Torque converter clutches are a common problem. Jeep had a recall on these in 2003. Had to replace mine. If you get a P0740 code and the transmission still functions ok, stop driving the vehicle and change out the torque converter. If caught early, no lasting damage. If continue to drive with failed TCC, clutch material will clog trans requiring a rebuild.

The flutter you refer to sounds like the torque converter clutch slipping, an early sign of TCC failure. Mine failed at 173k and you're at 162k. Hmmm...

 

[ltd02]

Could be your torque converter clutch is starting to go. Will eventually set a P0740 code, torque converter clutch circuit malfunction. Did you find any clutch material in the pan or filter when you changed fluid? Torque converter clutches are a common problem. Jeep had a recall on these in 2003. Had to replace mine. If you get a P0740 code and the transmission still functions ok, stop driving the vehicle and change out the torque converter. If caught early, no lasting damage. If continue to drive with failed TCC, clutch material will clog trans requiring a rebuild.

The flutter you refer to sounds like the torque converter clutch slipping, an early sign of TCC failure. Mine failed at 173k and you're at 162k. Hmmm...

We've got some pretty compelling similarities. Weird though since I distinctly remember it doing this shortly after getting the vehicle well over 80k ago. Guess I've been lucky!

Is there any way to temporarily disable the TCC solenoid? I did this to my 93 Grand Am by simply unplugging it from the side of the trans. It wouldn't unlock once locked, so not good for it but at least I didn't stall every time I came to a stop after it had locked.

 

[604KJ]

I just had my tc replaced. It was shifting like yours and just got worse and worse over about 8 months, kept getting stuck in gear. The shop said my tc was throwing bits of metal around and it damaged other parts. You should probably have it looked at now before it gets worse and the rebuild is more expensive.

 

[ltd02]

I just had my tc replaced. It was shifting like yours and just got worse and worse over about 8 months, kept getting stuck in gear. The shop said my tc was throwing bits of metal around and it damaged other parts. You should probably have it looked at now before it gets worse and the rebuild is more expensive.

I'm thinking of just leaving it sit for now. Next trip will be to the dealer unless I can drop it and replace it myself. I'm always up for a challenge and haven't F'd anything up in a while. :icon_lol:

Time for more research to see how tough a job this would be. Not alot of cash to throw at this thing right now.

 

[LibertyTC]

This is something obviously best done with a lift or hoist.
Still having it properly scanned to begin with, would be beneficial.
My guess is about 7 hours re & re & installing torque converter if ya know what you are doing.
Going to dealer may not be best solution IDK, but I am sure there are better valve bodies and torque converter options, including shift kit for your transmission.
I am hopeful other guys more familiar with the 45RFE may comment further.

 

[ltd02]

This is something obviously best done with a lift or hoist.
Still having it properly scanned to begin with, would be beneficial.
My guess is about 7 hours re & re & installing torque converter if ya know what you are doing.
Going to dealer may not be best solution IDK, but I am sure there are better valve bodies and torque converter options, including shift kit for your transmission.
I am sure other guys more familiar with the 45RFE may comment further.

A real scan seems like a must right now and if confirmed I'm thinking I may drop it and have a look. Might run it up on my four ramps and have a go at it. It is currently my DD but doesn't have to be. I can use one of my other toys for a while. There seems to be a few upgrades out there for the 545RFE and 45RFE. I may include some while doing this if I decide to. I've always had a desire to disassemble things. Sometimes I can even put them back together. I survived my HG swap last spring unscathed. :icon_lol:

 

[TwoBobsKJ]

There are no clutches in the torque converter - but the TC is connected to the trans input shaft which then connects to the clutch packs for each of the gears.

A trans-specific scanner will read the Clutch Value Index (CVI) for each of the clutch packs. Typically the CVI's will be at or slightly out of acceptable range before a code is set by the on-board computer. When the CVI's are out of spec the computer is looking for the speed of clutch packs to match the input shaft speed generated by the TC. If there is a mismatch the computer will try to get them to sync up - if it can't do so then there is the shudder. It could be a clutch pack or packs going bad (will be metal shavings in the filter or pan) or a vane is is coming apart in the TC.

Take your KJ to a good ****** shop and have them take it for a spin with the scanner hooked up - make sure they check the CVI's and show you the results. Will tell you if it's time for a rebuild or repair.

Keep us posted!

Bob