So I’ve read all the other posts on this topic, lots of good info but most threads are dead. My problem is the torque converter does not lock on the highway as it should around 55mph once the TRANSMISSION reaches 180*. I’ve tested the solenoids and wiring through the gray connector near the dipstick and all seemed Within the 11-15 ohm range and also tested when the temp is up and TC not locking, ohms we’re higher around 16-17. So I dropped the pan and installed all 3 new solenoids from rock auto this morning and still the same problem. Everything shifts fine and TC locks up just not when it’s a little warmer. So I’m afraid it may be just the wiring gone bad.

So to clarify my question is what else could it be causing the TC to not lock when hot? Bad wires? How do I go about replacing the wire? Also I know there are write ups on a diy TC lock up switch but would that switch make it lock when it it warm?

 

Are the fluid levels okay? I just found that mine was way overfilled which will cause the torque converter and trans to act up really bad. Also maybe check the brake switch. I’ve heard if it’s out of adjustment it will mess with the torque converter

 

Yes fluid is clear and red in the upper half of the ok range on the dipstick, and the brake switch works as when the TC is locking up, tapping the brakes will instantly unlock it. Just doesn’t lock up over 180* heat adds resistance and I was thinking it was for sure the solenoids but could the wires to the damn thing. The torque converter itself is also a brand new remanufactured part I recently installed so you may understand why I want to resolve this issue

 

anyone else have this problem , I would like to know the outcome

 

yes, several have had this problem recently

The only succesful resolution I read was was to clean the connector that is beside the the dipstick (they had code 0740 (I think)

that is not the issue with mine (still not resolved) iin my case the wire reads open and I suspect it is the wire internally

I will have another shot at it in the near future

 

Dumb question, How do you know when the TC is locking up or unlocking? can you readily feel it ?

 

I ran a push button modded aw-4, in lockup the rpms dropped approx 220-250, could vaguely feel it. That was 3:55's and 31" tyres. R

 

I can feel when my TC is locking up, it is like it just shifted into 4th gear.......and the rpms drop by quite a bit.

In normal acceleration, my XJ up shifts through the first 3 gears and then at app. 45mph it feels like it shift one more time with subsequent rpm drop....that is the TC locking up.
I don't notice it unlocking in normal driving.

I do notice when it when it is not locking up and is taking a crap load more rpms to do the same speeds as I am used to

So far, cleaning the contacts has worked for me for about 125 miles over the last 2 weeks. Don't drive the XJ as much since I got a new Z71 with the 3.0 Duramax!

 

Complete Tip 10 at www.cruiser54.com. Adjust the TV cable. Make sure you are using Dex/Merc ATF. Not the MOPAR ATF+4 stuff.

 

yes in my xj with 32” tires it’s very noticeable. Once up to speed with little load on the engine like flat ground rpms drop it almost sounds like it’s bogging out but can accelerate. With it locked I can do 70mph at around 2000 rpms I think but if it’s not locking going 70mph would be somethin like 3000 rpms and heat builds up. When I approach a hill it will lose speed til it needs to unlock and shift down around 45mph or if I let off the gas then o again, or just tap the brakes.

Think I may just install the TC lockup activation switch and hope that works.

https://www.google.com/amp/s/emerald...up-switch/amp/