Try this with your 48RE

[MDietrich]

9 times out of 10 I can get 3rd gear torque converter lockup at 30 mph if I follow this sequence.



Start out in 2nd with overdrive off.



Accelerate until TC locks up in 2nd (around 28mph).



Let off and shift into drive.



Start accelerating slowly.



Usually I can get lock up at 30 mph and keep it.



As soon as I turn overdrive on TC unlocks to shift and relocks at 50mph.



Sometimes it will lockup at 30 without any input from me in drive with overdrive on. It still unlocks when it shifts to od, and relocks at 50.



Anyone else notice this phenomenon, or is mine just special (or screwed up )



I'm not complaining or feel that anything is wrong, just seeing if anyone else can do this.



(65500 on stock transmission with regular service)



MD

 

[CHegreberg]

Yes, I was in stop and go traffic a few weeks ago and It locked up at 30 and would let go at 25. I though there was somthing wrong too. I pasted on dieselram and found out that it was normal, undersertian situations to do that and not to worry. ( i'm not sure about all those conditions you had but I think the od was off )

 

[bmoeller]

The lock-up clutch locks in 3rd gear, as well as O/D.