My truck has been in my possesion for one year now. When I first got it, in April last year, I didn't notice anything abnormal going on. But, maybe a month or two afterwards, it started (what seems like to me) slipping at highway speeds and also, but very rarely, with OD off.<br><br>Then winter came and the problem just seemed to magically heal itself. I was relieved. Hasn't happened since probably last October/November-ish.<br><br>Now the weather is heating up again and my problem is back. I went 8 miles down the road going 60mph and the tach was jumping 200 rpms quite often.<br><br>Does this make any sense? And does it point to any specific problem? Because I'm not completely sure that my tranny is slipping... thats just my theory.

 

doomgaze<br>It sounds as if the lock up may be disengaging/engaging. Several things can cause this to happen: the TPS, the sensor in the tranny line, a faulty pickup in the speedo, some loose wires, or low or overfilled fluid in the tranny.<br>Of course, there could be more serious issues.<br><br>I would start with checking the fluid for over-under fill; check the tranny cooler, wiggle the wires on the computer, spray clean the TPS with contact cleaner...others will have more suggestions.<br>george