Strange Transmission Issue

So this is the second time I can recall this happening:

driving on highway, automatic is in 4th gear cruising around 60s-70s (slight incline and hence 4th gear), not heavy acceleration, just steady mid-pedal acceleration when BOOM it feels like the truck got hit from behind but no accident. it's as if the gear slipped and then engaged super hard, it happened so quickly i couldn't even make out if the truck had tried to downshift in this process...i would guess yes since after this it feels like a jolt of torque/acceleration.

no weird noises. this last happened about 13 hours into a 16 hour drive on mostly highway. I have the OV tune and Nitrogears 4.88

Has this happened to anyone? I'm not exactly sure what to do going forward as this isn't exactly a reproducible problem...

 

I would start by sending Mat a pm and see what he says.

 

What’s the rpms doing during the hit from behind?

 

This isn't you is it?

 

Oh my

 

How many miles on it? Ever have the transmission fluid level checked or transmission flushed? Assuming you changed the rear diff after first 1000 miles with the new gears? Does not sound like an OVTune issue - sounds like your tranny. If it was the gears it is likely they would have exploded in the rear pumpkin leaving you stranded. FWIT - I have about 25k miles on 4.88's and the tune. No issues like you describe. I have done a complete flush and fill (with fluid level check) on the tranny and changed the rear diff fluid at 40K miles. Also be sure to lube those U-joints at lease once a year.

 

about 80k miles. yes changed diff fluid after break in and did tranny fluid about 10-15k miles ago

 

honestly, it happens so quickly and unexpected that i can't say for certain, i think thay may jump for a second but obviously i let off the gas immediately when this happens. it's very strange, the closest thing i can describe it is like being rear-ended while going 60 mph

 

The bigger question is why were you in forth with 4.88s and OvTune on a mild hill....

 

It's the torque converter most likely. It's been a thing since day one.

 

...explain? is there a TSB on this?

 

Yes