4th to 5th gear 18 68rfe

[Rigwelder18]

So I got my transmission rebuilt about 3 months ago. Ever since I got it back it does some weird stuff going from 4th to 5th. If I’m very light on the throttle or wot it doesn’t do it. But if I go medium throttle when it shifts from 4th to 5th it’s almost like it’s shifting then about a second or two after the tc is locking and almost like it’s a shift flare but only does it in those gears. Added a file of what was done.

 

[sag2]

The RFE feels like it has a shift flare on most gears. It isn't actually slipping, it is the converter unlocking, making the shift, then the converter locks again. If you do not have a gear ratio error fault the clutch/clutches is not slipping.

 

[BigPapa]

How many miles on the truck and what’s it used for? I have to ask, four year old truck and the transmission’s been rebuilt three times? They’re charging you $8,400 for a rebuild?

 

[Rigwelder18]

Truck has 117,000. And it’s used for a rig welding truck and I also pull an Rv with it a good bit. And yes that was for the last rebuild. And the first time was just clutch’s and the second time another guy screwed me over. Said he was putting in all hd parts and put it all back to stock.

 

[Ozymandias]

Usually you should be on your first transmission. Something is pretty wrong with your truck if it needs transmission work every 30K Miles. For now it seems like the shops don't know their business with all that aftermarket stuff they put in, on a stock truck also stock parts work just fine, no need for upgrades there.
I'd stop spend any money on that transmission and get a whole replacement from a reputable company.

 

[Rigwelder18]

It’s deleted and tuned also. I run it on 110hp tune. And the first rebuild was my fault. But the second one I got screwed on. Snapped the input shaft on the way home from Wyoming pulling an Rv. The people that built it this time was highly recommended in that area. Everything is fine in it besides the weird shift to 5th. And this last time they put it in a new case and everything. Everything in the transmission is new.