So a little background on my truck it is a 2001 xlt 4x4 with the 5.4 and 162,000 on the original motor and tranny. It has a 6 inch suspension lift and 35 inch tires and an aftermarket exhaust besides that no aftermarket parts. I bought the truck December 31st and up till the past month or so it has ran beautifully.

about a month ago on my way home from work i was driving and after I made a turn I hit the gas and it revved up for about a second then hit right into gear it worried me a little but it didn't feel too abnormal and went right back to normal just the one hiccup. Fast forward two weeks later it did the same thing again a little more worried still didn't feel like anything was catostrohically wrong. Then about a week later same thing same exact spot on the way home from work at this point I was just annoyed because it would do it once and drive great for a week or two. Then yesterday it does it again at the same exact spot!!! Always on the way home after about 20 min of driving this time I hear a little noise doesn't sound like anything breaking almost like a rumble then a whine this was the first time it made a sound it did it for maybe 10 sec this time I drove it got it into first gear fine and cycled though the gears it felt perfectly fine I parked it for about 4-5 hours then drove it for 30 min last night and it was fine. This morning I drove it 20 min to work no issues. The only correlation I can think of being in Arizona is it didn't start doing this till the weather warmed up in the past month and it seems like it only does it the one time on days that are 90+ degrees after driving around town stop and go for 20 min in the heat of the day. So am I screwed is this thing gonna go or could it be a clogged filter and dirty oil issue or a trans cooler blockage? It doesn't slip or shift hard it's just almost like a quick rev and then it catches gear and pulls out of it?
Thanks any advice would be appreciated

 

have there been any leaks from the trans to drop the fluid level? is the trans fluid low maybe? and what trans do you have?

 

It has the 4r70w no leaks I checked the fluid level while after driving while the engine was running it was full didn't look too dirty or smell burnt at al

 

what this sounds like is your fluid is low, due to turning
maybe someone will chime in here to further help

 

Yeah that's what I thought initially but when I checked it it is at the full line the only thing I can think of is maybe it's not reading correctly because of the way it sits with the lift

 

There is a dipstick for the trans fluid, -passenger side in the engine compartment. Check it.

NM- You replied before I finished mine...multi tasking lol.

 

Is it a healthy pink color ? Did you check it correctly ? The best, most accurate way is after at least 10 miles, 20 is better. Without shutting the vehicle off, place in park then go through the gears pausing in each until you feel engagement. Do this all the way down to 1rst then back up to park. THEN check it while it's still running.

 

yes it was after my 35 min drive home from work I parked it shifted through the gears then Left it running pulled the stick and it read full and was pink not murky or overly dark and it didn't smell burnt

 

Well, your not getting and DTC's right ? I'd try a modifier additive, since it's your clutches that are slipping. Perhaps a trans tune or Lucas additive. Helps the clutches engage. Really have nothing to loose. Your running 35's on factory gears no doubt, that's a lot excess stress your putting on the trans. When it slips are you going in a straight line, no turning ? If it slips while turning it's the clutch pacs in the rear end. The only other cure is to add a shift kit. A shift kit and Amsoil fluid saved my trans when it began to slip. That was over 100,000 miles ago for my trans. I didn't have many choices, either a shift kit or rebuild the trans. The shift kit worked for me.

 

No dtc's and yeah it's never while turning always after and never on the freeway always going about 5 mph after driving in the heat for 30 min or so and it only has happened about once every week and a half too two weeks. Thanks for the advice man I'll look into the shift kit and additive