Okay guy's. I have an 05 screw 4x4 5.4 L (94k miles)and have posted this question before and the service tech's can't seem to find the cause.

When I am travelling, especially up an incline, my rear end "clunks" and sometimes does it repetatively until I let off the accellarator. It does not do this all the time. And of course when the mechanic test drove it it did not repeat as it doesn't always do this. The mechanic did say however that next time to take the truck out of overdrive the moment it starts clunking. Well when I do take it out of OD the clunking does stop even without letting off the gas. He is saying that now he feels confident that it's a torque converter.
I'm to the point I just want this fixed but I thought I would see if anyone has had similar problems or if you think it could be a TC.

Thanks for any help!!

 

I had a mechanic tell me the same thing on my truck(04 f150 4x4 scab 5.4). I took it to the tranny shop and they ran some diagnostics on it and found that it was the engine missing. They said that it can sometimes feel like a tranny issue. I replaced the spark plugs and the problem was gone. My truck had 118K on it when this happened. I see you're pushing 100K. Have you changed the plugs yet?

 

I'm guessing the mechanic thinks the TC is locking and unlocking while in 4th gear? Or maybe staying applied but slipping and grabbing? That would be a possibility except the TC is supposed to be in lockup in 3rd gear too. At least it is on my '06. I think there's something else going on.
I know, big help - sorry
The diagnostics approach is the way to go - don't just throw parts at it based on the technician's best guess.

 

Mine has a light one-time clunk between 2nd/3rd that seems to occur just as I come out of an uphill turn around 30mph and about to accelerate lightly. Took it in a couple of times and could never reproduce it (of course!) for the tech who sat next to me. He reflashed the PCM and it appears to have helped a bit, but it still happens on rare occasion. I think he mentioned the torque lockup being confused and was supposedly fixed by the reflash.

If drive up an uphill stretch with a light load, there's a bit of annoying gear hunting that still goes on, but shift points were much worse before I got a reflash. Running it with O/D off going up the incline helps.

I've got about 40K on my truck

 

Thanks for the replies.

Yes, I am going to have the plugs replaced this week at the dealership and they also said that the throttle body needs servicing/ cleaned so I may have that done as well and see if these two will help. Even though I have high mileage on an '05, I take very good care of my truck and go by the maintenance schedule to the T. But this is driving me crazy. My biggest fear is breaking down on the beach. I use my truck to surf fish and it ain't cheap to get towed off the beach.

Thanks again for the replies and keep them coming please.

 

The only other time something like this happened to me was in my old Toyota RWD. Accelerating up a hill felt like misfiring all the way until I got off the gas.

Got me scratching my head thinking I had ignition problems for the longest time until I discovered my driveshaft u-joint was worn thin. It was so worn that the joint would bind on itself and create a misfire sensation while it spun. It looked like it was on the verge of breaking into two pieces if I drove it like that for much longer!

 

Yea I had them check that out as well and according to them it all looked fine.

Thanks

 

That's IMPOSSIBLE! Toyotas NEVER break down!

 

Well I had the plugs changed and the throttle body serviced/ cleaned and the clunking has seemed to disappear. I hope these two things fixed the problem. I sure thought is was transmission related.

Fingers Crossed

 

05 screw any trouble with the plugs? any breakage or sticking in the heads? My 04 s/crew is at 43000 and i'm starting to worry about them.

 

Not that I'm aware off but the service tech. did tell me that could be a problem when I dropped my truck off.