Ok I have been trying to find out what is going on with my truck and I cant seem to find anything on here that points to all the symptoms im having. I have a 05 xlt 4x4 with 5.4. For the last 5 months or so I have been noticing a slip or grinding noise when I go up a hill and it downshifts into I believe 3rd gear.It sounds like going over rumble strips on the road but only lasts a second.It also does it sometimes when I pull out from a stop.Also when I let off gas or brake to a stop it seems to shudder a bit.Maybe its my imagination since I keep hearing for the grinding sound,I dont know anymore.Its driving me nuts(er). It doesnt do it all the time either.It has only 65,000 miles on it and never towed. I know im due for a total tranny flush since it never had one. Could this be the whole problem? Iv been reading other stories that sound close to mine but they never mentioned about the noise when pulling out. Could it be the rearend? im totally lost on this one.Other then that problem it runs great.Shifts nice. Im the type of guy that loves to figure things out and fix them myself but im puzzeled! Any help would be greatly appreciated.Thanks!!

 

Now I just noticed that if I pull out from a stop and my wheels are straight it does not do it,But if I turn the wheel just a little and pull out I will hear the grinding sound,just for a split second.Now what could this be?? The other time it does it is when it downshifts while driving.Or if I get on it a little.Please help!!

 

I would check all the u joints carefully. Sounds like you might have one thats bad. Jack up a rear wheel, chock it, and put it in neutral. Then you can move the driveline freely by hand and check them.also check your front hubs for play. Jack up a front wheel and see if you can move it up and down, or side to side.

 

Thanks,I will do that maybe on friday when I have off.So I guess it doesnt sound like the tranny afterall then?