weird thump when stopping and going

[j_dixon07]

im getting a thump when i make a complete stop in my 04 f350.. almost is like you have a half full drum off water in your bed, its an extra little kick just as you make a coplete stop. it also has the same but backward effect when i start to go. dont no if it nothing or something i should be conserned with, just picked up the truck the other day so couldnt tel you if it just started happening.

[dslkraz]

Could just be a bad u joint but it could be pinion slap

[j_dixon07]

i checked the u joint befor i bought the truck, they all felt fine... not sure what pinion slap is, sounds major. can you clearify??

[TwinTur8os]

It might be pinion slap I have the same problem I have to wait till the weather cools down before I work on my truck. You have to drop the front drive shaft there is a nut i believe check the tq on that or it can be a bearing that needs to be replaced Im not sure I have not done mine yet.

[dslkraz]

Pinion slap is where either the bearings adjustment or the gears are wore out or broke and the pinion slaps the ring gear because there is too much play you can check it by dropping the driveshaft and rotating the yoke to see how much play there is between the pinion and ring gear