So I've got a clunk when putting it in drive or reverse, and it seems to be coming from the rear drivers side tire. Or at least that side. Haven't had someone standing outside it yet to tell me if the other side is doing it. Any ideas as to what exactly this is. I can sometimes hear a slight clunk when driving really slow, but it's not as loud. Any ideas would be appreciated.

 

Check U joints?

 

+1 on u-joints - at least verify those first before going further.

 

What do you have? Year-Model-2wd-4wd

 

Ok, so here's were I'm at. First it's a 2004 FX4 SCREW. I've got about 7 months left of warranty so I took it into my local dealer. I left it there and got a call back 2 hours later. They had lubed up the yoke on the driveshaft and said it was good to go. Went and picked it up, got in, tested it just like I always do after getting warranty work done. No change. Same clunk. Walked back in, they took it back and put it on the hoist for another 2 hours. This time, they supposedly took apart my leaf springs and cleaned them cause they had some rocks and such in the them. Same thing, took the truck did the same thing. Now the mechanic is saying that it's temperature related. It's -20 celsius here right now. When I asked him why my friends 07 doesn't do it in -20, he had no answer for me. He says he's sure it's not the diff or the driveshaft. I'm no expert, but I've had two older vehicle's that at one time or another had a bit of a clunk, and the cold is not really a factor in this to my knowledge. One was a u-joint. The other was a worn out diff. Not sure what to do anymore. I've checked what I can, spare tire is tight, if read on here that some guys have that problem. So I'm kinda stumped.

 

I've got another quick question. I've been doing a lot of reading, and unless I'm misunderstanding people, we have a clutch pack in the rear end????? I'm no mechanic but I always thought there were only clutch packs in the tranny. If this is true, could this be a possible problem???

 

OK, so after some more reading, I find we have a clutch pack in the LS rear end. Never knew this, but now that I do, could this not be a very plausible explanation as to the symtoms that I'm having. If they are worn, I would think that they could cause all these symtoms. Clunking when shifting from drive to reverse and back again.(Obviously when the truck isn't moving, sitting in the driveway on even ground.)Any experts on these diff's I would love your opinion. Anyways, I think I'm going to take it back and question the "Shop Foreman" on this idea. Still any idea's welcome.

 

Hey, here's one more idea:
Check the tranny rear mount. i had a ranger with a "clunk", and 3 dealers could'nt figure it out. i finally got under the truck, put it in a place where i could rock it fwd and reverse ( with the motor off, truck in gear or in park for an automatic) and found the noise coming from the tranny mount! i removed the mount, found dirt and rocks in between the mount surface and cross member. cleaned it up, put some bearing grease on the cross member, re installed the mount and voila! no more clunk. I thought it was a u-joint from the beginning, or maybee the slip yoke, but the tranny mount was where it was at

 

Well I guess that's one more thing to try. It's going back in on Monday or Tuesday to get a bad alternator replaced on warranty and they were going to take a look at the "clunk" again. But that's definitely something I will check on my own.

 

Does it clunk when you are stopped and then take off (accelerate)?

 

Nope, it only clunks when shifting into gear. I've had the very occasional clunk after letting off coasting for a bit, and then getting back on the gas. But this is very rare. Probably an average of once a month or less.

 

Well I got my vehicle back last night, and surprise surprise, they didn't fix it. I got them to admit that it's not normal and that they basically just can't figure it out. But that's all they'll do. They say there's nothing they can do about it. Talk about poor service. So I guess I'll be going to a tranny/rear end shop to try and get it figured out.