So this started about 2-3 months ago, I thought it was tire related, but after putting new tires on the truck it's not. I'm pretty sure its the rear end, and it's horrible when making right hand turns, and will chatter until I have the wheel within half a revolution from straight.

It chatters way worst when I have the fifth wheell on the back as well.

I don't feel a chatter when driving straight line.

I was told it's most likely a bad cluth pack.

My question is short of rebuilding clutch packs, is there any way to make the rear end a one wheel wonder and save some money. I'm actually thinking about trading it, but wonder if they'd notice on a test drive, if I trade during the winter my odds of sliding this by are a little better with snow etc. on the ground and not dry pavement. I don't want to stick the next guy with it, but I really don't wanna dump more money in it if Im gonna trade either.

Truck is 2005 F 250 Crew Cab Diesel. 3.73 Locking Differential.

It has 86000 miles on it. I did drop the rear end fluid and changed it at 81000 miles, and added 3 bottles of locking differential additive.

This is actually my second problem with a rear end on a Super Duty, call it bad luck, but I had an 2002 which the rear end failed at 42000 miles (that's a different story though).

Thanks,

Chris

 

Crazy as it sounds, mine was shuddering.. Wouldn't say chattering yet but getting there. It was at about 30k, still in warranty so I took it to the ford house and they changed the fluid which fixed it. Only put about 10k on it since but so far it hasn't come back. Did it do it before the change or just after the change? Did the fluid look burnt at all?

 

Yes shuddering might be a better description. Its not constant. More like ......... ......... ........ ..... ... . Yes it was doing it before I changed fluid. That's why I changed the fluid. It's steadily getting worst.

 

When you say locking differential additive, do you mean friction modifier? I did it with my 02 at 100K and it got better until about 120K and it started coming back. Definitely worse when towing my 5th wheel too.

It sounds like its used up.

 

Yes friction modifier. Or slippy stuff so it will slip. I have 3 bottles of additive in it now. It calls for 2. Never got any better. I just can't believe that clutch packs should be used up at 86000 miles. Yes, it's definately more noticable when I have the 5ver on the back. We took off after eating a couple weeks ago, and the noise was scary for a couple seconds when turning out of the parking lot.

 

Mine was making a bad rubbing noise as it rotated, i took it into to get looked at because i was sure there were bearings that were shot- there definitely were and also the clutch pack was messed up. it was just the noise though, no shuttering or harsh vibrations.. might want to have it checked out

 

Did you use the correct friction modifier? There were two different ones when I had mine changed. I got stupid and went to one of those quick change oil places and had the oil changed. I told them I needed friction modifier added. Luckily I caught them before they put it in. It was some generic one size fits all crap. I went over to the Ford dealer and got the right stuff. They even told me there was a couple different types.
Just a thought.

 

The factory limited slips in these trucks are turds. Mine was shot well before 60K, and I don't (or at least didn't) tow anything on a regular basis until about 50K, then I bought a boat. If anyone is in the market, I recommend the tru-trac. No more additives, and works awesome.