Hi folks

If this is in the wrong section I'm sorry

I have a 2001 F150 Crew 5.7L 4X4 with LSD. Just bought it

After driving a while it gets the classic rear end chatter when turning. When cold no chatter. I know 1st step is to drain the pumpkin and refill adding friction modifier. Now I'm a former Jeep Jockey and beck in those days after a day wheeling and doing a lot of water crossings it was common to do up a drain and fill of both diffs. We would typically clean the gears with brake clean then fill. These were mostly open diffs and the rare lunchbox locker. Is there a problem with cleaning the 9.75LSD with brake clean? Thanks for any relpies

-Raybz

 

5.4? My truck is doing the same thing right now so I will be following this one. Just changed the diff fluid last summer with royal purple

 

Yeah a 5.4, I don't have my glasses on today

Did you clean everything or just do a juice swap?
Did you add Friction modifier?

 

Yea i cleaned it pretty good. The royal purple is suppose to have the additive in it but maybe i should consider adding some extra. Mines not real bad, just when i take sharp turns on pavement it will shudder a bit.