Rear end shaking under acceleration
 

Hi all, I've noticed that when I start from a stop in first gear at a slow to moderate pace, sometimes the rear end will shake and sort of hop. The wheels don't hop, and I don't lose traction. It is more noticeable when I have the wheel turned, so I'm wondering if it has something to do with the differential. Anyone else notice this?

No

Im afraid That this does not occur for me

I notice this, yes, and can sometimes hear it as well.
See if any of this sounds like your issue:
http://www.ft86club.com/forums/showthread.php?t=45641

EDIT: Only on cold start and only for a turns.

Also noticed this and have wondered; can't reproduce it on a consistent basis...but it is more common then I would prefer.

Mines never shake, but makes a loud pop/thunk when I turn the wheel all the way and start moving from idle.

If a tire begins to slip at slow speeds you may get a sensation of wheel hop. That's the way Torsen diffs work. This happens more frequently in slow speed corners. The slower and tighter the corner the more you will notice this. Most of this effect occurs in first gear.

The effect can even trigger the flashing yellow light on the traction control when no traction control is required.

Try it with the nannies off? Just wondering if you're getting some wheel spin and the nannies are kicking in oddly leading to a hopping type of feel.

Bringing this thread back from the dead. I still get this all of the time, but only when the wheel is turned and I'm starting out from a stop. It's fairly violent though, and it feels like the rear diff is acting in a way it shouldn't. I will try to film it and set if I can get a noise. It is NOT simply the rear tires skipping, though it may be related, and it definitely reminds me of wheel hop.

I get this every day in the am when leaving our street first thing in the morning, but is not "violent"

It's your limited slip differential doing it's thing. How many miles do you have on the car?

35k miles.

Is there no way to change things so that instead of the shaking, it just spins tires (other than launching)? I wouldn't mind that...

Sounds like it's binding....aka my ford ranger fx4 has a LSD-clutch style though and without a friction modifier it will do the same thing you're describing, but in saying that we have a torsen(frs/brz) so it's not really related. My guess; it sounds like the fluid is too low or has gone bad! I would get them to change the diff fluid at the dealer and go from there but if it's still doing it then write down the conditions it's happening and get the tech to replicate it exactly as yor noticing it. That way you might have a better shot at getting it warranties should something be wrong mechanically. Good luck

If you havn't changed your fluid yet do so.

Mine does it too. It's the inside wheel that tries to turn too quick and looses traction a bit. Turn on a dirty street and you will hear the rocks slide instead of having the tires grip and jump on clean pavement. Find a buddy that has a car or a truck with a welded rear end. That is to the extreme.

I just changed the fluid in my diff motul 300. Never noticed it before but I noticed it now. I know the fluid level is correct also. Does it when I'm stop and slightly turn as soon as the clutch full disengages it will give a noticeable rumble. Nothing crazy though. Idk I hope it's ok lol. @Tcoat

As many others have said, works as designed. Should feel the clutch diff turning a corner in my brother's 911, total rumblefest. #becauseracecar

I concur. I can pretty much make it happen on command. Odds are it has always done it but you were paying more attention after changing the oil so are just noticing it now. Don't sweat it all is good.

It's fun when I goose it just enough to lock it and get the inside wheel to chirp a little. :thumbsup:

...because I'm still 12 on the inside.

The is a brief window in the spring where the roads are bare and dry yet still have the sand on them from the snow. Pretty much every turn can create that 'cuz I am also pretty much 12.

Hee hee... :clap:

Heh, I actually (finally) made it to 17 so I'm old enough to drive and chirp my rear tires.



Unfortunately I must be fooling myself though because I often forget to turn off the nannies and the wheels won't spin so it doesn't really make the noises that the OP was talking about.

Nannies take longer than that to process all the inputs and react. I bet it's real. :cheers: <--root beer for you. ;)

Ooh root beer... Yay! Mix it with a scoop of French vanilla ice cream and 2 shots of spiced rum and ya got a Big Boy Float :thanks: