wheels turning in park

[Redrig]

when i was putting my wheels back on the other night, as i was tightening the lugs the wheels spun and it was in park and the driveshaft didnt turn. is this normal? if so can you explain this so i can learn more about this.

 

[Crankcase]

Do you have an open rear end?

 

[ld50]

It`s normal, one wheel should spin in the opposite direction tho` Part of how the diff works.

It`s hard to explain, but in an open diff, you have the driveshaft coming into the housing and spinning the large ring gear. The ring gear has.. Okay I lost ya.

We`ll ask Jeeves!

-edit-
scroll down to crankcase`s link and click on it!!
then click "spinning at different speeds" on the right hand side of the page!
it`s great!
If you can picture what would take place when the engine is off and nothing is moving, you can see that if you had both tires off the ground and you spun one wheel by hand, the pinion gears would cause the other tire to spin in the oposite direction.

Also that animation can show why (click turn to see the pinions change movement), when you lose traction on one tire, all the power goes to the tire that is spinning.

There`s actually some good info there, thanks for making me look it up !

 

[Crankcase]

Doh....
"The page cannot be displayed"

 

[ld50]

Crankcase, your getting a little personal with this guy, ain`t ya?

 

[Crankcase]

This worked however:
http://auto.howstuffworks.com/differential.htm

 

[ld50]

Yeah! Bingo! then pick spinning at different speeds and check out that graphic!

It`s so easy to visualize when it`s all moving.

 

[Redrig]

i have a limited slip differential. but im still confused as to why they spin in park. i thought no matter what, the input pinion had to spin. which i thought they only way for that to happen is it be in nuetral. in park the wheels did go in opposite directions but in neutral they both went forward. sorry for being such a dumba!! on this subject.

 

[ld50]

I guess the limited slip would only change things when power is turning stuff for you. with both tires off the ground and spinning by hand, there really isn`t any forces involved so it would spin the other tire opposite like that.

My old mustang was the same with limited slip.

 

[Opera House]

What a great reason

to go out, change your differential fluid and look inside. I just had to change one of the rear seals yesterday and pulled my cover off. What is really amazing is how they hold the axle on with that little clip and the dowel.

 

[Robert]

Your limited slip is probably more slip than limited. After a while they wear out, but supposedly the Ford 8.8 LS last a long time though. In any event, the breakaway torque on a new 8.8 limited slip is only 30-35 ft/lbs. As it wears out the number goes down. You apparently put more torque on the tire than required to get it to break away.

 

[Redrig]

well that clears it up. thanks alot guys, good info.