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difference between open float rear dif and regular dif?

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Old Nov 6, 2013 | 10:17 PM
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Default difference between open float rear dif and regular dif?

I was wondering what the difference between an open differential and a regular one? I've heard.people talk bout them but I don't know anything bout them.
Also, I was wondering I have a 1992 F150 4X4 with the 351 Windsor. I know it.has the 8.8 rear end. Is that an open differential or what is it?
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Old Nov 7, 2013 | 12:09 AM
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By open float I assume you mean a full float axle. That is a type of axle that you would find on a 3/4 ton truck or larger where all the weight on the wheel is supported by the axle housing on the spindle.

A 1/2 ton truck will typically have a semi floating axle where all the weight on the wheel is supported by the axle shaft which is what you have.



What I think you are really asking is if you have a open or a limited slip rear end. An open rear end means that power is transfered to only one rear wheel at a time. If you had the wheels up in the air and spun one tire forward, the other would spin backwards. This is done with a set of gear inside of a housing for the purpose to transfer power from one wheel to another when you make a corner. The inside wheel of the direction you are cornering needs to slow down as the other one speeds up because is has a greater distance to travel. When you loose traction in an open rear end, the wheel with the least resistance is the one getting power for example when you hit a patch of ice.

A limited slip rear end is just like a open, but instead has a pack of clutched inside that lock the rear wheel together in a straight line providing better traction and power transfered to both rear wheels. When you turn a corner, the clutched unlock and transfer power to one wheel to allow one to speed up and the other to slow down.

To find out if you have an open or an LS rear end, look at the door jamb sticker on the truck. You will find an axle code where its either a pair of numbers or a letter and a number. If for example you have axle code 18, thats a 3.08 gear ratio open. If its a H8, its a 3.08 LS.

Last edited by sylver91; Nov 7, 2013 at 08:58 AM.
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Old Nov 7, 2013 | 04:56 AM
  #3  
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Originally Posted by sylver91
By open float I assume you mean a full float axle. That is a type of axle that you would find on a 3/4 ton truck or larger where all the weight on the wheel is supported by the axle housing on the spindle.

A 1/2 ton truck will typically have a semi floating axle where all the weight on the wheel is supported by the axle shaft which is what you have.

What I think you are really asking is if you have a open or a limited slip rear end. An open rear end means that power is transfered to only one rear wheel at a time. If you had the wheels up in the air and spun one tire forward, the other would spin backwards. This is done with a set of gear inside of a housing for the purpose to transfer power from one wheel to another when you make a corner. The inside wheel of the direction you are cornering needs to slow down as the other one speeds up because is has a greater distance to travel. When you loose traction in an open rear end, the wheel with the least resistance is the one getting power for example when you hit a patch of ice.

A limited slip rear end is just like a open, but instead has a pack of clutched inside that lock the rear wheel together in a straight line providing better traction and power transfered to both rear wheels. When you turn a corner, the clutched unlock and transfer power to one wheel to allow one to speed up and the other to slow down.

To find out if you have an open or an LS rear end, look at the door jamb sticker on the truck. You will find an axle code where its either a pair of numbers or a letter and a number. If for example you have axle code 18, thats a 3.55 gear ratio open. If its a H8, its a 3.55 LS.
I think H9 is 3:55 LS not H8.

H8 is 3:08 LS I believe

Last edited by Jake1; Nov 7, 2013 at 04:58 AM.
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Old Nov 7, 2013 | 08:58 AM
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Originally Posted by Jake1
I think H9 is 3:55 LS not H8.

H8 is 3:08 LS I believe
Sorry you are right, got that backwards.
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Old Nov 7, 2013 | 10:52 AM
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What has 3/4 floating under them?
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Old Nov 7, 2013 | 04:30 PM
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Real old cars had 3/4 floating. Old Rolls Royce cars used to have them and other European cars but no domestic cars that I know of. Learned about them back in college and there wasn't a whole lot of info discussed about it.
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Old Nov 7, 2013 | 04:48 PM
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didn't know there was a 3/4, iv only heard semi and full lol.
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Old Nov 7, 2013 | 04:57 PM
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Lol thats cause they don't make them anymore since maybe the early 30's.
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Old Nov 7, 2013 | 05:38 PM
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Hahaha yup that would explain why I have not heard of them as well.
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