Rear End Info Needed

[Jeffs70]

ok here is what I have a
71 C10 with Trailing arms in the rear and a 12 bolt limited slip rear end.
a 70 with Leaf Rear suspension and a 12 bolt posi rear end.

What I want is the 12 bolt posi in my Trailing arm suspension truck.

I read some things on this and I even asked my brother about doing a swap but that requires that the perches be swapped.

But my main question is are the rear ends the same length and shouldn't everything work properly other then one thing is the posi rear end does not have a place to bolt the pan hard bar. I will just make a bracket to work if possible.

[nightmare]

posi and limited slip are pretty much the same thing. i'd say if it isn't broke, no need to mess with it.

to answer your question though, they should be the same rear end.

[sneakysnake]

If the distance between the backing plates are the same, then no problem.
70' was a 6 lug and 71 was 5 lug and can be swapped, but on the older years the axles are 1-1/2 narrower.They make a panhard bar kit that hooks to the shock bracket and here is a link to the perches if you dont want to ruin the old axle.

http://www.stockcarproducts.com/trkarm1.htm

[sneakysnake]

So were all comparing apples to apples.


What types of Differentials are there?

Conventional or Open
Limited Slip
Automatic Locking
Manual Locking


http://www.drivetrain.com/parts_cata...ifference.html

[Longhorn Man]

posi is GM's name for limited slip. They ARE one and the same.

[fastwillie 696969]

tape measure

[Jeffs70]

ok I was wrong on this info. I checked into it more and had my brother over here. We have found the 71 C10 with Trailing arms in the rear and a 12 bolt is infact open type. and yes I took both rear ends out of both trucks and checked them out. It will be a pain in the butt to change the perches and Shock mounts from the leaf rear end to the other. but I will get it done.

[djgebert]

Why don't you just swap the carriers? The posi and the non posi are the same size. Just pull the axles and swap the center sections out. Its a little work, making sure they are spaced properly, but nothing near fabricating to make the other whole rear end fit. I have swapped them out in a couple of hours before when it needed done quickly.

[Jeffs70]

Originally Posted by djgebert

Why don't you just swap the carriers? The posi and the non posi are the same size. Just pull the axles and swap the center sections out. Its a little work, making sure they are spaced properly, but nothing near fabricating to make the other whole rear end fit. I have swapped them out in a couple of hours before when it needed done quickly.

I was concidering doing this. but never have attempted it before so was reading up on it now as we speak lol. so its not really that hard of a job?

[djgebert]

No, its not that hard at all. I am going to swap the 3.08's out of my truck with some 3.73's here in the next week or so. You just need to pay attention to the spacers on the sides of the carriers and make sure the teeth on the gears are lining up properly.

[Jeffs70]

Yeah it was actually very easy just takes the time to clean up.
I think it took me about 2 hours just to take one apart because i was being careful and making sure i wasnt going to mess it up and that was me backing off and standing there looking at it for a while lol.
but the second one came apart and went back together in about 15 minutes total.

[Jeffs70]

I want to thank you all for the info was very helpful

[Jeffs70]

any Idea what weight oil I should use in the posi rear end. or if anything special.

[djgebert]

They have a regular posi gear fluid. You can get it at a dealer or just ask at the auto parts store and they will know what it is.