Topic: Chevy rear spring

[DeMented Toys]

Poor planning or not, it is caused from the front diff swinging away from the t-case durring suspension droop. 

You are right that even though the rear diff moves forward it still needs a slight amount of play.  That is probably why the bearings in my t-case are really sloppy where the driveshaft attaches.  Luckily I have a fresh case to swap under there.  Whoever set the rear up like that with a fixed shaft must not have been a math major. 

[fordh8r]

The front driveshaft is the one that usually pulls apart or needs to be lengthened because when the front springs droop the diff moves toward the front away from the transfer case, extending the front driveshaft.  Opposite of the way the rear diff moved forward as it droops to keep the driveline length consistant. 

So the part that affects driveshaft length with the chevy spring swap is if your rear axle ends up farther to the rear, which is the case if you move the spring hangers 11" forward on an 83 frame.  As long as you have a driveshaft with the splines on the front that slides in and out then slightle longer distance between the two points(I measured about 1.5") won't matter too much because those kind of driveshafts will adjust out.  Hope that makes sense. 

So the moral of the story is just use a type driveshaft with the slip splines on one end and you probably won't even notice that the rear axle is sitting slightly behind the stock location.  In my case my driveshaft is either stuck together very tightly or is one solid piece so when I went to mock up everything I was like, what the shirt is going on here...   

I missed this last post.     True, with good planning a front D-shaft won't come apart. Part of that planning should include long slip D-shaft with more front travel since the front axle will effectively move away from the transfer case as you stated.  The rear doesn't or won't typically need as much slip for this reason.

[fordh8r]

Poor planning or not, it is caused from the front diff swinging away from the t-case durring suspension droop. 

You are right that even though the rear diff moves forward it still needs a slight amount of play.  That is probably why the bearings in my t-case are really sloppy where the driveshaft attaches.  Luckily I have a fresh case to swap under there.  Whoever set the rear up like that with a fixed shaft must not have been a math major. 

I'm no math major either but with enough time in doing this stuff your eyes open up to the less obvious things as you go as have mine.   

[Tallchevy]

In my case my driveshaft is stuck together

This sounds right.

[fordh8r]

Have you found out what was up with your D/shaft?    Did you fix it?  Just curious...

[DeMented Toys]

Yes, I had several so I took them apart at the u-joints and made one that works.  Build pics and info here http://board.marlincrawler.com/index.php?topic=39009.0