So what are the Pros and Cons of rebuilding a rear end on the truck VS rebuilding a donor rear end on a bench?
I was considering getting a rear end from a pick and pull and rebuilding it with a lunchbox locker on the bench and then just swapping the whole rear end out one day. Thoughts experiences?

 

Working on it on the bench, you can stand up, and turn the housing so you are setting stuff DOWN into it. MUCH more comfortable working position. (unless you have a hoist?) Also, it's a lot less likely to drip stinky stuff on you. Downside is, you have to buy one...... If you can get one cheap, go for it.

 

Both have pros and cons. Definitely easier for a shadetree to bench set a spare assembly.

I have the Lockright in mine. Hadn't driven it in the rain in a good long while. Forgot how easy it is to mis-align with the lines on the road under throttle.

 

Maybe a true tack would be better in that situation ?

 

Wouldn't matter. Its a truck, so, unloaded, there just ain't a lotta traction to be had in the back. Even when it ISN'T raining.

 

I have no problems at all in the rain with my rear Spartan locker which is the same type of locker as the Lock Right.

 

So here's the thing.

When both rear tires are properly locked together (lock right or other positive engagement locker), the back end will ALWAYS kick out violently unless the front suspension is set up to not allow such. This is because you have 0% traction in the rear in either the forward or side-to-side directions. Front suspension then takes over to "steer" which way the tail end swings.

When both rear tires are clutch-locked together (most LSDs), both tires may break loose, but they may not necessarily be the same speed as the clutch is not a positive lockup method. The backend will not kick out as much since there is more than 0% traction. Again, front suspension has a role, but not as much.

When an open diff is in play, one tire spins while the other does not. The tire that does not spin keeps 100% traction, thus not allowing the back end to kick out, and it tracks perfectly straight.

This is why you frequently see guys holding the cars straight in the burnout box in amateur drag racing. This is also why it's much better to do a rolling burnout than a static burnout.

 

Very true , a unpowered wheel will track better in that situation for sure. it will more easily roll with the truck rather than break traction and skate in the direction of the skid.
This is one reason i personally feel locking differentials are not a big help on ice unless its on a 4wd.
i guess on the street, the key is not putting a lot of perpendicular force on the rear of the truck by using slow gentle acceleration.
but a lockable differential is definitely an advantage in wet road shoulder situation in the coastal southeast where wheels sink down into black wet sand/mud

 

The rear will only kick out if you give it enough gas to break traction, it works just fine in the snow if you drive sensibly.