65air_coupe

I've been thinking I need to do some upgrades on my driveline before I go to wider rims and tires with my 406 and have often heard of changing over to BB half shafts as a first step. What exactly is involved with that change?

And what becomes the next weakest link in the chain...or fuse as it were?

Nowhere Man

The biggest thing with BB half shafts were caps that were bolt in instead of the straps.

65air_coupe

Are they still a bolt in?

Mike Ward

You'd have to disassemble the diff to replace the yokes. The 'BB' shafts themselves are identical to 'SB' except for a bit of shot peeing at the end welds.

Not worth the effort.

Scott Marzahl

Just install Spicer solid u joints all around.

65air_coupe

So where would you start before things start breaking?

Scott Marzahl

If it's only a natural aspirated 406 I wouldn't worry about it. I beat the heck out of a stock drive train with a very healthy nitrous sprayed 383 for over 6 years without any issue.

427Hotrod

The first thing I've always seen break if it happens to hook up is the outer stub shafts. I've seen it happen on relatively mild 327's with BFG street radials. Replacing them with good aftermarket axles (Tom's or equivalent), while not quick and easy is a good plan.

But before doing that, I'd install solid Spicer U-joints.

The halfshafts hold up pretty well usually.


JIM

65air_coupe

Thanks Scott, that's encouraging although all the horror stories and pictures of damage inflicted by broken half-shafts still worries me.

Thanks Jim, is there any downside to solid U-joints?

Scott Marzahl

Nope, Spicer solids are the best out there.

65air_coupe

Thanks again, I'll put that on my list of upgrades prior to tire and wheel changes.

4 Speed Dave

I went with all Tom's parts. As stated before 30 spline spindles, new larger half shafts and inner 30 spline stub shafts with 30 spline spider gears and a 1350 joint Denny's driveshaft and an Autogear M22W 4 speed.

65air_coupe

Methinks you probably stress yours a touch more than I'm anticipating!

myred63

Very nice ! and may I ask what engine you are going to use for this?
rgds

DansYellow66

I believe that usually the damage from a loose half shaft results from a broken U-joint and not the half shaft itself. That is what obviously happened to the underside of my car before I bought it. However, I also found the half shaft on that side was twisted a number of degrees because the two yokes were no longer in 90 deg phase with each other. That and a few posts/pictures of twisted in two half shafts over the years have demonstrated this also happens from time to time.

Scott Marzahl

You can certainly buy stronger half shafts from a place like Dennys driveshaft, they carry Spicer as well.

4 Speed Dave

496 BBC that I made look like the 427 that the car came with.