Re: 10 bolts and 39.5
Not to take one side or the other. A 10 bolt is "fairly strong", but if after 10+ years of use and abuse, things like bearings (carrier, pinion, spindel, hub/rotor), seem to wear. Metal fatique also plays a role in shafts and worn out u-joints. A D60 is stronger and will take more abuse and also more neglect (poor maintainence) before it grenades.
I'm not saying 10 bolts are the best axles in the world, but if you keep maintenance up, (i.e replace bearings once in a decade
, replace u-joints(yearly or more), and keep parts updated (wear causes increased tolerances, increased tolerances cause more leverage on parts and slack, more leverage and slack equals broken parts) a 10 bolt will last a long time under moderate abuse.
That being said, even a good 10 bolt is likely to brake with 38+ tires, a big-block, rocks, and a heavy foot. It also can survive fairly long with 39's, lighter foot, and smart driving, but a worn out one might not even last with 33's on the pavement. Again there are way too many variables. If you noticed on Trucks they put in an updated 10 bolt front. A lot of people, said "I can't believe they put a lousy 10 bolt in with that motor and tire combo". They also said it wouldn' last a day wheelin. First off, it wasn't your average 15 year old 10 bolt. It was a new housing with new parts with (I believe Moser hardened) shafts. That axle will take quite a pounding. Can it break....yes, is it as strong as a D60......no, will it be more than 85% of the people on this board need....yes. Will a rebuilt stock 10 bolt be more than enough for 85% of the people on this board (assuming proper maintenance)....yes.
If you are truly hardcore, I would say don't even bother putting a 10 bolt front in, but for most people on this board. A refreshed 10 bolt will last a long time.
If you don't believe me, look at the pictures in the member's section. I now have a Dodge (cringe) D60 up front, let me preface by saying we can't add weight to the front (that's cheating), so I put a heavier (weight wise) axle there (the D60 was much heavier than the 10 bolt to help with traction (notice how the rear squats, lifting the front up). I rebuilt the 10 bolt (with stock shafts), I put in new balljoints, spindle bearings, spicer u-joints, new ring and pinion with all new bearings and shims, seals, hubs, and front cover with bearing cap preloads, and a loc-rite locker. I abused the thing offroad as well as pulling the transfer sled (like the big-boys pull <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot>http://coloradok5.com/gallery/Leadfoot</a>. The one thing I always kept in mind was being easy on the go pedal when my tires were pointed any direction but straight forward, and never had a problem.
Again my $.02, take it for what it's worth.
P.S. 6,200 lbs with gear and two full tanks, and yes there was weight added (shhhhh)
There is a Right way, a Wrong way, and then there is My way. The latter is usually the most fun!
