I've got a case of the 10 bolt blues. After 5 runs at the track running 11.5-12.0 times trapping at 118-123mph, I noticed a slight vibration from what I hoped was my driveshaft or a U joint. A third gear roll on at 70 mph on the highway heading home from the track finished off whatever was fatigued or cracked in the rear end. And I'm not talking like some grinding and I pulled over. It sounded like my driveshaft was trying to rip itself free from the confines of the driveshaft loop among other sounds. It was loud as hell! It had a major 'clank' 'clank' 'clank' as I was slowing down like whatever was hitting inside was pretty major. The driveshaft and U joints are fine, it's in the rear end itself. I'm running a 10 bolt with 28 spline OEM axles, Richmond 3.42's, Detroit Tru Trac, and a Trickflow aluminum stud girdle cover. I'm pulling the cover tonight, I will get pictures posted. Stay tuned.......

 

Subscribed lets find out.

 

sounds like a tooth broke or a spider gear broke

 

Those teeth are so small. No matter what you do to beef up the diff, the tiny teeth will never change.

Now the question is, do you repair the damage or spend a little more to upgrade to a better diff?

 

Looks like the pinion sheared half of it's teeth. You guys called it. I'm definitely upgrading. I'm leaning towards a 9". Moser bolt in housing, 31 spline axles, Detroit Tru Trac with 3.25 gears. I will transfer my LS1 rear discs to it. I want to go a little higher with the gearing, I was right at the rev limiter going through the traps.

 

pinion bearing clearance still good?-i had an F-150
break teeth off it's pinion after the pinion bearings got
a little loose and affected pinion/ring mesh...

 

Well, it looks like you can just put in a new R&P for now to get mobile again but an upgrade should be in your near future as the gears will probably fail again.

A few years ago, a fourth gen got pushed off the starting line. They pulled the diff cover in the pits and the pinion looked just like that.

 

I set up this set myself about two years ago, and I haven't had a peek inside since, except when I changed the oil after break in. It always had a slight gear whine while cruising which I contributed to the possibility of my pinion depth possibly being off a couple thousands plus or minus. Others with Richmond gears claimed they whine a little even when setup perfect. The mesh pattern was good, .012" backlash and I know I had the bearing preloads right. I will be upgrading right now as soon as I figure out what I'm going to go with. I'm trying to learn about my Ford 9" options right now. Looks like I will have a used 28 spline 3 series Tru Trac for sale in the near future. Anyone know if I can trust the stock aluminum driveshaft and U-joints? Or are they just a tad bit stronger than the rear I just broke?

 

I'd upgrade to an all-new, all-steel shaft with 1350 yokes and 3" x 0.083"-wall, at a minimum. If you see more power in your future, start with 0.095"-wall.

 

My driveshaft is only 3 x .083" and still seems to survive. I also have a front and rear loop just in case something fails.

The OEM aluminum shafts are weak. I don't know the limits of an aftermarket aluminum but steel is a better option.

 

did that to many times went with a moser 9" and a nitrous ready driveshaft from denny's in ny nice piece and if you get their nitous ready shaft if you twist the tube or break a weld they will give you another one free

 

After a bunch of investigation, I think I'm going to go with a Ford 9". The housing from Spohn, already setup with LCA relocation brackets, LS1 rear brakes (which I have on mine now)and rear swaybar mounts. It looks like if I skip the third member from spohn and get that from Summit I can save about $200. Looks like it will end up costing me around $2800 not including shipping, and I really don't have the money right now for that. So I almost bought a used 10 bolt today for $80 off Craigslist, but I'm pretty sure it's a 2.73 open diff judging by what car it was from. Then my tru trac and 28 spline axles wouldn't work. I have it back together for this event called Powercruise which is happening in July. I could buy a cheap mini spool and run the 2.73's but I would still have to mount my brakes to it or convert my lines back to the drums that are on it. Instead of all that screwing around, I think I'm just gonna buy a used set of 3.23 gears from ebay and throw them in my rear end for $60 plus the cost of that Ratech pinion depth tool for $25 and maybe a bearing or two. I'll just keep the slicks off of it till I get my 9 inch. And I'll probably do a new driveshaft too. Thanks for the info on the driveshafts guys.

 

Not that anyone cares, but a little update on the rear. When I pulled the diff out, the left side bearing cap bolts weren't even tight! Turns out they stretched when a piece of the tooth jammed between the gears. The left side carrier bearing race cracked too. In my moment of "slap it together quick it only has to last a month", I bought only one new bearing race and slapped the old bearing back in. Tossed the used oem 3.23 ebay gear set in and re-torqued the old stretched carrier bearing cap bolts. The used pinion still had a bearing pressed onto it so I just left it. Whatever shim it had under there, was what it was gonna be!

Well that was over a year ago and 5,000 hard miles (stuck with my rule of no slicks however) and the rear is happy as can be. In fact it is perfectly silent too. Whatever pinion shims were on it were a heck of a lot closer than the richmonds I setup myself the first time. I've got a Moser 9" sitting there waiting to go in over this winter. Can't wait to throw the drag radials back on next year and go for a new low et!

 

It's always fun to read a thread with what happened or is happening several months/years down the road.