bosman20

I have a 1983 pickup 4x4 SR5 manual. I was driving home from the shop, where I had just did an oil change on transmission and engine as well as rotated the tires. I am about 4 side roads from my home on the main highway when my truck just locks up, and starts fish tailing out of control, all I hear is the rear tire squealing on the wet pavement. I end up coming to a stop in the middle of the highway perpendicular to road blocking both lanes of traffic conveniently but better then ditch or oncoming traffic. I could not get the truck to move. Engine was running fine. I tried 2x4 and 4x4 hi and low + lockers, truck would not budge. I could feel the truck torque up as the clutch started to grab. I ended up directing traffic both directions, of course in the rain, until I had the truck pulled up onto a flat bed.
I figured the rear diff was the problem. I wasn’t that upset because I had an Elocker, studs, gaskets and Toyota wiring harness sitting back at the shop but no time to do the swap. I guess this was the time to do it, other than its -5C out and dropping, in a unheated shop. The swap went well other than a few unrelated problems with rusty brake lines breaking, and broken off bleeder screws on both rear brake cylinders. I thought I was all done, just had to bolt the rear drive shaft to the new elocker flange and I could be back on the road at least. But not so, I noticed that he flanges seated together nicely but would not bolt up. The bolt spacing on the existing drive shaft is 55mm x 65mm that I want to reuse(see pic) and the elocker drive flange was 60mm x 60mm (see pic).
My questions are :
1 - Can I Just undo the yellow zinc plated pinion nut (see pics with”? + arrow”) want swap the drive flanges one for one?
2 - What would the torque value on the pinion nut?
3 - Is there and adverse side effect to loosing off the pinion nut? Does it affect anything also inside the diff once the nut is loosened?
4 - Anyone know where to get the matting electrical connector for the stock elocker harness (see pic with arrow)

http://1drv.ms/1xMF1hM

g3bill2

stock torque for the nut is 123 to 151 lbs. low end is good enough i think.

If your not just throwing it in there? I'd check preload to 7.8 to 11.3 INCH lbs. I set my ring & pinion lash to .007 but ended up with .005, I wouldn't go tighter than that and check throughout the full rotation of ring gear.
I ended up with a lash of .005 because my bearing race was spinning on pinion shaft so used locktite 620 to bond it to shaft but it sets real fast. As quick as i was, getting all the shims and such on buy the time I got the torque right it was setting up and couldn't pull it in any farther, good enough and didn't have to buy a new R&P set. The 620 is removable with heat and a press.

Pics to add some eye candy

Not needing to be perfect I saved some $ by replacing ring gear bearing races but kept the bearing rollers as looked good plus didn't have to pull or press bearing except for pinion big bearing.

TeeDubya

You probably have it sorted out by now. But there's no need to swap the flange. Just put the yoke on the flange and rotate it so the holes on the yoke are about halfway between the holes on the flange and redrill the holes in the flange to match your yoke. I had the same problem when I swapped the old 3.90 diffs out of my 81for later 4.10. I was racking my brain trying to figure out how to make it work, then I mentioned it to a friend, who is not a Toyota guy, he thought about it for about 2 mins and said "just redrill it." My 81 has been running on it for a few years now.

moroza

So how did the old diff fail?

Your options are:
1. Drill the diff flange to accept the driveshaft's pattern (it may be obvious, but you shouldn't drill the driveshaft flange, because it has a lot less material). I just did this for my new front diff, which came out of an IFS rear axle that I put an e-locker in. The e-locker and 86-95 diff have the same pattern.
2. Find a later driveshaft yoke and swap it onto your existing driveshaft. I believe this was done on mine, but it's possible that the U-joints are different and you'd need to cut, weld, and balance the center section of the driveshaft.
3. Swap the diff flange. The problem is that to do it correctly, you'd need to measure the preload and replace the locking nut. Then you might as well replace the pinion bearings while you're at it. The benefit is a half-rebuilt diff.

I was advised that if the bearings and wear patterns check out, to just tighten up the backlash with a couple of notches on the adjuster ring and throw it in. I did this to both my e-locker and the new front diff. I'm about to do a 500-mile diff breakin oil change, so we'll see how well that's worked out! Did you do the same?

ZUK

iTrader: (1)

Hi bosman-
Like Teedubya says, Best to clamp the old DS in place and re-drill the 4 holes. I would not recommend swapping your old flange in place of the e-locker flange....gets kinda messy to make sure you have the correct pinion bearing preload.
Re-drilling is much easier with a new bit. I believe the 83 is the smaller pattern with the smaller 8mm bolts