AustinTaco

My truck is an 84 4runner, 4.88/detroit in rear, 35's, 5" of lift, with the 22r.

I am having a problem with the pinion nut becoming loose. Is this due to the setup of the gears? pinion angle? Here's the history of the problem:


When I bought the truck and drove it back to TX, the pinion nut started to become loose. At the time, I didn't know what the problem was, only that it started making a "rumbling noise" and a local mechanic, unbolted my driveshaft and tightened up the nut. The truck ceased to make the noise, and I made it to the next town and stopped to check the rear carrier. I found oil seeping out at a fast rate so I had a mechanic look at it and I was stuck there for two nights.
This mechanic thought the gears would be shot, but when he took everything off, he said the gears were good, but I needed new front and rear bearing, seal kit, and a crush sleeve. He put it all back together, and I made it back to town safely.
That was in the Summer, and I have driven the vehicle about 3000 miles since then, including one good wheeling trip with no problems. However, the other day, I was driving along and I hear "the rumbling" again and then I hear the driveshaft fall off and I coast into a parking lot to park and retrieve it.

It looks like the nut came completely off and the the driveshaft just slipped out of the front. Its sitting at the shop waiting to be repaired, but I am just looking ahead so that I don't keep having the same problem.

Thanks!

4Crawler

iTrader: (3)

They can loosen up with use, worse with an automatic locker in back and worse with a crush sleeve vs. a solid spacer. Could be due to improper bearing pre-load setup or not properly staking the nut after doing so. Good thing to check 1-2 times/year. Just grab the flange and give it a tug and feel for play (tranny in neutral). If play is found, try snugging up the nut, I used to need to do the one on my old Detroit rear diff. Unstake the nut, torque to 90 ft-lb and restake it. Mine finally bottomed out and stopped loosening after a few years and about 1/4 - 1/3 turn on the nut.

AustinTaco

Cool. That's probably the problem. I think I am going to use a solid spacer this time. Thanks Roger.

Mr Maraki

I drove by the shop on the way home today and saw your Taco there, it was good to meet you and shoot the breeze yesterday! Hope this is the answer to the problem, I'll probably see you around soon. Daniel

Mister Willie

I don't know if it's a possibility or not, but.. could you safety wire the nut?
http://marrc.nova.org/html_docs/rrs....ep.html#wiring

This site gives info on drilling holes for wire and how to do it. Any airport with a mechanic around should have some safety wire handy.