How many of you have experienced the pinion gear loosening up in your third members?

Mine has loosened twice (supoposedly) and trashed my gear set after less than 30k miles. The gear shop says that this is a common thing, yet my stock 4.11's lasted 160k miles.

I don't drive my truck disprespectfully. I am cautious of wheel spin and even then I only have a 22re and 33" tires.

What gives?

 

I have broken 2 sets of 4:88 gears. Both sets had broken from the pinion nut backing off. I up graded to a V-6 Third. I was also told by two diffrent people that the Toyota crush sleeve is a whole lot stronger than after market sleeves. Or you could go to a solid spacer. My V-6 third has the spacer in it now and if I ever rebuild my 4 cylinder third it will have the spacer in it.


Greg

 

They will do that, especially when a crush sleeve is used in the gear install. I used to have to tighten my rear pinion flange every 6 months or so with my 5.29s. Just check the flange for play and if felt, pull the shaft, unstake the nut, crank it down to about 90 ft.lbs., restake the nut and put the shaft back on. If you catch it early and keep it nice and snug, it'll be fine. On my old diff, I ended up adding about 1/3 a turn on the nut over the years, as evidenced by the old stake marks. I now have a solid spacer in both diffs (set up by Marlin) and they have not loosened in nearly 6 years.

Here's a how-to I wrote up (includes the seal replacement, skip that part if it does not apply):

http://www.4crawler.com/4x4/CheapTri...eal/index.html

 

Would some red loctite help?

 

If the nut is staked properly, that should hold it in place. It is not that the nut backs off and causes the loosening (again assuming it is properly staked), it is that the pinion shaft gets loose in the bearings and that is what causes the problem. Not sure what causes the loosening, whether it is the crush sleeve crushing further or the bearings wearing in or just improper setup in the first place. But in any event, you need to tighten the nut further to take up the slack and make things tight again. The key is not making it too tight, that is why I use a torque wrench with a crush sleeve, to avoid over-crushing it and making things too tight.

 

Do all V6 thirds have a solid spacer? or in other words, do V^ thirds suffer from the pinionloosening as well?

Would it be in my best interest to get a Toyota Crush sleeve on the next third build?
Where can I find more information about the spacers you guys speak of?

Thanks

 

Don't know the cutover date, but likely the V6 3rds are all crush sleeves from the factory. One good writeup:
- http://www.4x4wire.com/toyota/tech/crush_sleeve/

I think the logic in the above writeup is basically correct, but does not explain why solid spacer pinions don't seem to loosen and crush sleeved ones do. My guess is that the crush sleeve can get crushed further, even by 0.001", and that would be enough to loosen the pinion shaft in the bearings. Once it gets a bit loose, things can bang around and further loosen the bearings.

Marlin Crawler sells the solid spacer kits and as noted on his page:
- http://www.marlincrawler.com/3rd_pickup.html

"Solid pinion spacers replace the factory crush sleeve. These spacers reduce the need to retighten pinion nuts and reduce R&P failure due to excess backlash."

I'm running Marlin's solid spacers in both my rear V6 and front high pinion (V6) diffs and have not had to mess with the pinion flange nuts, other than to replace a leaky seal in the rear. The other advantage of solid spacers is if you have to replace a seal or change out a flange is that it is hard to mess them up. Just crank the nut back down to where it was (lining up the old stake mark in the groove) and re-stake it.

 

Awesome thanks for the info.