oil to help with gear noise?

[black dawg]

The 9.5 14 bolt in our family car burb has been noisy for as long as I have had it. I have had it apart many times, messing with the pattern (used gears I know), and the last time I had it apart I was able to get the pattern to look pretty much ideal. It was very close to making no noise at all for about 10k miles, but now it is back to full volume plus some. I had it apart again, and all bearings are preloaded still, but the backlash has opened up quite a bit. I am assuming that this pos ring and pinion must be going away (it is on the magnet now).

I plan on building a 14ff for it, but waiting for the right deal.
Has anybody had any luck with different oil weights/additives to help with gear noise? This noise is about 45-50mph, and is very noisy, in a burb. It is driving me nuts to drive it the way it is.

 

[diesel4me]

You could try straight 140W gear oil if your in a warm climate--or 85W-140 with some Lucas or STP Gear Treatment...some guys used to buy "Motor-Medic" at the parts stores and added that to noisy manual tranny's and diffs to help quiet them..I tried it in my SM465 and found shifting dam near impossible once the temps dropped below 20 degrees until it warmed up!..you could even feel the truck wanting to move forward in neutral,the gear lube was so thick!..

The old used car dealer tricks like sawdust,banana peels and chassis grease dont work for long ,so I'd avoid those...I'd guess the Lucas Gear Treatment would be the easiest to find nowadays..

 

[79HeavyChevy]

X2 on the Lucas oil treatment.

Ran some in my np205 last time it was apart and seemed to quiet it down some.

 

[ktmoutfront]

If you never want to open it again, and are going to do the swap soon, banana peels.

Real quiet, but man does it ever smell bad when you open it.

Just kidding. I saw it a number of times at the wrecking yard. Cracked them open and close back up instantly.

 

[diesel4me]

One old van we had at the junkyard ,someone wanted to buy the rear axle,we suggested he'd best take the diff cover off to see if it was full of water or rusty before we wasted time and effort pulling it for him..

The entire diff was pumped FULL of chassis grease,with maybe a pint of 90W mixed in with it..it was rust colored and as much water as gear lube was in there too...the ring gear was gun metal blue when we wiped the grease and crud off it too...looked like it had been heated up with a torch!..

NEXT!..forget about selling that one!..

 

[ryoken]

sawdust....