Wheel bearings getting loose too soon.

[dr.beat]

I did a search on wheel bearings and couldn't find the answer I needed. I know I read it here before. Anyway, I have a '94 Ranger 4X4 X-Cab, 6" Skyjacker lift Class II, 3" body lift. I'm running 33X12.50X15 tires on 15X10 steel rims. I had all four wheel bearings (Timken) replaced about 200 miles ago and now they're loose. Can someone tell me the procedure and what torque spec to tighten the outer nuts? This is also the second set of Timkens I've used in a year. The stock Ford wheel bearings seem to last longer. Does anyone have any opinion on this? Thanks for any help.

 

[Blur2u]

Have you been driving through a lot of water?

 

[Todd]

The outer nut needs be spun down to at least 250 ft/lb, the 150 ft/lb they say to do is just not enough when running a wide tire and rim combo.

 

[dr.beat]

Have you been driving through a lot of water?

Not in the last 3 years.

 

[Wicked_Sludge]

+1 to todds answer.

i'd also like to add that timkens are very good bearings and i doubt they are the source of the problem.

 

[4x4junkie]

IIRC, the Ford stuff is Timken also.

As said, put about 225-250 ft-lbs on the outer locknut (manual hubs).

The way I always do it:

Use a good quality lithium-base wheelbearing grease (DO NOT use any grease containing Moly though)

Tighten the inner bearing nut to 35 ft-lbs while spinning the rotor back & forth to seat the bearings.
Loosen it a half-turn, then retighten it to 15 INCH-lbs (or just hand-tight using the socket).
Tighten the outer nut to 250lbs.

 

[dr.beat]

Thanks much for the help.

 

[arrabil]

Use a good quality lithium-base wheelbearing grease (DO NOT use any grease containing Moly though)

Woah! Why no Moly? Does that explain the grease separation I found in the bearings when I did the Ranger today?

 

[4x4junkie]

Moly grease is designed for sliding (friction) surfaces (driveshaft slip-splines, CV joints, etc), it's not made for roller bearings.

As I understood it when reading a few articles and discussions on this, the moly somehow turns gritty and can cause microscopic pitting of the rollers (moly is actually a harder composition than the bearings themselves)

Edit:
I just went looking around again on this and came up with this
http://theoildrop.server101.com/forums/showflat.php?Number=209183&page=19

It seems there is actually some debate on this.
Reading through that, it would seem some greases present this problem, and others dont.
IMO, I would still say to avoid it anyway. The wheelbearings don't need a Moly EP grease to begin with, so why take a chance?

 

[dr.beat]

As said, put about 225-250 ft-lbs on the outer locknut (manual hubs).

What is the torque for automatic?

 

[4x4junkie]

What is the torque for automatic?

Automatic hubs have only one locknut, which is kept in place with a locking key.

It is only necessary to run it up to 35 ft-lbs, do the rotor spin, then back it off and retighten it to 15 inch-lbs. Then you stick the lock key in.

 

[dr.beat]

Thanks for all the 411, 4X4junkie.

 

[Natedog]

Automatic hubs have only one locknut, which is kept in place with a locking key.

It is only necessary to run it up to 35 ft-lbs, do the rotor spin, then back it off and retighten it to 15 inch-lbs. Then you stick the lock key in.

Haven't had my auto hubs apart yet, just got the truck. Can you adapt this setup to the manual hubs?

 

[4x4junkie]

Haven't had my auto hubs apart yet, just got the truck. Can you adapt this setup to the manual hubs?

I s'pose you could if you grind the nut way down (as it is, it won't fit in the hub).

I don't like the auto nuts though due to the very coarse wheelbearing adjustments available.