[altt225]

First off I would like to say thanks to everyone for posting such useful information. I have been lurking here for some time now and have finally decided to post a question/problem. Here it is:

I have recently experienced some vibrations coming from the truck. The vibrations usually occur above 15mph and start when I go over a bump (small or large). The vibration will stop after going over another bump. I jacked up one side of the front axle to check for ball joint play and fount them to be fairly solid. I also put a long prybar under the wheel to see if I could get any movement out of the ball joints and wheel bearing and found no excessive amounts of play (nothing I could see or feel, I didn't have a dial indicator handy). The wheel rotates freely as well. While poking around under the front end, I did notice the axle shaft/u-joint running from the main axle tube to the hub has a lot of play (+0.25in). Is this normal? Is this the vibration I am experiencing? By the way, I also checked the rear axle and it appears to be fine too.

The only modification I have made to the front end was replacing the OE locking hubs with Warn manual-locking hubs.

Thanks in advance for your input!

Andy T.

 

[altt225]

OK, so I guess no one has any ideas? Could someone please check their axles to see if they have the same amount of play, if any at all? I am trying to figure out if I have a major problem or not. /ubbthreads/images/graemlins/confused.gif

 

[Jimmy3336]

First off welcome to TDS. I had some problems with the front end the other day it turned out to be wheel bearings and axle needle bearings. I think if you'll check you'll find that your axle needle bearing is bad if the play u-joint is up and down. If its side to side I would guess it,s the outer seal at the nuckle. Good luck hope this helps

 

[The_Dude]

Play in your front u-joints couldn't cause any vibration if your hubs are locked out and your transfer case is in 2x4 mode.

 

[westpsd]

It is the needle bearings that run on the axle shaft. There is only about .002 clearance between the bearing and the shaft when new. I had the same thing happen to me. The needle bearings are replaceable without too much trouble and are cheap, however with that much play, you have damaged the axle shaft. A new shaft is about $120 from Ford (have them look up the outer axle shaft for an F550 which is the same shaft. If they look up one for a F250, it will say you have to buy the entire axle assembly which is like $400 each). I took mine to a machine shop and had it hard surfaced and machined and has been running for 30,000 miles with no problem. On our trucks, the bearing spins around the axle when in 2 wheel drive and turns with the axle when in 4X4. If you want to check, put it in 4 wheel drive and the vibration will be gone.

 

[klhansen]

I'll second what westpsd said.

You can get the spindle bearings for under $10 each at any parts store. The stub axle is most likely a Ford only part, but you might check with a driveline shop as an alternative.

Here's the part #'s for what you might need.

BEARING 550759 (4x4 front spindle bearing)
C6TZ-3123-A
B2110

Front axle Stub shaft only (F250-F550)(SHFT-FRONT AX YK)
4C3Z-3B387-AA

Also check the Ball Joint Installation Article and This Photo for a look at the spindle bearing.

Hope that helps

 

[altt225]

OK. Thanks everone for your suggestions! I will check them out shortly. In the mean time, does anyone know of a place where I can purchase a rebuilt axle as an alternative?

Oh, something else, where can I find a drawing showing the assembly of the front axle? Thanks again!