Front grind with bumps and suspension play

[Slu66er]

OK. I'm new here so I'll start form the beginning. I bought this PSD about 3 months ago. It is a 2002 F350 7.3 4x4, as the title says it has a grind when I hit a bump and there is suspension play. Now I have been through every thread and spent almost $2000 on rebuilding the front end. Front wheel bearings, U-joints, Ball Joints, Steering Gear Box, All steering Tie Rod ends, Etc., Also has new 33" All terrains. and its still there, not as bad though so i did some more research and read that there could be play in the needle bearings that spin when not in 4x4. The, i guess it would be the outer axle stub, it goes from the U-Joint through the bearings and ends at the hubs. The outer axle stub gets wore down and the bearings don't seal up against it. Is there any way to check this out. I mean I don't want to ruin $100 worth of new outer axle seals to check. Any help would be appreciated.

Kevin.

[Slu66er]

No one has any ideas? This front end is becoming a money pit... I think if I took off the differential cover i would find $100 bills stuffed in there somewhere.

[whitelightning150]

i wish i could help but i have no clue seems like almost everything has been replaced. Bump

[banchee9655]

how old are your shocks?? I have a 99 f250 with 173,000 miles with the original shocks and their makin a sound like you explained. is it when you hit a bump, get on the brakes or turning? if it is its your shocks

[Slu66er]

OK, they do have original shocks but I don't understand how they could make a grinding noise. Next chance I get I'll remove them and take a spin and see if that makes a difference.

[Slu66er]

Also this is the mind blower. In 2x4 the axle does not rotate and the needle bearings in the hubs rotate causing the vibration as they oscillate around the needle bearings until they center themselves again. When you put it in 4x4 the shaft is rotating at the same speed as the needle bearings and therefore there is no play variance in speed. My issue occurs in 2x4 as well as 4x4, no difference at all.

[LHMissions]

I might be totally off the wall here - but can you explain the grind part a little more? Like does it happen do you notice when turning AND hitting a bump?

My reasoning is this: The '99 - '04's have front leaf springs. A 33" tire ranges from 11.5 - 12.5" wide. On a stock rim, a 33x12.5x16 tire - when hitting a bump - on a turn - will grind. Its the corner of the tread rubbing across the leaf springs. It could also happen with a slightly narrower tire - like a 11.5". So a 285, 295, or - for 33" tires, a 305 - could in effect, create a grinding noise, when hitting a bump, and turning at near lock.

I only say this from experience. I have a '03 - front leafs, stock rims, LT305/70R16 tires. When I hit a bump at tight turn - I "grind" on my front leafs. There is a little obvious wear spot on my front leafs. Then again - I have had 3 sets of 305's on my truck - so my wear spot has had the chance to mature a bit. Might not be as obvious right away.

Check it out - this circumstance and possibility would occure in both 2wd and 4wd, as you have mentioned. Here again, I could be totally wrong - but it could be it too. Good luck to you.

[Slu66er]

Nope it isn't the tire rubbing on the leaf springs. It mostly occurs while doing 65-70 mph. While going straight and hitting a slight bump and it only lasts as long as the suspension is in play, if that makes sence. It grinds as the suspension plays. I feel it in the floor board throught my feet.

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Last edited by Slu66er : 08-16-2009 at 09:34 PM.

[Slu66er]

Im going to try and make a video of the play in the stub shaft I pulled the hubs off and was checking the play and there is quite a bit of play, maybe 1/2" at the tip of the shaft. Almost feels like it doesnt ride on the needle bearings at all. Ill try and put a video on youtube, and ill post a link in a bit.

[Slu66er]

YouTube - Outer Stub Play

K here you can see the shafts moving. At 16 seconds I switched to the other side.