20 replies to this topic

[pods8]

I think I'm getting excess vibrations/play in my drive line. When doing 75mph and such at times my four wheel drive shift leaver (on the floor) will rock around a good couple inches which seems excessive. Counsel cup holders will also bounce around too. This is on flat expressway so its not the road transferring things up. Nothing notable happened to cause this and I'm just noticing it since I'm actually getting out in areas of WA where one can travel at such speeds (previous trips had been in 60mph zones for the most part). A quick inspection underneath doesn't show any obviously worn u joints or a freshly thrown drive shaft weight, etc. Any thoughts on what to check more in depth and how to do so in a driveway setting if possible?

New potential for a bigger trip this summer is coming around and I need to flush out as many gremlins as possible...

[pvstoy]

A quick inspection underneath doesn't show any obviously worn u joints or a freshly thrown drive shaft weight, etc.

You can't tell by looking at U-joints. Un weight the rear so the wheels will spin free. At both ends of the driveshaft see if the u-joints are loose or very tight. If you have exxesive play then replace them. Too tight means that they can be dried out and causing binding. If you have grease fittings get some in there. If not take the drive shaft off and have the U-joints replaced and then balanced.

[pvstoy]

Have you tried putting it in netural?

Does it feel like tires that are causing the vibration?

Hard to judge from here without being there.

[pods8]

You can't tell by looking at U-joints. Un weight the rear so the wheels will spin free. At both ends of the driveshaft see if the u-joints are loose or very tight. If you have exxesive play then replace them. Too tight means that they can be dried out and causing binding. If you have grease fittings get some in there. If not take the drive shaft off and have the U-joints replaced and then balanced.

All I've done so far was the try and shake the u-joints looking for gross wear. I currently still have the stock sealed type u joints so no grease fittings.

I have no issue on replacing the joints if others are confirming they or the drive shaft could be the likely culprit but I'd like to make sure I'm not over looking something like a mount or such wearing out (not really sure how the check those other than visually look for structural compromise or maybe leverage on them with a crow bar to check how much they move??).

Have you tried putting it in netural?

Does it feel like tires that are causing the vibration?

Hard to judge from here without being there.

Haven't tried putting it in neutral.

If you ask me it tends to feel like its more so in the drive line because it feels like its emanating from there into the counsel and such as opposed to the tires shaking everything and thus rattling the shifter as well. Also the steering wheel and steering doesn't really feel affected.

[EdoHart]

After checking U-joints and drive shaft balance, I would look at engine and/or transmission mounts. Then the pin holding the axle in place on the leaf spring.

Your signature doesn't include a lift, but if you have one, that can exacerbate some problems.

[pvstoy]

If you do the U-Joints yourself....mark everything how it came apart and make sure the phasing is correct for the front - rear U-Joints.

[pods8]

After checking U-joints and drive shaft balance, I would look at engine and/or transmission mounts. Then the pin holding the axle in place on the leaf spring.

Your signature doesn't include a lift, but if you have one, that can exacerbate some problems.

I'm still unsure how to really inspect the engine/trans mounts other than visually looking for tears and maybe applying some force against them with a crow bar. That sound legit or anyone have other directions?

No lift.

If you do the U-Joints yourself....mark everything how it came apart and make sure the phasing is correct for the front - rear U-Joints.

I'm planning to call the drive shaft place and see what it'd cost to have them pull the shaft for checking the balance and then installing fresh joints. If its under $100 labor I'll likely just have it done, otherwise I'd likely do it.

However I'm not sure what you mean by the phasing? I'm generally a self taught grease monkey and in the past I've just removed u joints and swapped the new one in place...

[EdoHart]

I'm self taught too, so take caution in whatever I say.

I think the way you describe checking the mounts sounds right. I doubt that is where the vibration is coming from, but I was thinking about things that might change your drive line angles.

By phasing, I think Patrick means how the mounting tabs for the U-joints line up at either end of the drive shaft relative to each other. If you don't remove the slip yoke from the drive shaft, I don't see how you would get it out of phase.

http://www.custompis.../ts_ujoints.htm explains it a lot better than I can.

[pvstoy]

Thanks Ed, That is what I’m talking about for “Phasing” Just follow the bottom of the link that was provided. I all ways make reference marks when things come off.

Most front drive shafts are not balanced very well. What I have done in the past is pull the rear shaft and go for a drive in four wheel drive high (front wheel only) and see if the vibration is still there. But if you have an output shaft that there is a slip into the transfer case then by pulling it you will have oil coming out.

Motor and transmission mounts you can take a floor jack and jack up on the engine or trans and see if the rubber is separated. Careful on punching holes or warping the pans and causing leaks or other problems.

Wish I was there to diagnose it with you.

[Barko1]

My F250 was out of phase but it was caught when I had a mechanic give it a good going over so it happens.

I'm self taught too, so take caution in whatever I say.

I think the way you describe checking the mounts sounds right. I doubt that is where the vibration is coming from, but I was thinking about things that might change your drive line angles.

By phasing, I think Patrick means how the mounting tabs for the U-joints line up at either end of the drive shaft relative to each other. If you don't remove the slip yoke from the drive shaft, I don't see how you would get it out of phase.

http://www.custompis.../ts_ujoints.htm explains it a lot better than I can.