DIY: Steering Shaft U-Joint regreasing
 

So, Google can't find much on this site about the steering u-joint, or issues related to it, so going to put this up.

If you begin to have 'lumpiness' in the steering, where the power steering seems to be harder /softer in cycles at 90 degree intervals of the steering wheel, it is probably your u-joint.

Another way to explain this is: If you are driving straight, say 25mph, and you can move the wheel about 10 degrees to either side fine, but farther than this starts dramatically increasing the difficulty of turning the wheel, peeking at 90 degrees of rotation, then getting dramatically easier until it's at 180 degrees of rotation from center, then peeking to hard again, etc...

...then one of your two u-joints in the steering shaft may be starting to bind due to lack of lubrication, probably the lower one. Mine started to do this, and it was driving me crazy because I wasn't getting a Power Steering light, cleaning / replacing / bypassing the connector wasn't solving it, etc...

Well, you have 2 u-joints in the steering shaft, both are incredibly easy to get to.

The upper one is above your feet as you are driving, within the column. Just get down next to the car, driver's door open, and look up at the bottom of the column. u-joint is right there. It is probably not the one that you may have issue with, as it's fairly protected from the elements. At 82,000 miles, mine was still cleanly greased.

The lower one is just inside of the left front wheel (or right, if you are JDM and have the steering on that side), just inside the framing, about where the axle meets the frame. Simply jack up the left front, remove the wheel, peer in. The shaft running diagonally forward and down is the steering shaft, and the u-join is a few inches up the shaft from the steering rack. This u-joint is exposed to the elements, road grime, etc..., and more likely to have grease contamination and lubrication problems.

Basically, the fix is to get the joint cleaned, the re-greased. For cleaners, just about any petroleum based cleaner should work fine. I used WD40, carb cleaner might be a shade better, but whatever you have on hand that you can spray should work.

Get it clean by hosing it down from various angles, turn the wheel as needed for the other sides. Get any particles and contamination out of there. You should feel the steering freeing up immediately.

I'd recommend several cycles of cleaning and letting it dry to make sure you get everything.

Once it is dry (so the very liquid cleaner doesn't thin out the grease), grab some standard automotive grease and get a bunch in there. I used probably a thimble full and my finger to get it on both sides of the joint, rotating the wheel 90 degrees periodically to get it from all angles. Then spin the steering wheel back and forth from lock to lock several times to get the grease all spread around. Repeat as needed until the steering feels smooth again, and no longer lumpy.

Put the wheel back on, lower the car, and away you go!



It was probably another one of those things from Mazda that they didn't think through quite enough, and probably should have put some sort of protection around it. Even if just a rubber boot or something, to keep contaminates out.

100% sure that the harsh new england winter this year just got various grime up there and it lost lubrication.

This came in handy today. Thanks!

Thanks, sounds just like my problem.

I just started noticing a notchiness in left turns and it sounds just like this may be the problem.

Thanks

Subscribed for future reference.

I should note that after I made this DIY, I discovered that my joint bearing was too far gone for this remedy to be a complete fix, just a temporary one, to the tune of about a day.

I ended up making a DIY for the u-joint replacement a week later here: https://www.rx8club.com/series-i-do-yourself-forum-73/diy-lower-steering-shaft-u-joint-replacement-217115/

Quite a bit easier than I expected to replace it, and $50 for the joint isn't bad.

Thanks for sharing this, RIWWP. I just had the same problem this past week. Gonna try my luck with the regreasing. Not looking forward to have someone fix the problem for real yet...

Check out my DIY for replacing the joint. Far easier than I'd expect. Certainly not worth paying someone else to do.

Thanks for this, spent a few hours going through the cars loom followed by plenty of head scratching and all I needed was to regrease the joint.

Keep in mind that regreasing it is only a temporary fix if it's bad enough to be felt. You will start feeling the problem again before all that long. Once a bearing fails (which is what happened) no amount of grease will make it spherical again, only mask the problem for a bit.