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Discussion Starter #1
Car runs smoothly until up to about 75 to 80 mph. Then a vibration starts in the left front wheel. When I turn the wheel even slightly to the right at that speed, there is a sound, almost like a grinding sound....but nothing on the wheel is touching anything. A couple questions......could replacing the wheel hub nut correct this..or maybe it needs to be torqued more...is there any possibility this might be that the left wheel axle is not correctly clipped in on the transmission, or would that cause problems at all speeds ?

Another thing is I have an auto transmission.. Recently it has started to go into "hold' mode once in a while, with the hold light flashing when I am driving. It stays locked in 3rd gear until I bring the car to a stop. Then it goes away and all is normal again. Car runs fine either way, but it is kind of a surprise when it does this.
 

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I think I would check the torque on the axle nut.
If that doesn't work, I might suspect the wheel bearing.
Don't think any of those other things would cause or fix this.
 

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Jack the car off the ground enough to check if it has any play from top and bottom to left and right. I'm also suspecting a wheel hub of there's play.
 

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Discussion Starter #4
My tools before were a wrench and a 2 foot bar. I got a 5 foot bar, stood on it and jumped on it. I got the wheel hub nut to move and tighten about 1/4 to 3/8". The sound like a grinding noise at 80 mph when turning to the right went away. Some vibration is still present, only starts at 75 mph. Not really felt in the steering wheel. Up to that point, car is nice and tight and smooth. Inner and outer tie rods, control arm, sway bar links all pretty new.

I am not a big believer in using an impact wrench for these things. Books mention torque should be up to 200 for wheel hub nuts. I have a pretty good feeling for when nuts like engine mounts are at 70 torque. This wheel hub nut must now be at least 150. With the ability to stake the nut, that should be plenty.

I plan to replace the rear engine mount soon. Hopefully that will take care of this vibration. For a while I thought the brake dust shield could possibly be a cause, since it was starting to come loose. I cemented it back down and it didn't change anything. Last resort would be a new hub plus a new wheel bearing.

On a side note, I had a shop install 2 new wheel bearings not long ago. The result of that was the bearings made a terrible noise from the beginning. I think all they did was pound them in with a hammer, not a press. They said the 2 wheel bearings must have been bad.

Then I had a different shop install 2 new wheel bearings. One was fine, the other made a noise. I finally removed that hub, took it to a shop myself, and watched while they took out the old bearing and pressed the new one in. No noise after that. But this does happen to be the front driver wheel where the vibration is coming from.
 

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Discussion Starter #5
I got a spindle hub assembly off a 2001 626 and put it in this weekend. The vibration is still there starting about 75 mph.
Up to then everything is great. Next I will replace the rear motor mount, which I know is bad. If after that the vibration is still there, I may try replacing the axle and see what happens. This replacement spindle hub assembly does seem to have added some benefit, but hard to put into words. Maybe a little more solid feeling in the speed range 0 to 75 mph.
 

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Had the same issue. I thought the tires that I bought from 4wheelonline were defective or not properly balanced. Well, it turned out to be a bad ball joint.
 

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You try replacing the axle??? For the most part, if the bearings are seated straight, you can torque them to what ever, you’ll never crush the races of the bearings... better to be tight then to loose
 

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Discussion Starter #8
I got the new rear motor mount in. It did help the vibration, now it is very slight at 80 mph and above. The only thing left would be tire balancing, or possibly the shop that installed the axle did not get it clipped in correctly (a remote possibility ?) If I get in the mood I will take off the spindle assembly again and see if it is clipped in properly.

The rear motor mount helps a lot in other ways, especially when accelerating. The old one just had the rod in the middle completely by itself with all the rubber gone. When installing it, I thought I would go from underneath as the manuals suggest. I can't get the car very high, so could not undo the 3 bracket bolts right away. Thinking you have to still go from the top to get the 3 bolts that hold the motor mount to the firewall, I decided just to do everything from the top. I decided to replace the egr valve at the same time. This went smoothly for the most part, the intake manifold does not take much time to take off, so I don't know why a big deal is made about that. The problem came when comparing the new rear motor mount to the old one. It looks like the big brother of the old one, quite a bit larger. I had a hard time fitting it within the bracket, and also the center of it was further back than the old one, so the middle hole did not line up with the bracket hole. I had to modify the new rear motor mount by drilling some, and modify the bracket too. Eventually got it installed, now quite satisfied with way the car drives.
The motor mounts are a big improvement to get back to the "new car" feel. It is comparable to when new brake rotors are put in. That also gives a "new car" feel.
 
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