Bad center support bearing?

[Jimmy9190]

This is about the 2001 Dakota in my signature. 2 wheel drive. It has 3 u-joints and a center support bearing on the drive shaft. Over the last few days I replaced all 3 u-joints. I used sealed Brute Force brand u-joints from AAP. I got it all back together very easily, no problems at all really with the installation of the u-joints or reinstalling the drive shaft. The u-joints and trunnion pieces all spin very smoothly. I went for a test drive and did not even make it out of my neighborhood. The truck has a bad vibration from the floor area as soon as I hit 30 mph. If I put it in neutral the vibration is still there, and I feel it in the gear shift knob too. When I hit the brake and slow down the vibration stops.

I did mark the relationship of the driveshaft to the transmission and the differntial before I removed it. I drew a line all the way down the center of the bottom of it and I reinstalled it in exactly the same orientation as it was to begin with.

I did not replace the center support bearing when I did the u-joints. The rubber surrounding it was old but still looked to be in good shape except for the section above the bearing. That part had separated and I could not tell if it was made that way or it had ripped apart. I believe the center support bearing may be bad. If anyone here can confirm that or has more info I would really appreciate the help.

Thanks.

 

[Donald]

From your description I would replace it whether its bad or not. It sounds like its not in great shape. How much?

 

[Jimmy9190]

I can get one at AAP for about $25.00. Problem is they don't rent the bearing splitter to remove the original one. I don't know if the problem really is the center support anyway, usually when that goes bad you get vibrations when accelerating from a stop. I had no problems like that before I started this u-joint job. I replaced the u-joints trying to cure a vibration at 65-70 mph. One u-joint had slung grease up onto the bottom of the truck bed so I replaced all 3 as a preventative measure.

I think there must be some problem or error on my part with the u-joints. The only thing I can think of is the u-joint in the middle. When I installed it in the yoke of the rear half of the drive shaft, it was real stiff. The other 2 joints moved and spun very easily, smooth as glass but the center one did not move easily by hand like the others. It was stiff even without the front half of the driveshaft on it. I removed it and found 2 needle bearings that had fallen so I put them back in place and greased it and reinstalled it. It moved easier after that but still not as smooth as the other 2 u-joints.

I have now gone back and re-rented the u-joint installation tool from AAP and picked up another u-joint. I am going to replace the one in the middle. It is the only thing I can think of that is out of the ordinary about this problem. The store manager at my local AAP said she will refund me the price on the other u-joint, no questions asked.

If anyone has any ideas on this I am all ears. Do the 3 u-joints all need to be positioned in the same direction when they are installed on the drive shaft?

Thanks very much for any help on this.

 

[mechtech2]

If U joints are not properly installed, they will have excessive wear and vibration.
I grease the insides of the yokes, and install them. Then, whack around the sides of the yoke with a hammer to seat them - it works.
Sometimes, a needle bearing can become lodged at the end of the cap, and cause grief [if the U joint was moved/opened before assembly].
Make sure your input angle and out put angle are the same, when loaded on the ground. A protractor helps.

 

[mattd]

sounds like you did not seat the joints. They should flop around easily, each direction.

 

[yonyon]

Each u-joint must move freely on both axes freely. You've got one that doesn't. This is probably due to one tiny little roller being out of place, but there's also a chance you bent a yolk. Assuming you've got a roller out of place, just replace that joint and be done with it.

You got 2 out of 3 of them right the first time. Now that you've got a little experience with it you should be just fine getting 1 out of 1 without issue. If in doubt, take it back apart.

The one u-joint that's already ruined gives you plenty of spare parts in the unlikely event it doesn't go right the second time around. Worst case, just buying one joint you have 4 opportunities to try redoing this. I expect that one redo will be enough.

 

[Jimmy9190]

Thanks for the replies. I fixed it. I believe I had the yoke at the differential installed wrong, it was 90 degrees off where it should have been mounted. I don't know how I missed that with all the reference marks I made, but I did miss it just the same. There is no excess movement or play in the center support bearing so I left it as is. I have no way to R&R it anyway but it seems to still be in good shape.

I also bought another u-joint at AAP and swapped out the middle one that was not moving freely. I am pretty sure there were needle bearings out of place in it but there was so much grease in the caps I could not tell. The new one spins much easier and AAP gave me a refund on the bad one. I also used the tool I rented and re-seated a few of the bearing caps. They were not quite seated all the way in and the retainer clips needed to be re-positioned in the grooves. I don't know if that would cause the vibration problem.

I believe I made a mistake by completely tightening the two bolts that hold the support bearing bracket in place. Last night when I reinstalled the driveshaft I tightened those bolts all the way and then tightened the bolts on the yoke at the differential. That may have caused the driveshaft to be slightly out of line, and maybe that caused the vibration. Today I just snugged the support bearing bolts down and then bolted the diff yoke in place, paid more attention to how the driveshaft was lined up and went back and tightened the support bearing bolts.

I have never replaced any u-joints before and I thought it would be fairly straightforward from what I read in my service manuals and online articles. I guess it is straightforward as long as you reference mark everything and re-install the parts exactly how they were to begin with, and get the caps lined up correctly on the u-joints so you don't mangle any needle bearings. I did take a medium sized hammer and whack the ears on the yokes a few times each to help seat the bearings. I read that tip online and I believe it helped a lot.

I took a test drive after getting everything back together again and the vibration is gone now. The driveline feels tighter somehow but I believe that is normal since my old u-joints were loose. I feel a very slight vibration in the gear shift but that has always been present. I ran the truck up to between 60 and 65 and felt no vibration at all like I had before. I will get it out on the turnpike tomorrow for a real test drive and be sure the vibration at 70 mph is gone. If not, the only other thing I know to check is my front rotors.

Thanks for your help on this. It was definitely a learning experience for me.

 

[Jimmy9190]

I went for a proper test drive today, went up on the turnpike where I can legally go 70 mph. Truck did fine, the bad vibration I had on my last interstate trip is completely gone. The truck rides, drives, steers and tracks perfectly. I drove today on up to 75 mph and the vibration was still gone, so the worn u-joints must have been the cause of that vibration I had at interstate speeds.

The truck still has a very slight wobble in the steering wheel between about 55 to 60 mph, but there is no vibration in the floorboard or seat. The wobble is more present when I have only one hand on the wheel. If I hold the wheel with both hands, the wobble stops. Also when I am slowing down to stop, soon as I get to between 15 and 20 mph and on down to maybe 5 mph I get a very slight brake pulsation type problem, often it sort of feels like a slight body roll. If I let off the brakes, both problems are gone. I did a test in a parking lot where I got up to between 15 and 20 mph in an empty parking lot and braked only using the parking brake and did not have the pulsation problem then either. The brake pulsation is very slight but it and the slight wobble in the steering wheel both seem to me like I may have slightly warped rotors. The rotors I currently have on the truck are almost 3 years old. They have maybe 35 or 40,000 miles on them.

My next possible solution here is new rotors. If that does not fix the steering wheel wobble I will get the alignment checked. If all else fails I will have the tires themselves checked but I can not see how tires can go bad at only 11,000 miles. The truck does sit for several days without being driven sometimes, maybe that has something to do with tires going bad, but I don't know enough about it myself. My truck sits for 3 to 4 or 5 days at a time because I work at home so often during the week I do not go anywhere unless I take a walk with my wife after dinner.

If anyone has any other info on this I would appreciate the help.

Thanks.

 

[cjcride]

Rotors then tires. The weights are still in place? Some can come off.

 

[Jimmy9190]

I just had the wheels balanced last weekend. The weights are all still there. I am going to get new rotors in the next few days and see how it goes from there. I am going to keep after this problem until I solve it.

Thanks for your help.

 

[mechtech2]

Wheels bent, tires faulty, bad balance, or bad rotor.
Any suspension looseness will cause these problems to be felt more.

 

[Jimmy9190]

Well I have an update if anyone is interested...I put a set of new front rotors on tonight, took a good test drive and the steering wheel shake and body roll/pulsation problems are all completely gone now. Everything is working fine, truck rides very smoothly for a 12 year old pickup truck with 152,000 miles on it.

I bought Wearever rotors at AAP, $47.99 each, I paid online, threw in a can of brake cleaner and a roll of electrical tape to bump the price past $100.00. I used the $40.00 discount code FABU and paid $61.00 and some change. Not too bad of a deal. Thanks everyone who helped me with this.