Mechanics

VIBRATION

1996 Dodge Ram • 56,000 miles

This is a Dodge V10 2500 extended cab long bed. I have the correct tires and all. The truck has a vibration around 70 mph where it is rather noticeable, At times it goes away but always returns. I have had the tires balanced but the vibration remains. I have check the tires for slipped belts and they are all straight and feel smooth without bumps or dips. In the past I have had tires on other cars that slipped the belts so I think I know what to look for and they shook all the time. One thing could be doing it is when braking the truck pulls to the right a bit so I have felt the wheels for heat to see if I have a brake pad dragging. On unusual heat from either wheel. So I don't know what is causing the pulling to the right unless the left caliper is hanging and not letting as much pressure to the pad as the right. I intend to rebuild the calipers anyway and the pads are in good shape.

The shocks have never been replaced but I have watched the tire while going down the HWY and there don't seem to be a bounce in them. But It is lite enough vibration I am not sure I could see it. One other thing I have done is jack up the rear end and with one tire on the axle ran the the truck up to 70 mph and there was no vibration, done this with each wheel and tire, but the contact to the ground was solid do to the jack stands under the rear axle.
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Falconview
July 10, 2013.



Check all your ujoints in the driveshaft. If you see rust around the seals then they are bad.


Hmac300
Jul 10, 2013.
I will take a look at those Ujoints today and replace as needed. I have check them before by putting the truck in forward and then reverse to hear for a clunk sound, haven't notice that sound yet.

If the ujoints don't have ware on surface where the needle bearing ride should the ujoint be replaced? I have had ujoints that had ware pattern on the shaft under the cups and replace them, checked them a year or so later and had the same ware pattern (not on this truck). Should I pack the new ujoints with hi-pressure grease. Before I only used the regular grease to grease them if they had a fitting to grease with or didn't grease them because they come new with grease on the needle bearing. I have been told that is junk grease, is that true?


Tiny
Falconview
Jul 11, 2013.
There shold be no marks indicatitng a wear pattern. Using regular grease is fine as it is mostly good for ujoints, /wheel bearings etc. If you have a center support bearing check that as well. Of course this could be something else like engine or transmission as well. Also one other thing. Spray water on your belt and see if anything is going on there. Recommended replacement of belt &tensioner is 60k and you are nearing that. See pic for center support bearing.


Hmac300
Jul 11, 2013.
I can't believe so little ware would cause that much vibration. Two ujoints showed sighs of ware on one post each while the third was in good shape but replaced it anyway. Those were the hardest ujoints I had ever replaced. Vibration mostly gone. The center support bearing had no slop in it so I didn't replace it. I had replaced the belt at 50k but have not replaced the tensioner. Tomorrow I get my transmission fluid thermostat bypass. Will be installing 2 more coolers because when my total weight is over 14K towing my travel trail in slow and steep long hills the tranny gets rather warm by the fluid temperature gauge I installed. It top out at 260 degrees on one hill. Out on the open road there is no problem of it getting hot right around 160 degrees or less with the torque converter locked, plenty of air flow through the stock tranny cooler. On hills at HWY speed with the torque converter unlocked the temp will move up to 200-220 degrees. This truck is equipped with a tow package but just doesn't have the cooling needed for the tranny. I now see how others burn up their transmission by pushing too hard. I have plenty of engine but the build up of heat in the transmission is a limiting factor of how much power to apply. I have been changing the fluid and filter every 25K and adjusting the bands. After installing the cools got to figure out what causing the truck to pull to the right while braking.


Tiny
Falconview
Jul 11, 2013.
I intend to do a flow test of the tranny fluid when installing the new coolers. What I have found, with out flow line unhook at the cooler with the engine at idle I should get a quart or more of fluid in 10 sec and no fluid coming out the other end that is open.


Tiny
Falconview
Jul 11, 2013.
260 isn't a bad temp going uphill with a load, long as it isn't sustained and not allowed to cool down. Glad you got rid of vibration though.


Hmac300
Jul 12, 2013.