Vibrations in 2nd and D, not in 1st or N - only under load
#1
04-21-2017, 01:26 AM
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Vibrations in 2nd and D, not in 1st or N - only under load
89 B250 5.9L, 3 speed auto
I noticed I get a pretty bad vibration at about 20mph and it continues as I increase with speed, with some speeds not being as bad as others. Here are the combinations I've tried to figure out what it is:
-Engine braking in 1st and 2nd down a hill, no vibrations
-Coasting down a hill in D at 40mph, no vibrations
-Cruising in 1st, no vibrations
-2nd gear up a hill gets vibrations around 20mph, switch to 1st gear and maintain speed = no vibrations. Switch to D while maintaining speed, vibrations.
The u-joints felt solid, and were replaced about 50k ago. I pulled the driveline anyway just to check, they feel great.
Right engine mount was in terrible shape, I replaced that today. Engine vibration is actually more obvious now. I'm thinking I'll take a closer look at the transmission mount tomorrow and possible replace it. Engine needs a timing chain too, hopefully that gets it running smoother.
Transmission fluid smells and looks good, is topped off. I haven't dropped the pan, probably will wait till after my trip in a week to do that just in case the new fluid doesn't mesh well.
Anyone have any other thoughts on what it could be? Not sure if this is common or not, really hoping its not a transmission problem...though, it's starting to look like it likely is.
I noticed I get a pretty bad vibration at about 20mph and it continues as I increase with speed, with some speeds not being as bad as others. Here are the combinations I've tried to figure out what it is:
-Engine braking in 1st and 2nd down a hill, no vibrations
-Coasting down a hill in D at 40mph, no vibrations
-Cruising in 1st, no vibrations
-2nd gear up a hill gets vibrations around 20mph, switch to 1st gear and maintain speed = no vibrations. Switch to D while maintaining speed, vibrations.
The u-joints felt solid, and were replaced about 50k ago. I pulled the driveline anyway just to check, they feel great.
Right engine mount was in terrible shape, I replaced that today. Engine vibration is actually more obvious now. I'm thinking I'll take a closer look at the transmission mount tomorrow and possible replace it. Engine needs a timing chain too, hopefully that gets it running smoother.
Transmission fluid smells and looks good, is topped off. I haven't dropped the pan, probably will wait till after my trip in a week to do that just in case the new fluid doesn't mesh well.
Anyone have any other thoughts on what it could be? Not sure if this is common or not, really hoping its not a transmission problem...though, it's starting to look like it likely is.
#2
04-23-2017, 02:40 PM
As I see your culprit could be one or a couple of things. Recommend beginning with the cheapest fix or possible fixes first.
Even though you state the vibration is coming from underneath and not from the corners(wheels) a out of balance wheel or a damaged front hub, rear axle also a wheel bearing could be the cause.
A bad wheel bearing likely would be noisy a very worn ball joint can cause violent vibration but would DEFINITELY change or go away when you lifted on the throttle and or apply the brakes so personally I would check the joints for play.
One last thing I can pull off the top of my head is a question and it is did you check the balancing weights on the drive shaft? If the van sat for some time outdoors the drive shaft weights may have rusted off. If they did fall off the previous mounting
spots should be obvious.
Even though you state the vibration is coming from underneath and not from the corners(wheels) a out of balance wheel or a damaged front hub, rear axle also a wheel bearing could be the cause.
A bad wheel bearing likely would be noisy a very worn ball joint can cause violent vibration but would DEFINITELY change or go away when you lifted on the throttle and or apply the brakes so personally I would check the joints for play.
One last thing I can pull off the top of my head is a question and it is did you check the balancing weights on the drive shaft? If the van sat for some time outdoors the drive shaft weights may have rusted off. If they did fall off the previous mounting
spots should be obvious.
Last edited by iodj44; 04-23-2017 at 03:12 PM. Reason: .
#3
04-23-2017, 04:54 PM
