Vibration at certain speed.

[CarlosM]

Ive had this truck for about 2 months. 2017 v8 Bought with 49k. Lately I’ve noticed this vibration feel when I’m from 36mph-42mph then it just goes away. Same happens if I’m slowing down, when I hit about 42mph it vibrates a little and once I go under 36mph it stops. I know MDS can make your truck feel weird due to the 4clnd being shut down, but i drive my truck on 8th to avoid ECO kicking in. I use 89 fuel and my tires were balanced about 1month ago. I haven’t checked MAS or sparks yet, but Is this something that I should be concerned about down the road?

 

[pacofortacos]

Is it the whole truck, just the steering wheel, or do you feel it in the brake pedal at all.

Could be a ujoint/driveshaft, bad belt in a tire, caliper hanging a bit, warped rotors.

What happens if you drop into 6 or 7th gear? Is it just mph related or rpm related?

 

[CarlosM]

I feel it mostly on the truck and the steering wheel( its minimal, but noticeable) I tried droping it to 7th while keeping the same speed where the vibration happens and it did not go away. It’s just mph related. It seems rpm’s don’t affect it.

 

[CarlosM]

Is it the whole truck, just the steering wheel, or do you feel it in the brake pedal at all.

Could be a ujoint/driveshaft, bad belt in a tire, caliper hanging a bit, warped rotors.

What happens if you drop into 6 or 7th gear? Is it just mph related or rpm related?

I should also mention I took the rear part of the shaft down to grease up the slip yoke since I also have the bump feel when taking off or breaking. Im not that great of a mechanic, i don’t think the shaft is out of balance but just thought I should mention that.

 

[fireflymedic]

If you know someone else with a ram truck you could swap tires and see if it goes away. Or put your spare on each corner and see if that helps (this will only work if its just one bad tire. If you have a gopro camera you could video each tire and see if any tire is bouncing. Obviously it's something spinning and tires and drive shaft would be the main culprit I would think.

 

[pacofortacos]

I should also mention I took the rear part of the shaft down to grease up the slip yoke since I also have the bump feel when taking off or breaking. Im not that great of a mechanic, i don’t think the shaft is out of balance but just thought I should mention that

Did it have the vibration before you did that? If not, you might try pulling it off of the rear differential again and rotate the driveshaft 180 degrees.
Are the u-joints good - any play in them at all? When they start to go bad, you will get a vibration.

 

[CarlosM]

Did it have the vibration before you did that? If not, you might try pulling it off of the rear differential again and rotate the driveshaft 180 degrees.
Are the u-joints good - any play in them at all? When they start to go bad, you will get a vibration.

I cant really remember if it did it before taking down the shaft. I checked the u-joints and they didn’t have play(right the u joints ) but the shaft does have a little bit of play, my understanding is that it is supposed to have some play.

 

[CarlosM]

If you know someone else with a ram truck you could swap tires and see if it goes away. Or put your spare on each corner and see if that helps (this will only work if its just one bad tire. If you have a gopro camera you could video each tire and see if any tire is bouncing. Obviously it's something spinning and tires and drive shaft would be the main culprit I would think.

All 4 tires are pretty much new, they are falken wildpeak. And the vibration only happens for a few miles and goes away. If it was the tires, wouldn’t it be a constant vibration?

 

[pacofortacos]

There might be a little play in the rear pinion and front slip joint but both ujoints should have zero play between the driveshaft and what they are bolted to.

Wait, are you saying that the vibration is only there for a few miles and then disappears at any speed? If so, that is tires, most likely just getting a flat spot from sitting or a bad belt in a tire - after they warm up they tend to be a bit more flexible.

I get this with my XL generals - but my truck sits in one place for weeks on end, so I would expect flat spots.

 

[1979PowerWagon360]

Sounding like tires now. Have you popped it in neutral during these speeds of vibration to see if you still feel vibration? That's something else I'd try to help rule out certain things with harmonic vibrations.

 

[DILLIGAF]

Ive pull my rear driveshaft off and when for a drive in 4wd obviously...lol... . Best way to see if its related.

And Do the same for the front drive shaft. Pull it and go for a rip !

 

[18CrewDually]

To rule out the cylinders dropping out, I believe if it is in Tow/haul mode it will not drop out cylinders. Try driving it in tow/haul and see if it is gone.

 

[turkeybird56]

To rule out the cylinders dropping out, I believe if it is in Tow/haul mode it will not drop out cylinders. Try driving it in tow/haul and see if it is gone.

Does kinda sound like tires and it goes away after a few miles, as in tires/psi heating up, just IMHO...

OP; Check tire pressure on vehicle when cold and confirm all the pressures are at indicated PSI when cold. Go by sticker in drivers door. And also use a good digital gauge to check each tire, DO NOT GO by TPMS. Also would help if you had a compressor with an air chuck at yer place. If U have to drive a few miles to get "air", understand air heats up on tire rotation and the readings, depending upon ambient temp outside may be 1-3 pounds higher than when tires are cold.

 

[18CrewDually]

Does kinda sound like tires and it goes away after a few miles, as in tires/psi heating up, just IMHO...

I agree could be, I have these tires too and it took a bit of weight to balance. I've read others complain about balancing them too. Its probably worth it for him to get them rebalanced no matter what the mileage is.
But taking the driveshaft apart and greasing it can cause issues too if you use the wrong grease, too much grease, improperly re-installed. There is a high pressure high heat synthetic Silicone base white grease I use on driveshaft splines. Regular grease does not cut it.
He just has to start ruling things out and figure out if this was always a problem or one he has caused.

 

[turkeybird56]

I agree could be, I have these tires too and it took a bit of weight to balance. I've read others complain about balancing them too. Its probably worth it for him to get them rebalanced no matter what the mileage is.
But taking the driveshaft apart and greasing it can cause issues too if you use the wrong grease, too much grease, improperly re-installed. There is a high pressure high heat synthetic Silicone base white grease I use on driveshaft splines. Regular grease does not cut it.
He just has to start ruling things out and figure out if this was always a problem or one he has caused.

Yeah, Internet Guessnosis at i's best. Been a while since I pulled a shaft and greased, usually just put in neutral and rotate and grease thru grease fitting, but have no idea if there are even any fittings on the u-joints these days, guess gotta crawl under my 2019 and look. I have read of a grease fitting on the front shafts of the 2500's that requires occasional greasing, but have read the 1500's do not have them, and OP's avatar says 2017 V8, not a lot of info to go by. (missed the spline part, but would hope joints done also, since had shaft out, just a thought).

Just really sounds like a Tire issue, but U also neva know.

YEAH, "INTERNET GUESSNOSIS". Sometimes we even get close, LOL.

CAVEAT: Reading OP's post, he has Falkens on truck. I have Falkens on my truck, and you have to know what U R doing to get balance done correctly, usually need Road Force, and a lot of shops PPL really do not know what they R doing. When I bought my Falkens, I have 3 tires that have weight, and one tire that balanced out less than/over -5/+5, so no weight on that (1) tire, weird, but how it is.

 

[18CrewDually]

Yeah, Internet Guessnosis at i's best. Been a while since I pulled a shaft and greased, usually just put in neutral and rotate and grease thru grease fitting, but have no idea if there are even any fittings on the u-joints these days, guess gotta crawl under my 2019 and look. I have read of a grease fitting on the front shafts of the 2500's that requires occasional greasing, but have read the 1500's do not have them, and OP's avatar says 2017 V8, not a lot of info to go by.

Just really sounds like a Tire issue, but U also neva know.

YEAH, "INTERNET GUESSNOSIS". Sometimes we even get close, LOL.

Post #4 he states the splines so he pulled the driveshaft. That is what I'm referring to.

 

[turkeybird56]

Post #4 he states the splines so he pulled the driveshaft. That is what I'm referring to.

Yup yup.

 

[CarlosM]

There might be a little play in the rear pinion and front slip joint but both ujoints should have zero play between the driveshaft and what they are bolted to.

Wait, are you saying that the vibration is only there for a few miles and then disappears at any speed? If so, that is tires, most likely just getting a flat spot from sitting or a bad belt in a tire - after they warm up they tend to be a bit more flexible.

I get this with my XL generals - but my truck sits in one place for weeks on end, so I would expect flat spots.

The play Im talking about is if I go under the truck and I grab the shaft and turn it, it turns a little bit, there is not play at the ujoints(that I know of). And yea the vibration is only there from 36mph to 42mph then goes away. These were used when I bought them but pretty much new. How do I check if it’s a bad belt? And my truck is my daily so it gets driven everyday.

 

[CarlosM]

I agree could be, I have these tires too and it took a bit of weight to balance. I've read others complain about balancing them too. Its probably worth it for him to get them rebalanced no matter what the mileage is.
But taking the driveshaft apart and greasing it can cause issues too if you use the wrong grease, too much grease, improperly re-installed. There is a high pressure high heat synthetic Silicone base white grease I use on driveshaft splines. Regular grease does not cut it.
He just has to start ruling things out and figure out if this was always a problem or one he has caused.

I used a high temp mobile 1 grease, go easy on me, i ain’t no mechanic and this is my first truck. Now I’m reading here there other better stuff than grease to grease up the slip joke. I should mention when I pulled it out it was dry, not a single bi my of grease in there. But going back to the vibration, I’ll get the tires rebalanced and check PSIs, i know the shop I got them installed at put them at 40psi.

 

[18CrewDually]

Now you reveal the tires were actually used. The more this goes on the more you need to have the tires checked out. Maybe a weight flew off and it became unbalanced. Unfortunately these tires don't have the best history of being well balanced. But I went with them mostly for the miles people reported getting out of them. They may appear like new to you but may have 20k miles on them and be 3 years old. Used is used.