Need help with vibration...

[joshua5438]

I have started getting a vibration when I take off at a normal speed. It only does it for a second and doesnt really seem to matter if I am going straight or turning. I checked the fluid in the rear end and trans and they are both full. I also checked the drive shaft and it seems tight. The rear ends seems to have normal play but I did find one thing that I am not sure about. Should the drive shaft have a little play in it where it goes into the trans? You have move it up and down just a hair. I am not sure if this is normal or not.. Anyone have any other ideas what could be causing the vibration?

 

[wydopnthrtl]

Sounds normal to me.

The next question is at what frequency is this. Is it 1:1 with the tires rotating? (Or faster)

Rich

 

[joshua5438]

I would believe its normal if I had just bought the truck but I have owned it for six years and it just started doing this about a month ago. I would say that its faster than the tires.. Its like hitting those ridges on the side of the interstate but for less than a second.

 

[wydopnthrtl]

What I meant was the input shaft slop. Not the vibrations...

So this is from 0mph to about 3-5mph?

Rich

 

[joshua5438]

oh.. That makes since. It does it from around 0 to 3 I would say. Only when it has load on it also. If I am on a hill and start to roll it will not vibrate. I hope to get under it sometime this week and check the U joints.

 

[oilwell1415]

Are you sure you don't have a misfire at throttle tip in?

 

[Hockeyman48]

Torque Converter maybe? Broken weld internally?

 

[wydopnthrtl]

I still ask... at what frequency? The driveshaft, tranny, and convertor all rotate significantly more than the tire.

By your description I'm *guessing* it's more quickly than tire rotation.

Try putting some weight in the bed. Like 500+ lb which will change the pinion angle slightly. What does that do?

Also try facing downhill and start off. What does that do?

If those things do have an effect on it.. I'd guess it's input shaft related. If not.. I'd suspect U-joints.
I've personally had different vehicles do what you describe. When the input shaft bearing was worn it had this clunking up to about 15-20mph. And the input shaft was quite a bit more loose than other cars I had felt.
I also had some bad u-joints that were dry. The little roller bearings had made grooves in the caps and when taking off from 0mph it would shudder the car, make a noise, and sometimes squeek. (real minor of a "feeling / shuffer" but noticable)

Rich

 

[joshua5438]

Are you sure you don't have a misfire at throttle tip in?

Nah. You can tell its a vibration. You can also tell its coming from the rear of the truck. I really dont thinks its the trans because it doesnt feel like a slip or hesitation. I feel it almost has to be the drive shaft or the rearend. How can we check the rearend? I checked the fluid but anything else that we can do to see if it has gotten any extra play in it?

Torque Converter maybe? Broken weld internally?

any way to check this???

 

[joshua5438]

I still ask... at what frequency? The driveshaft, tranny, and convertor all rotate significantly more than the tire.

By your description I'm *guessing* it's more quickly than tire rotation.

Try putting some weight in the bed. Like 500+ lb which will change the pinion angle slightly. What does that do?

Also try facing downhill and start off. What does that do?

If those things do have an effect on it.. I'd guess it's input shaft related. If not.. I'd suspect U-joints.
I've personally had different vehicles do what you describe. When the input shaft bearing was worn it had this clunking up to about 15-20mph. And the input shaft was quite a bit more loose than other cars I had felt.
I also had some bad u-joints that were dry. The little roller bearings had made grooves in the caps and when taking off from 0mph it would shudder the car, make a noise, and sometimes squeek. (real minor of a "feeling / shuffer" but noticable)

Rich

ok.. It is alot quicker than the tires turning. I am just starting off and it will do it for just a second. It will only do this if I am on flat ground or up hill. It doesnt get any worse on a hill either. I also do not feel it everytime I take off. I have had other people in the truck when it does it but they never feel it until I point it out so its obviously a very minor vibration. I will try to put something in the bed and see what it does. It has been lowered for about 4 years and has shim and I have never had any problems with it. I havnt noticed any squeeks or anything else out of the ordinary.

 

[BlackBolt9]

Check to make sure the rear calipers are sliding on their pins. Maybe the pads are dragging for just a second but then loosen up.