Hey y'all. I have a 1983 Chevy Silverado 1/2 ton with the 305ci engine and it is 2wd. When I am driving at about 60mph and up there is a pulsating vibration. It is slower when I am at that speed and going down a hill where it doesn't require much gas to keep up the speed and when I am going up a hill and using the engine more to keep up my speed, it pulses faster. After doing it for a long time, it can start to be more audible sounding like some subs going along with the pulses. Any ideas? I am thinking it is either the rear diff. or the tranny. Thoughts? The fluid in the tranny is a little off color but not too bad.

 

I would go with the rear diff or the drive line and U-Joints. That is where I would start.

Good luck and let us know what you found.

 

Make sure you dont have a "Bubble" in one of your tires. Thats what it does when the belts start splitting.

 

How would I be able to tell if there is a bubble in one of my tires? I bought the cheapest tires I could get this last time. They are Dean Alpha tires... 50,000 mile warranty though so if one is bubbling I will get it replaced.

 

Well I seen some Michelin's go bad too so it just happens. Any tire shop can look at them for you. Or if you have a jack you can see for ur self. Does it do it when you go really slow like say 5 mph??

 

Nope, only at higher interstate speeds over 65 mph.

 

What would I be looking for. I definitely have a floor jack so it wouldn't take any time for me to lift the truck off the ground.

 

Turn the tire and feel the tread you should feel a bump or the tread rise or even the tread could widen. Then look at the sidewalls, main thing is to releave all the presure off the tire before doing it.
You can also spin the tire and look at it to see if it is mounted wrong or the wheel could be bent.

 

I will check that out this weekend when I have a few minutes. Thanks a lot!