[tefuller1]

Hello everyone

I have a 2001 AWD Astro with 146000 miles on it. Today i noticed that when on a decel at around 60 MPH the van will shutter and shake until you get to around 40 MPH. I was thinkg rear diff. I do have a seperate problem with it whinning on a decel wich i think is a bad ring and pinion. Does anyone have any suggestions on where to start first. I do work as a mechanic but on big equipment and diesel trucks so a little out of my expertise. :?

 

[astro355]

I would first start by checking all of the universals. It could be the rearend but personally, I always check the easiest parts first.

 

[lesterl]

Make sure the diff's are full of fluid (full to the point they are supposed to be full)

Oh, and do you have same size/ condition tires all the way around on that AWD?

 

[tefuller1]

Yes I do have the same size tires all the way around. I just bought brand new Firestone Destination LE. I will definetely check out the u joints. I was going to services the diff's any how so i will just push that ahead a little bit.

 

[astro355]

Did you have this vibration before you put the new tires on it?

And happy birthday!

 

[tefuller1]

No shaking before the tires were installed, but the shaking started a few days ago and the tires are six weeks old. I will have the tire balance checked again or i will rotate them to see if any changes occur. I have 9 inches of snow in my driveway so it will be a while before i can get under it and check it out.

Thanks tefuller1

 

[astro355]

Definitely a good idea to check the balance on the tires and/or rotate them. So I assume that its a general shaking or is it coming from one part of the van?

 

[timelessbeing]

Snow you say?

If theres clumps of snow or ice stuck in your rims it will cause vibrations. It could be behind the spokes or somewhere you can't see it.

 

[tefuller1]

I was driving the van today and was really paying close attention to it. Several times when going down a hill it would really studder and shudder, it acted like it was trying to buck you out of the drivers seat. Then one time i turned the cruise control switch to the off position and it instantly came out of it. After that point i was not in a situation where it would normally act up. I just wanted to see if anyone had similar issue reguarding the cruise control or if it was just a coincidence. I will keep monitoring this issue.

 

[astro355]

I have seen it where vehicles would do that with the cruise control engaged but that was when going up a hill, not down it. When going up a hill, the cruise control would try to maintain speed. With the torque convertor locked, there is a spot in the powerband right before the downshift that would create a loss of power and 'jerk' the van. A tune up solved the problem.

 

[tefuller1]

Just did a tune up in October cap, rotor, plugs, wires and fuel filter. A "jerking" feeling is an accurate description of the symptom.

 

[astro355]

Is it throwing any codes?

How is your fuel mileage?

Would you go so far as to say its dieseling?

 

[tefuller1]

Fuel mileage has been lower but with the cold Iowa weather and two kids and a spoiled wife there has been a lot of warming up the van before we go out. It went from 15mpg to arounf 12 mpg. It is not dieseling at all. I just checked for codes over the weekend and there were none but will check again.

Thanks for all the input i really appreciate it.

 

[lesterl]

When I warm up my '88, and/ or drive it .9 miles, P/U kid, drive .9 miles back it still gets like 14-15 and never gets up to temp without warming up (which I usually dont do.)

 

[tefuller1]

Ok

This problem has been going on for around a month and finally the SES light came on. My code reader read code P0300 multiple random misfires. It had a new tune up in October. The troubleshooting steps in the manual are pretty extensive. Is there anyone out there have any experience with this code or any advice on where to start looking fot this problem.