Trans. Whinning or ZZZZZ Sound

[jamesjedi]

Hi,

I am new here. I hope I can get some insight.

I have a 2002 Chev Venture van that is whinning or making a ZZZZZ sound. It sounds like it is coming from the transmission, or, in the very least, from the front. The sound is always there. I have no engine fault codes on my OBDII scanner. Wife says it is not shifting all that well. The sound does not increase with engine RPM's, it does increase with wheel speed. Problem is not intermittent.

I just jacked the car up and checked the wheel bearings by wiggling the tires at the 12 o'clock and 6 o'clock positions. They have almost no movement.

Any thoughts? Thanks.

[merc81]

You can't check the bearing that way. Even completely shot, the bearing won't reveal itself by moving enough to feel. Bearings make a rumble sound that changes intensity as you drive around bends.

Tranny whine can be bad, bad, bad. I had one that whined for a couple years, but the whine increased with temp, and it shifted fine when cold. When that one finally did go bad the whine was very loud and it was there as soon as the van started when cold.
That lasted two days--then I had to have it towed home. It has a new tranny now.

Not what you want to hear I'm sure, but forewarned is prepared.

[jamesjedi]

Thanks for the reply. It does not get louder when turning, I have driven it around in circles, both ways and have not heard any louder sounds. It is hard to diagnose because it only happens when driving.

Could it be these pressure valves that I have seen posted. I do not have any engine fault codes.

[lesterl]

Is the trans fluid full? Is it frothy? Have you had the filter changed in the trans?

[jamesjedi]

Yes, I changed the fluids and filter. Fluid looks and smells OK. I am going to check the propellor shaft and the drive shaft/axel tomorrow. Not to sure what to look for, other than the obvious things like bolts missing and fluid leaking. Perhaps they would feel loose if worn?

[merc81]

Wife says it is not shifting all that well

What did you mean by that?
When the TCC solenoid needs to be replaced, you should notice hard shifts most of the time, but really bad after things get warm. It might get so bad that when coming to a stop from above 50mph the van can buck & stall because its still in gear.

The line pressure gets cranked up by the ECM trying to compensate for the stuck valve, but that only works for a while it seems, and that increased line pressure causes the whine most people hear when they have the TCC lockup problem. This usually sets a code, but I have gone for a month or more of hard shifting, and not seen the light come on.

Heat and dirty fluid make the valve problem worse, so a transmission cooler ($50) and fresh fluid/filter always helps.

There are no propeller shafts to check unless you have all wheel drive (in which case I retract everything I've said). The drive shafts run directly from the transmission to the wheel bearings. CV joints that go bad really ought to give themselves away as you turn the van.
Sounds like transmission to me.

[jamesjedi]

The left side wheel drive shaft feels a little loose. There may be a little additional noise when turning. Yes, you right...it is front wheel drive. Silly me.

I may take it out to have a better look.

[merc81]

Get the van up to highway speed--drop it into neutral and coast for 20 seconds or so. Does the sound change with the drop in engine speed or does it remain the same? Wheel bearing and CV joints are your only source of sound/vibration in the driveline and those will be unaffected by engine rpms.

Transmission whine/shudder will track the engine rpm...

[jamesjedi]

I did that last night. The sound stays the same. I am staring to think that this is the problem.