Expy transmission problem

jwilson645 · #1 (**permalink**) 11-03-2009, 09:44 AM

We have a 2006 Expy that we bought new. At 20k miles it went in for warranty work on the transmission because it had a really bad shudder from take off. They replaced the valve body in it. It has never been "right" and still shuddered periodically but would never do it when we took it to the dealer (so they say).

It has 97k on it now and recently a noise has appeared that I can not pinpoint where it is coming from but it seems to be speed related (starts at 40mph) and coming from something that is turning. Hard to explain a noise but I'll try.

Say you have a screw in a tire, you can hear it hit the pavement as it makes a revolution. This is a similar sound but it more like metal to metal. I've checked brakes, wheel bearings, etc but it's hard to find since it doesn't start until 40mph.
I know it's hard to diagnose a sound but just wondering if anyone has had a similar problem that might know what I'm talking about?

alloro · #2 (**permalink**) 11-03-2009, 11:42 AM

Does it make the sound once every wheel revolution, or more, or less?

jwilson645 · #3 (**permalink**) 11-03-2009, 11:51 AM

I'm not sure if it's a wheel revolution or a drivetrain revolution. It's hard to tell.

bumparker · #4 (**permalink**) 11-03-2009, 12:45 PM

Does the noise change when turning one direction or the other? Does the noise change when the suspension loads and unloads (like going over a dip in the road)? It sounds a lot like a front wheel hub (in the old days it was a wheel bearing) may be worn out. I had one go out about the same mileage, it felt like a bad tire and made a sort of humming noise that became more of a drone at higher speeds. At 120k I'm getting ready to change the other side as it is making noise now.

bumparker · #5 (**permalink**) 11-03-2009, 12:51 PM

One other question, does your shudder only occur when starting from a standstill? And does it only occur from a standstill when you are turning right or left? Does it never occur from a standstill when you drive straight?

jwilson645 · #6 (**permalink**) 11-03-2009, 01:06 PM

The noise is unchanged when turning. It doesn't start until I hit 40mph and the sound changes slightly when the tranny shifts in/out of OD.

Unit bearing was the first thing I thought of but they seem to be tight and I couldn't get a sound out of them by just free spinning them by hand. Also, no noticeable difference in the ride/drive.

I'm leaning toward the torque converter. I had someone else mention that if the valve body had went bad before it may have caused the TC to prematurely fail also.

alloro · #7 (**permalink**) 11-03-2009, 01:17 PM

A torque converter problem is related to engine speed, not vehicle speed. How about the u-joints in the drive shaft? At 40 MPH the drive shaft could be spinning fast enough to strain a sticking u-joint and cause the clicking noise.

jwilson645 · #8 (**permalink**) 11-03-2009, 05:37 PM

That's a possibility. I'll slide under there tonight and check them out.