Wheel bearings a likely source of clicking noise

Hey there, time traveller!
This article was published 17/08/2007 (6620 days ago), so information in it may no longer be current.

Q I own a 2003 Montana extended van and recently noticed a noise (similar to a playing card against a bicycle wheel) that occurs only when I turn right at normal speed. If I slow down there is no noise. I have taken it to three garages including GM and they have changed the axles twice and had the wheel bearings done. Still the noise exists and they are thinking transmission, except for the transmission garage. Before going ahead with the expense of a transmission, any solutions that you may have before moving to a possible transmission job.

A. The ticking or clicking noise you have described sounds like a worn axle joint or damaged wheel bearing. Because the axles have already been changed, we can eliminate them as the source of the problem. A worn axle would also likely make noise turning both ways and at slower speeds too. That leaves the wheel bearings.

You say you have had the wheel bearings done. I am not sure exactly what that means. Have they been replaced? Were they disassembled and inspected? Were they simply spun to feel for bad spots? Even if you have had a wheel bearing replaced, I would still look there first as the source of this problem.

When you turn a corner, centrifugal force is placing more weight on the wheels on the side of the vehicle away from the turn. For example, if you turn right, the left wheel bearings have the most load. If you turn left, the right wheel bearings receive the load. Your noise only occurs during right hand turns, so the left wheel bearings are suspect.

The noise could be coming from either the front or rear wheel bearings on the left side. Noise can transfer throughout the body and it can be difficult to determine where it originates. You might need to replace both front and rear. I have worked on several vehicles that had this problem and even inspecting the bearings with a magnifying glass wouldn’t visually show any faults. After I replaced the bearing however, the noise was gone.

The transmission differential could cause noises during turns but I would expect it to occur when turning either direction. Therefore, I agree with the transmission shop and think the problem is not there.

One last thought: if your vehicle is all wheel drive, inspect the driveshaft joints for binding and wear. The front and rear axles follow different paths during a turn and this places force on the driveshaft joints. A bad one could make noise.

Q. I have a 1998 Windstar van and have towed an older tent trailer until I cooked the tranny three years ago. Since the new transmission I have not towed anything. The Windstar has an automatic tranny with an overdrive which can be manually switched off. I also have an after market transmission cooler installed.

I left the overdrive on when towing because I was in the prairies and usually on flat roads. When I encountered hills I would take the overdrive off. You have suggested that towing with overdrive off is the best way to go. My question is, won’t this increase the cost of fuel? Revolutions per minute go to 3000 (overdrive off) from 2200 rpm when in overdrive. Also, is this not hard on the engine to drive long distances at high rpm? Does the transmission really work less hard, and cooler when the engine is revving more but out of overdrive? I am thinking of getting another trailer so I would appreciate your feedback.

A. Shifting out of overdrive will cause engine speed to go up, but you won’t use as much extra fuel as you might expect. Because there is more gear advantage, there is less load on the engine and you won’t need to press on the accelerator as hard. It will use more fuel but not enough to be a major factor.

Is high rpm hard on an engine? Extremely high rpm places more load on internal parts, but 3000 rpm isn’t that high for most engines. I have driven thousands of kilometres with engines running at 3000 rpm or more without significant extra wear or engine problems. Just make sure you are using quality oil to handle the additional heat.

For your final question, the transmission does operate cooler when the torque converter is not multiplying the torque. Most of the heat created in a transmission is caused by slippage in the torque converter. Using a lower gear provides a mechanical gear advantage and takes some of the load or slippage off the torque converter. The result is a cooler running transmission.

Jim Kerr is an experienced mechanic, instructor of automotive technology and member of the Automobile Journalists’ Association of Canada. You can e-mail questions to Jim at the address below.

kerr.jim@sasktel.net