Strange knocking clunking front end problem.

1995 Ford E250 4.9L L6, cargo van 176k miles.

Alright the problem is as follows... When driving at slow normal speeds going straight i get this horrible repeating knocking/clunking sound seemingly coming from below the center rear of the cockpit floor, though perhaps more towards the front right wheelwell.. It is difficult to pinpoint exactly where the sound is coming from. The sound is similar to the semi-random but cyclical thud, thud, thud sound you get when putting a pair of shoes in the drier. The sound only happens at 'neighborhood speed' going straight, if i get over approx 35 mph it goes away. Also if I'm making a sharp turn in either direction it goes away. I've tested this out in a parking lot- when driving circles in both directions there is no knocking. The sound also *immediately* stops anytime I apply the brakes even lightly. And of course, there is no sound when parked or idling. The smoothness/roughness of the road being driven seems to have no effect. I can be driving on a perfectly smooth blacktop parking lot and still get the sound.

There is also a noticeable 'CLUNK' whenever I first engage the drivetrain. ie from parked to 'D' or from 'D' to 'R' .. or parked to 'R' .. etc.. though this may be normal for the van.

This may be entirely unrelated, but the van also makes a deep vibration/rumbling on the highway from 55-70mph... which is another problem I'm working on fixing. Tires were already balanced twice. I already replaced the u-joints and plan to check out the front wheel bearings and replace the transmission extension housing seal tomorrow as it was leaking. If these don't help I may take the driveshaft to be balanced.

Tomorrow I'll be jacking up the front end to swap out the tranny filter, fluid, and extension housing seal + bushing. I'd really appreciate any pointers for items to inspect while I'm under there or any further tests I can do to try and narrow down the problem spot... keep in mind im only a beginner/novice here.

much thanks as always Jay

Reply to
Ford Warrior
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First of all, be safe. Don't jack that sucker up, take off the wheels, and then crawl under it. Support it like you life depends on it.

Some of what you are describing sounds like disk brake related noise. They can look okay and still clatter and rattle, especially if they weren't assembled properly by the last guy who worked on it.

And I think you should definitely have a look at the wheel bearings. It may not be easy to tell if they are defective just by looking. You can clean them, see how freely they rotate, and look for damage or 'burned' areas on the rollers, but in some cases it is easier just to replace them. Some vehicles have the bearings in integral hubs, others are bearing and race sets. Always replace the race with the bearing.

Rear axle bearings can also cause noise and are often overlooked.

Differential bearings and gears can cause noise.

Look over the suspension for loose components, ball joint wear or damage, scrubbing, etc as long as you are under there.

Reply to
HLS

Check your driveshaft u-joints or center bearing (if so equipped).

Professor

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Professor

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scott and barb" .

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