Strange Thud Noise ???

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Mar 31, 2003 | 01:04 PM

garybuch

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Strange Thud Noise ???

I have a 98 Explorer 4x4 with 67,000 miles. When driving down the road I keep hearing (and feeling) a heavy thud noice coming from the rear right side of the vehicle. I thought it was the spare tire shifting, but it is not. A mechanic friend said he thought it was backfiring. The noise is very random. My "O/D Off" light is also flashing.

Any ideas???

Thanks,
Gary

Apr 26, 2003 | 10:00 AM

gpalchk

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Strange Thud Noise ???

I had similar thud at highway speeds-felt like driving over expansion joint. Changed plugs, fuel filter, tightened spare hanger-no difference. .Got worse on hard acceleration, then the transfer case crapped out entirely in high range. $1600 to replace. sorry.

Apr 26, 2003 | 10:05 AM

gpalchk

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Strange Thud Noise ???

p.s. also 98, 91,000 miles. when case failed od light went ape. watch tach.

Apr 26, 2003 | 09:45 PM

mrshorty

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Strange Thud Noise ???

I don't really know for sure, but I thought the O/D light flashing was the PCM's way of saying that it can see a problem. If so, you may be able to hook the PCM up to a scanner and get a trouble code for the transmission and diagnose from there.
Anybody with a newer Explorer verify or contradict me here?

Apr 28, 2003 | 09:22 AM

garybuch

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Strange Thud Noise ???

The problem turned out to be the 4WD transfer case. There is an electric motor that turns a shaft that changes the gears into 4WD low and high. That shaft had enough movement while driving to cause the gears to partially engage and "CLUNK". I replaced the rear half of the transfer case housing and the problem was solved. Apparently some bushing in the case that held the shaft. Now I know why transmission guys call Explorers "Exploders". Thanks Ford.

May 13, 2003 | 07:58 PM

timbrekus

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Strange Thud Noise ???

Hey Garybuch or anyone who has solved this problem. I also have a 95 ford explorer with 4x4 package and the transmission was reconditioned in Nov. of last year however when I am driving between the speeds 50-65mph and sometimes let off the gas pedal instantly I sometimes get a loud thud or clunk like something tried to engage and shifted back to normal. What do I need to do to fix this problem.