Help needed, 97 explorer which make buzzing noise when de-accelerating

[richien13]

Hi everybody

Hope somebody can put me in the right direction, i have a 97 Ford explorer with a manual M50D-R1 transmission, done 200,000 miles. Vehicle pulls ok in all gears, when i de-accelerate i get what sounds like gears grating (a buzzing noise) when i accelerate again its ok. What is the likely cause? Any help would be greatly appreciated.

Richard

 

[IZwack]

Hey welcome to ExplorerForum and congratulations on 200,000 miles! That in itself calls for celebration!

As for the noise, park the vehicle and block off the wheels so that it cant roll away. Then disconnect the rear driveshaft ("propshaft" for the Euros and Aussies ) and check for any up/down or left-right play ("looseness") in the rear axle's yoke.

My thought is that the rear axle's pinion bearings are worn and/or loose and needs service -- which is pretty good considering it has been rotating for 200,000 miles now.

 

[richien13]

Hi IZwack

Ill try that today, really wondering if it could be the gear getting ready to give out, all the research done so far i can't work it out.

Richard

 

[IZwack]

Gearsets dont really give out unless you run it really loose for a long time -- which if you did, could cause damage to the gears as they are not kept properly inline and are not meshing or contacting properly.

On my brother's 97, it ran maybe two hundred miles or so with a loose rear pinion. We disassembled it, changed the bearings and seals, and the noise disappeared.

 

[richien13]

Hi IZwack

Have looked at what you suggested although not 100% sure i was looking at the right thing as i didn't really see any major difference with the driveshaft disconnected. Anyway there does not seem to be any excessive play anywhere.

Took it out for another drive to see if i could fathom out anymore detail. Still on de-acceleration getting the buzzing noise convinced it is metal on metal i.e. gears grinding, cannot work out why or which mechanism, started thinking the transfer case could be at fault in some way.

Anyway sometimes when putting it in gear (any gear) i get the same grinding noise (i can feel it through the gear lever) untill i accelerate and then it goes away, can't work out what mechanism will be ok when load is on it drive is normal but when load is reversed i.e. de-acceleration i get the noise.

Richard