Knocking on deceleration ford explorer 1997 4x4 4.0 EFI V6

[Loïc ESTIVALS]

Hello everyone,
I have a Ford Explorer 1997, 4x4 V6 4.0L EFI,
A knocking is heard every time it decelerating, but when i accelerating or clutching the noise disappears.
The noise it's more strong in slow velocity.

I have rebuilt the gearbox and the transfer case, i have buy a new disc, plate and clutch spring.
I have changed the suspension, the stabilizer bars and rods, I repaired the rear crown.

Probe to remove the front cardan of the 4x4 but the same makes the noise, I remove the chain of the transfer case and did it too.

Now I do not know where this knocking problem can come from, Can it come from the engine chains? Is heard in front of the gearbox.

I thank you of advances for your help, I do not know what to do and I do not want to damage my car
Loïc

 

[Rick]

A damaged or worn connecting rod bearing will produce knock under all speeds. During the early stages of wear, connecting rod noise may be confused with piston slap or loose wrist pins. Connecting rod knock noise increases in volume with engine speed and is at its loudest on deceleration.

The following are causes of connecting rod bearing noise:

• Excessive bearing clearance
• Worn crankshaft connecting rod journal
• Thin, diluted or dirty oil and/or filter
• Low oil pressure
• Crankshaft connecting rod journals out-of-round
• Misaligned connecting rod
• Connecting rod bolts not properly torqued
• The wrong bearing inserts or misaligned bearing half

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A loose or cracked flywheel will produce an irregular thud or click. To test for a loose or cracked flywheel, operate the vehicle at approximately 32 km/h (20 mph) and shut off the engine. If a thud is heard, the flywheel may be loose or damaged. This type of thud is loudest on deceleration. Loose torque converter-to-flywheel or flywheel-to-crankshaft bolts will sound similar to bearing knock. This condition produces several raps during quick acceleration on a free running engine. Depending on the idle smoothness, when the transaxle is in gear, the noise may or may not appear. Check the torque converter-to-flywheel and the flywheel-to-crankshaft bolts before attempting to investigate any bearing-related knock.

 

[Loïc ESTIVALS]

Thank you for your reply, tomorrow i want check this, i want take a movie of the noize
Loïc