Questions and Answers

Ford Bronco Ratcheting Noise Q. Hello, how are you doing?? My name is Alex and I have question regarding my roommates vehicle it's a 1995 Ford Bronco 5.0 liter 4x4 5-speed Mazda transmission. Anyways this Bronco makes kind of a ratcheting noise under acceleration.

A. The U-joints are new, as is the clutch. I'm pretty sure it's the transfer case but not 100%. We recently changed the transmission oil and the drain plug was covered with metal particles. It looked like mud. I know it's normal to have some metal on the magnetized drain plug but this one had a lot and there was only 600 miles on the oil in it.

I'm just wondering if you've had any experience with a ratcheting noise in a Ford 4x4? I know it's either the transmission or that transfer case making this noise. If you could give me any advice I would greatly appreciate it. Great web site by the way I've read most of it and learned a great deal.

Thank you...

There is a TSB out on this. It is a three part bulletin so you can get a copy of the full TSB from your Ford Dealer or bring it in for them to take care of.

Article No.: 97-6-28
Date: 03/17/97

• Noise - "Ratcheting" - Front Axle - 4x4 - Self-Engagement Of Automatic Hub Locks - Bronco, F-150 And F-250 Under 8500 # GVW
• Axle - 4x4 - "Ratcheting" Noise - Self-Engagement Of Automatic Hub Locks - Bronco, F-150 And F-250 Under 8500 # GVW

Light Truck:
1995-96 Bronco, F-150, F-250 LD

ISSUE:
A "ratcheting" noise from the front axle and/or a self-engagement of the automatic hub locks may occur on some vehicles. This may be caused by a combination of high axle motoring torque and hub locks that require little torque input to engage.

ACTION:
Reduce the axle motoring torque by replacing the differential side gear thrust washers and adjusting the pinion pre-load. This procedure will reduce the axle motoring torque to a level below the required hub lock torque to engage. Refer to the following Service Procedure for details.

NOTE: the front axle should be "broken-in" for 402 km (250 miles) prior to proceeding with additional diagnosis or repairs. To break-in the front axle, engage four-wheel-drive, drive forward and then shift out of four-wheel-drive without disengaging the hub locks. Driving with the hubs engaged will break-in the axle. If the vehicle is backed up during this time period, the hub locks will disengage and will have to be engaged again by repeating this procedure.

SERVICE PROCEDURE:

Remove the front drive shaft and tie a 12-pound test monofilament fish line between the front output yoke of the transfer case and the round locator hole on the side of the transfer case (Figure 1). Drive the vehicle in two-wheel-drive with the hubs unlocked for a minimum of 3 km (2 miles), including some lock-to-lock figure eight turns. Refer to the following two conditions.

• If the fish line breaks, the concern is being generated by the transfer case. It will require further diagnosis and possible repair. Refer to Section C - Transfer Case Diagnosis And Repair of this article.
• If the fish line did not break, proceed to Section A - Measure The Motoring Torque Of The Front Drive Axle of this article and follow through all of the service procedure until the concern is resolved.