Join Date: Mar 2006
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'92-'93's had a tensioner with the external spring.The best repair is to find a newer p/s bracket with the internal spring tensioner and install.Also install the shortest belt that will go on.
TSB 95-5-22 ACCESSORY DRIVE BELTS - ALL 7.3L IDI DIESELS - COME OFF ACCESSORY DRIVE PULLEYS - VEHICLES BUILT AFTER 2/15/92
ENGINE - ALL 7.3L IDI DIESELS - FRONT END ACCESSORY DRIVE MISALIGNMENT - FEAD BELT TRACKING ISSUES - VEHICLES BUILT AFTER 2/15/92
Publication Date: MARCH 13, 1995
LIGHT TRUCK: 1992-1994 ECONOLINE, F-250, F-350, F-47
This TSB article is being republished in its entirety to include the latest level parts and to update the service procedure.
Some diesel-powered vehicles are experiencing drive belt tracking concerns. This is caused by Front End Accessory Drive (FEAD) misalignment, which may result in the belt coming off the accessory drive pulleys. If this occurs, several warning lights will illuminate and the vehicle will lose generator and A/C function and water pump circulation. In addition, steering efforts will increase and, after one or a few brake applications, brake efforts will progressively increase.
Check and align the FEAD. Replace worn pulleys, A/C-P/S-V/P (air conditioner - power steering - vacuum pump) bracket and tensioner and install rubber-backed belts. Refer to the following Service Procedure for details.
Disconnect the battery negative leads from all batteries.
NOTE: COMPONENTS INSTALLED BY FINAL STAGE VENDORS ARE NOT INCLUDED. REMOVE THOSE COMPONENTS AS NECESSARY TO CHANGE THE A/C, P/S AND V/P BRACKETS.
Remove the air intake tube on F-Series. Also, reduce coolant and remove the radiator top water hose.
Remove the fan, clutch and shroud (LH thread on fan clutch nut). Use Fan Clutch Pulley Holder T83T-6312-A and Fan Clutch Nut Wrench T83T-6312-B.
Remove the belt from the tensioner and discard.
Remove the vacuum pump and power steering pulleys using Steering Pump Pulley Remover T69L-10300-B.
Remove the A/C compressor, vacuum pump and power steering pump from the bracket.
NOTE: IT SHOULD NOT BE NECESSARY TO BREAK ANY HOSE CONNECTIONS.
Remove the bracket, tensioner and routing idler from the cylinder head.
Install the A/C-P/S-V/P bracket (F4TZ-19E708-D) to the cylinder head. Tighten the three (3) fasteners to 47.5 N-m ±7.2 N-m (35 lb-ft ±5 lb-ft). Refer to Figure 1.
Figure 1 - Article 95-5-22
Install the tensioner (F4TZ-6B209-C) using the T50 Torx bit and tighten to 62 N-m ±9.4 N-m (46 lb-ft ±7 lb-ft). The sub-bracket is attached to the flange on the main bracket adjacent to the vacuum pump location. Use two (2) new bolts (N605906-S2) and nuts (YF-1581) and torque to 27 N-m ±4 N-m (20 lb-ft ±3 lb-ft).
NOTE: THE TENSIONER LOCATING PEG MUST BE IN THE BRACKET HOLE BEFORE TIGHTENING THE TORX BOLTS.
Reinstall the vacuum pump. Tighten the three (3) bolts with a 10 mm socket to 27.5 N-m ±4.2 N-m (20 lb-ft ±3 lb-ft).
Reinstall the power steering pump. Tighten the three (3) bolts with a 17 mm socket to 47.5 N-m ±7.2 N-m (35 lb-ft ±5 lb-ft).
Reinstall the A/C or non-A/C idler pulley and torque to 27.8 N-m ±4.2 N-m (20 lb-ft ±3 lb-ft).
Reinstall the belt routing idler and torque to 55 N-m ±8.3 N-m (40 lb-ft ±5 lb-ft).
NOTE: VERIFY THAT THE PULLEY IS CROWNED: F4TZ-8678-A.
Reinstall the vacuum pump and power steering pulleys so that the pulley hub is flush to the end of the shaft 0.00 ±0.10" (0.00 ±0.25 cm). Use Steering Pump Pulley Replacer T65P-3A733-C.
Verify assembly sequence of Navistar shims (E3TZ-6B306-A) 0.090" (2.3mm) at crankshaft-water pump pulleys, refer to Figure 2. The preferred assembly is with a pulley ring (E3TZ-6B306-A) in front and in back of the crank pulley and the spacer plate in front of the water pump pulley, only. Tighten to 32.5 N-m ±3 N-m (24 lb-ft ±2 lb-ft).
Install the new rubber-backed belt (F4TZ-8620-T with 130 AMP generator; F4TZ-8620-L with 165 AMP L/N generator) according to the belt routing decal.
Loosely route the belt over all pulleys except the routing idler.Assure that the belt fits correctly in all grooved pulleys.
Swing the tensioner to the installed position and slip the belt over the routing idler.
Reinspect the belt fit on all pulleys.
Reinstall the fan/clutch and shroud using Fan Clutch Pulley Holder T83T-6312-A and Fan Clutch Nut Wrench T83T-6312-B.
Tighten clutch nut to 133 N-m ±20 N-m (98 lb-ft ±15 lb-ft).
Tighten the four (4) shroud bolts to 6.5 N-m ±1.5 N-m (5 lb-ft ±1 lb-ft).
Resecure the top water hose. Tighten to 3.73 N-m ±.61 N-m (33 lb-in ±5 lb-in).
Reinstall air intake tubes. Tighten to 9.0 N-m ±1.4 N-m (80 lb-in ±12 lb-in).
Service the coolant system.
FEAD ALIGNMENT PROCEDURE
Check water pump pulley diameter and fan clutch. The correct water pump pulley is stamped 1816349C1 on the front of the pulley under the reinforcing spacer. Some vehicles built from 8/93 through 11/93 had a smaller pulley that prevents the tensioner from operating in range. (Ref. ONP 93B34). Turbo fan clutches should have F3TA-HA stamped on the flat of the clutch nut. If you have an F4TA-HA, replace it with an F3TA-HA. Naturally aspirated should have F2TA-JA stamped on the flat of the clutch nut. NOTE: BIMETAL IS IN THE FRONT COVER NOTCH SO THAT IT IS OPERATIONAL. SYSTEMS WITH INOPERATIONAL BIMETALS ARE OVERSTRESSED.
Check that the belt is fully supported on the routing idler and tensioner idler. Changes in the belt tracking are made by adding crankshaft shims from Shim Kit (F2TZ-6B306-E) to the reinforcing plate to move the belt forward. Replacing the plate with shims moves the belt back as it enters the idler pulley. Ensure fan pulley spacer is mounted in front of the pulley, see Figure 1. NOTE: There is no plate behind the water pump pulley.
Both idler pulleys may adversely affect belt tracking if symmetrically worn. If the idler pulley diameter is less at one (1) edge than the other, replace it with a new Idler Pulley (YS-216).
To minimize recurrence, replace the belt with a rubber-backed belt (JK6-1118 for the 130 amp generator or JK6-1151-B for the ambulance prep package application [165A L/N Alt.]).
Check the generator bracket for mis-build. For vehicles with 130 amp generators: the prefix F3TA is visible on the bottom of the generator bracket on F-Series vehicles, F3UA is visible on the bottom of the generator bracket on Econoline vehicles. Refer to Figure 2.
F3TA parts are shorter than F3UA parts and rely on a fuel filter bracket to locate the generator correctly in the sheave. Incorrect combinations result in the belt mistracking at the A/C compressor.
Check the generator bracket for spacers. For vehicles with 165 amp L/N (Ambulance Prep Pkg.): E4TA for F-Series; E4UA for Econoline generator bracket. Additionally, three (3) spacers separate the bracket from the cylinder head or fuel filter bracket. They are the same for both applications.
Replace the spacers if missing. See Figure 2.
A stamped steel sub-bracket attaches in back of the mounting tab at the top of the generator. Verify that it is not in front of the generator mounting tab. Replace the sub-bracket if it was misinstalled.
Verify that the vacuum pump pulley hub is flush with the end of the pump shaft.