Pulleys / Belts

Three different WP Pulleys were used on the 429 CJ/SCJ Mustang and 2 different WP pulleys on the 429 CJ Cougar.

This is the single groove water pump pulley for the CJ without A/C (Part # D0SE-8509-A) and is 6 1/2″ in diameter.

This is the 2 groove water pump pulley used on the CJ with A/C (Part #D0OE-8509-L). Note the larger diameter outer groove for A/C. The belt that goes in the outer groove lines up with the outer groove on the 3 groove crank pulley, the A/C Pulley, Fixed A/C Idler, and Adjustable A/C Idler. The inner groove is used by the belt that goes on the middle crank pulley groove and the P/S Pulley (or idler on a non-P/S car).

The SCJ also uses a 2 groove pulley (Part #D0OE- 8509-M), but the outer groove (5 3/4″ dia.), which drives the Smog Pump, has a smaller diameter than the inner groove (6 1/2″ dia.). Also, the outer groove has a narrower “V” groove for the narrower width v-belt used on the D0SE smog pump pulley. The inner groove is used by the belt that goes on the inner crank pulley groove (of the 2 groove crank pulley) and the P/S Pulley (or idler on a non-P/S car).

You might wonder why it is necessary to put an Idler on in place of the Power Steering (PS) Pump on the Non PS cars? The answer is to provide a tensioning method for the belt that drives the water pump! The water pump is driven by a belt that wraps the Crank Pulley, Water Pump (WP) Pulley and PS Pump Pulley. Belt tension was adjusted via the PS bracket on PS equipped cars. Without an adjuster of some type at the PS position, there would be no way to tension the belt between the WP and Crank Pulley. The Non Power Steering Idler, like the PS bracket, is also adjustable and is used to set belt tension. The pulley assembly part number is stamped number DOAE-8A617-B2 (service numbers D0AZ-8679-A or Motorcraft # YS-32) and the bracket stamped part number is DOAE-8A620-A (service numbers D0AZ-8680-A or Motorcraft # YS-43).

Installed views of P/S Idler

Two A/C Idlers were used together on the 429 CJ with Air Conditioning. An Adjustable Idler up next to the A/C compressor and a Fixed Idler that bolted to the P/S Bracket and Water Pump.

A/C Idler – Adjustable

This is the Adjustable A/C Idler. It was used to adjust belt tension on the A/C compressor. A square slot was placed in the bracket to allow a breaker bar to be inserted and levered by the mechanic to set belt tension. The factory part number from the MPC for this part is D0AZ-8678-C, however no stamped part number is visible on parts we have examined. Installed views of the Adjustable A/C Idler are shown below.

This is the Fixed A/C Idler that bolted to the Water pump and P/S bracket. We suspect this fixed idler was used to keep the belt from vibrating on the long span from the A/C Compressor to the Crank Pulley. The factory part number for this part is D0AZ- 8678-B, however, the service part seems to be far more common at swap meets. It has part number D3AH-8A617-AA as shown below left. An installed view of the Fixed Idler is shown below right.

Two different Crankshaft Pulleys were used on the 429 CJ and SCJ. The CJ w/o A/C and SCJ used a two groove version while the CJ with A/C used a three groove version.

This is the 2 groove Crank Pulley (Part #D0OE-6312-F) used on all SCJ and CJ without A/C.
The inner (rear) groove is 7.0″ diameter and the outer (front) groove is 6 1/4″ diameter.

This is the 3 Groove Crank Pulley (Part # D0OE- 6312-J) for use on the CJ with A/C.
Pulley Diameters; rear groove -7 1/16″, middle groove 6 1/4″, front groove 7 5/32″.

This is the Crank Dampener/Balancer used on both the 429 CJ and SCJ (Part #D0OE-6316-B2)
Balancer diameter: 6 21/32″.

This is the 3.05″ diameter stamped steel alternator pulley (Part #D1ZF-10A352-AA) used on all 429 CJ/SCJ 55 amp alternators.

This is the P/S Pulley (Part #D0AR-3D673-A) used on the 429 CJ/SCJ. It had a diameter of 5 5/8″.

This is Smog Pump Pulley (Part# D0SE-9C480-A) used on the SCJ Smog Pump. It had a 5 1/2″ diameter with a 15/32″ sheave.

Note To Our 429 CJ/SCJ Torino/Cyclone/Ranchero Friends: During the research for this page, it was noted that several of the pulley’s listed above for the 71 429 CJ/SCJ Mustang and Cougar had different part numbers/diameters than those listed for your 429 CJ/SCJ Torino/Cyclone/Ranchero applications. Please be aware of this when using this site and we recommend that you reference the MPC for the correct part numbers for your vehicles.

429 Group Member Cars at the Mustang 40th Anniversary

Jim Ginger’s 429 CJ Mach 1