New 4.56 gears installed!

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BigGreenBronco

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After nearly two years of procrastinating i finally changed the gears in my bronco. I ordered the 4.56 gear kit from jegs. At first I thought that 4.56 would be to low but it is just right the engine can spin those 35 inch tires finally and i can hold overdrive..

 

miesk5

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yo,

Thanks for the review!

After you installed the 35 inch tires, did you re-calibrate the Programmable Speedometer Odometer Module (PSOM)?

If not, I have some re-cal LINKs in my site @ http://www.broncolinks.com/index.php?index=651

Including;

92-96; "...1. Check whether the conversion constant in the speedometer is correct with the following procedure: Press and hold the RESET button on the front of the speedometer while turning the key to RUN. Release the RESET button. The pointer will prove out and some codes will appear on the odometer display. If an "E" is on the left side of the display, the module is programmed for English display mode and should have English graphics (mph). A lower case "o" signifies an overseas (metric) graphics (kph). Verify the graphics and display modes agree. (The number appearing after the type is the microprocessor revision level and is not used in this test.) Rress and release the RESET button again. The conversion constant and the word CAL will be shown on the odometer display. Check the conversion constant shown on the odometer display with the chart below and verify the correct constant is entered. Turn off the key to exit this test. 2. Reprogram speed conversion constant using the following procedure: Locate the dealer mode programming enable single-terminal connector. The connector is located at the bottom of the instrument panel below the center of the glove box. On all vehicles, the dealer mode enable wire is Circuit #567 (LB/Y); DSCN0749.jpg here is the PSOM connector from under the dash, notice the flat pin in the connector, pic by jslax[/url]; Insert metal clip in service wire panel connector. Clip other end to vehicle ground while the key is in the OFF position. Turn key to RUN (not crank) position while holding down the trip odometer RESET button on speedometer. Release RESET button. Speedometer will prove out (sweep across dial and back). The English/Metric and revision levels will be displayed. The last number of the display is the dealer mode programming lockout count. This count shows the number of allowable conversion constant changes remaining. When the count is zero (0), no additional changes can be made to this instrument cluster. If a conversion constant change is required, a service instrument cluster must be ordered. Refer to this section for ordering information. Press and release RESET button again and PSOM conversion constant (without the decimal point) followed by the word CAL. Press and release the odometer SELECT button as many times as necessary to change conversion constant to the correct value. NOTE: Pressing and releasing the RESET button to lock in the new Conversion Constant reduces the number of times the PSOM can be reprogrammed by one count. The module can only be reprogrammed six times. If you change your mind and want to go back to the old conversion constant, turn the ignition switch off before you lock in the new constant. When the correct new value is displayed in odometer window, press and release the RESET button to lock in the new conversion constant. Turn the key off and remove the ground wire. Verify proper speedometer operation. To find conversion constants for tires with 15 inch rims that are not listed in chart, above multiply the revolutions per mile (at 45mph) of your tire times .0135. For 16 inch rims multiply by .015. The revs/mile can be found at your tire manufacturers web site. There are slight variations in revs/mile per tire manufacturers, but using one like the popular BFG A/T (see below) will get you very close. Example: BFG AT 33x12.50R15LT/C Revs/mile= 636 636 rev/mile X .0135 = 8.59 8.59 would be your conversion constant - Here is a listing of popular oversize BFG All-Terrain tires with conversion constants: Tire Size Revs/mile (at 45mph) Conversion Constant 30x9.50R15LT/C 705 9.52 31x10.50R15LT/C 677 9.14 32x11.50R15LT/C 656 8.86 33x12.50R15LT/C 636 8.59 35x12.50R15LT/C 599 8.09 " miesk5 NOTE;' this is the First known procedure available on the WWW

Source: by Benjamin Ratterree via miesk5 at Ford Bronco Zone Forums

 
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BigGreenBronco

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ok i found that my cal is 918 it should be 809 where do plug this psom wire i dont see anything that plugs into it and it is too short to reach anything is it the one on the passanger side?

 

Bebop Man

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You take some alligator clips, clip one end to plug, the other goes to a metal ***** on the chassis to ground out the circuit

here is the PSOM connector from under the dash, notice the flat pin in the connector. Insert metal clip in service wire panel connector. Clip other end to vehicle ground while the key is in the OFF position.
 

miesk5

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yo,

Thanks Bebopman for stepping up on this.

BIGGREEN, that 918 was for P265/75R15 size tires, so apparently no one prev to you has touched this.

and in TSB Ford advuses;

"PSOM Conversion Constants for 92-96 Bronco & F Series

TSB 94-16-16 Speedometer Re-Calibration

Publication Date: 10 AUG 1994

ISSUE: Some vehicles may have the Programmable Speedometer Odometer Module (PSOM) re-calibrated for a tire/axle combination that is not approved by Ford Motor Company/Ford Electronics Division.

ACTION: Refer to the appropriate Service Manual Section in the following chart for a comprehensive list of Ford Motor Company/Ford Electronics Division approved tire/axle combinations.

NOTE: FORD MOTOR COMPANY DOES NOT APPROVE OF THE USE OF ANY CONVERSION CONSTANTS OR TIRE/AXLE COMBINATIONS NOT LISTED IN THE CHARTS. RE-CALIBRATION OF THE PSOM'S CONVERSION CONSTANT MAY BE REQUIRED DUE TO A TIRE/AXLE CHANGE (NOT COVERED UNDER MANUFACTURER'S WARRANTY). THE CONVERSION CONSTANT IS A "NUMBER" USED BY THE PSOM TO SCALE OR INTERPRET THE PULSES PER MILE SENT FROM THE SPEED SENSOR SO THAT THE PSOM WILL RETAIN THE FACTORY SET ACCURACY. THE CONVERSION CONSTANT CAN BE CHANGED A MAXIMUM OF THREE (3) TIMES FOR THE 1992 MODEL YEAR VEHICLES AND A TOTAL OF SIX (6) TIMES FOR THE 1993-94 MODEL YEAR VEHICLES.

96psomconvconstants.gif

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Information Only"

========

Upper case is by Ford, not me

 
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BigGreenBronco

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thanks guys i have 35 by 12.5 with 15 inch rims i programmed the cal to 809. Unfortunatly im having another problem, yesterday i was playing around spinning the tires in the dirt and i went to fill up with gas when i get back i go to burnout and it wont at all my freind thinks its the weight from the gas but there is all a trans fluid leak could this have somthing to do with it?

 

Krafty

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I would look at your transmission cooler lines that run into the front of the rad for the source of the leak, and yes low trans fluid will cause slipping.

 
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