Ford Overdrive Transmissions 101

  • Published on
    29-Nov-2014

  • View
    3.074

  • Download
    7

Embed Size (px)

Transcript

<p>Ford Overdrive Transmissions 101ContentsIntroduction ...................................................................................................................................................................... 3 What is an AOD? ........................................................................................................................................................... 3 What is an AODE? ......................................................................................................................................................... 3 What is a 4R70W? ......................................................................................................................................................... 3 Definition of Terms ....................................................................................................................................................... 3 Differences within the 4R70W and AODE Family ............................................................................................................. 4 Torque Converters and Flexplates ................................................................................................................................ 4 Cases ............................................................................................................................................................................. 6 Main Transmission Connector ...................................................................................................................................... 6 Manual Lever Position Sensor (M.L.P.S.) ...................................................................................................................... 6 Shifter Pattern ............................................................................................................................................................... 6 Transmission Operation. ................................................................................................................................................... 6 How the Main Control - or Valve Body Works .............................................................................................................. 8 Common Problems.......................................................................................................................................................... 10 Transmission Do's, Don'ts, and FAQ's ............................................................................................................................. 13 Should I adjust the screw on the back of the EPC solenoid? ...................................................................................... 13 I hear a buzzing from my transmission, what is this? ................................................................................................. 13 Should I put on an additional transmission cooler? ................................................................................................... 13 Is there anything else I need to do when my transmission fails? ............................................................................... 14 How often should I change the transmission oil? ....................................................................................................... 14 What's the best way to change my transmission fluid? ............................................................................................. 14 What transmission fluid should I use? ........................................................................................................................ 14 A lot of shift kits, or articles, recommend drilling a hole in the valve body, should I do this? ................................... 14 Should I use a Kevlar band? ........................................................................................................................................ 15 What is better, a lockup torque converter or a non-lockup? ..................................................................................... 15 Do I need to change the PCM if I change the main control? ...................................................................................... 15 Why does my engine hit the rev limiter when I changed rear end gear ratios? ........................................................ 15 What about synthetic transmission fluid? .................................................................................................................. 16 Do police cars have better parts in the transmission? ............................................................................................... 16 Can I put a later model transmission in my car?......................................................................................................... 16 How much power can a 4R70W withstand? ............................................................................................................... 16 Will manual shifting hurt my transmission? ............................................................................................................... 16 Do I need a custom chip? ............................................................................................................................................ 17</p> <p>Building a Bullet Proof 4R70W ........................................................................................................................................ 17 Output Shaft................................................................................................................................................................ 17 Planetary Gear Set ...................................................................................................................................................... 19 Direct Clutch................................................................................................................................................................ 19 Forward Clutch ............................................................................................................................................................ 23 Reverse Clutch Cylinder and Intermediate One Way Clutch ...................................................................................... 26 Intermediate Clutch .................................................................................................................................................... 26 Stub Shaft (AODE and 4R70W only) ............................................................................................................................ 28 Stator Support ............................................................................................................................................................. 28 Overdrive Servo Assembly (AODE and 4R70W only) .................................................................................................. 29 Overdrive Band ........................................................................................................................................................... 30 Pressure Control Solenoid (AODE and 4R70W only) .................................................................................................. 30 Oil Pan and Filter (AODE and 4R70W only) ................................................................................................................. 31 Accumulators (AODE and 4R70W only) ...................................................................................................................... 31 Extension Housing ....................................................................................................................................................... 31 Reverse Servo.............................................................................................................................................................. 33 Case ............................................................................................................................................................................. 33 Other notes ................................................................................................................................................................. 34 Final Comments/Thoughts .......................................................................................................................................... 34 Modifying the Main Control............................................................................................................................................ 34 2-3 &amp; 3-2 shifts ............................................................................................................................................................ 36 4.6L T-Bird only ........................................................................................................................................................... 37 3-4 Upshift, 4-3 Downshift and Engagements ............................................................................................................ 37 Reverse Engagement .................................................................................................................................................. 39 Separator Plate Details ............................................................................................................................................... 40 Diagnosing Transmission Problems ................................................................................................................................ 43 Re-Wiring Your Vehicle for A Later Model Transmission ................................................................................................ 45 Final Thoughts/Wrap-up ............................................................................................................................................. 46 Driveline Critical Speed ................................................................................................................................................... 47 What it does - .............................................................................................................................................................. 47 Some detail - ............................................................................................................................................................... 47 Here are the Drill Specifications for the Separator Plate depending on the Horsepower you are using ....................... 51 1994 Mild, 300 HP or 300-450 HP Drill Specs and Part #s .......................................................................................... 51 1995 Mild, 300 HP or 300-450 HP Drill Specs and Part #s .......................................................................................... 52 1996 Mild, 300 HP or 300-450 HP Drill Specs and Part #s .......................................................................................... 53 1997 Mild, 300 HP or 300-450 HP Drill Specs and Part #s .......................................................................................... 54</p> <p>IntroductionThe automatic transmission is one of the most mis-understood, or just unknown, parts of today's cars. What I intend to do in this article is to go through some of the history, basic function, common problems, how to modify AOD, AODE, &amp; 4R70W Ford Automatic transmissions, and how to diagnose problems. The latter two transmissions, the AODE and 4R70W, are derivatives of the AOD. I will not cover items related to trucks, there is a lot of complexity with the trucks (you can have two trucks with the same engine and two different transmissions, the 4R70W and the E4OD) and is beyond what the scope of this is intended. In addition to the transmission detail, I will briefly discuss driveline critical speed and what that is. The first thing to do is to explain what the differences are among these three transmissions.</p> <p>What is an AOD?The AOD was produced from the 1980 model year through the 1993 model year. It went into a lot of different cars and trucks. It is a fully hydraulic transmission. This means that it had no electronic controls at all. It was completely controlled via hydraulics. The two inputs that control the transmission are throttle valve (or TV) pressure and governor pressure off the output shaft. The TV pressure is controlled by a cable (or rod if it's old) that goes up to the throttle body (or carburettor if you have one of those). It had a 1st gear ratio of 2.40, 2nd gear ratio of 1.47, 3rd gear ratio of 1:1, and 4th gear ratio of 0.67. The torque converter in the AOD is mechanically locked in 3rd and 4th gear. The only way to change this is a different input shaft that will then leave the converter open all the time. My intent is not to spend a lot of time talking about the AOD transmission, just to make you aware of what it is.</p> <p>What is an AODE?The AODE transmission came out in 1992. It was produced from the 1992 model year through the 1995 model year. The AODE only came in the following vehicles; 1992-1994 Town Car, Crown Victoria and Grand Marquis and the 1994-1995 Mustang (both the 3.8L V6 and the 5.0L V8). These are the only years and vehicles the AODE was ever produced. The AODE is an electronically controlled transmission. The shift schedule, pressure schedule and torque converter clutch control are controlled electronically through the EEC. The gear ratios of the AODE are identical to those of the AOD, 2.40, 1.47, 1, 0.67. Its electrical connector at the passenger rear of the case easily identifies this transmission.</p> <p>What is a 4R70W?The 4R70W transmission came out in 1993 and is still produced today. All Mark 8's came with a 4R70W, all 1994-1997 T-Birds came with a 4R70W, all 1996 to present Mustangs came with a 4R70W, all Town Cars, Crown Vic's and Grand Marquis from 1995 -present came with a 4R70W and a lot of trucks from 1994present also came with the 4R70W. There are only three differences between the AODE and 4R70W. The first is that it has a different gear set, a Wide ratio gear set, hence this is where the W came from. The gear ratios in the 4R70W are 2.84 for 1st gear, 1.55 for 2nd gear 1:1 for 3rd gear and 0.7 for 4th gear. The only other differences between the AODE and 4R70W is that the 4R70W uses a larger outside diameter slip yoke on the driveshaft which requires a different extension housing for this larger diameter and the 4R70W uses a better output shaft material. This is because of the higher torque multiplication of the lower 1st gear ratio.</p> <p>Definition of TermsBefore we get too far into this, I want to define some terms that will/may be used. EPC or VFS - This stands for Electronic Pressure Control solenoid or Variable Force Solenoid. This solenoid acts on the main regulator...</p>

Recommended

View more >