Automatic trans problem
10-01-2012, 01:06 AM
#1
Thread Starter
Join Date: Sep 2012
Posts: 7
Automatic trans problem
2002 Mustang GT Auto trans. 109000 miles. My question is under full throttle the car is fine. Car pulls hard. Doesn't slip. On the highway car drives like a dream. When I'm cruising around 35,40,45 mph the car bucks, shudders. When you turn the OD off the car is better. Any ideas? Does the trans need to be rebuilt? Thanks for all your help. I miss my fox more and more now. Last commentators on the idle issue I was having. Thanks problem solved.
10-01-2012, 11:01 AM
#2
5th Gear Member
Join Date: May 2009
Location: kentucky
Posts: 2,241
this seems to be a problem in some of the 4r70w mustangs. mine does it too and i have just 64,000 on mine. i dug a little on finding info but didnt find anything solid. i beleive mine sharted sometime after i went in with a tuner and adjusted my line pressures. i'll do a little digging today and see what i find
10-01-2012, 11:07 AM
#3
5th Gear Member
Join Date: May 2009
Location: kentucky
Posts: 2,241
10-01-2012, 11:13 AM
#4
5th Gear Member
Join Date: May 2009
Location: kentucky
Posts: 2,241
4R70W
A revised version of the AODE was released in 1993 with the Lincoln Mark VIII. Compared to the AODE, it has lower 1st and 2nd gear ratios for better take-off acceleration and was designed for better gearset strength. On vehicles powered by a 5.4 L V8, a stronger gearset is used than in normal duty 4R70Ws. In 1998, due to durability concerns, the intermediate one-way roller clutch was replaced with a mechanical diode providing extra holding capacity and longer service.
While there is speculation that the 70 can be multiplied by 10 to indicate the ft-lbs of torque this transmission is capable of handling including torque converter multiplication, (i.e. 700 ft-lbs of torque), there is no reliable source indicating this. In fact a Ford document stated that the 2003 "Expedition's 4R70W transmission is rated to handle up to 506 foot-pounds of torque, which provides a large performance cushion beyond the peak torque rating of Expedition's largest available engine." http://media.ford.com/products/press...423&make_id=92 . It is more plausible that the number indicates the torque handling capability in N-m, as 506 ft-lbs converts to 686 N-m which could be rounded to 700 N-m. The "70" may also refer to the transmission's torque capacity after torque converter multiplication which occurs at low rpm's when the torque converter is more "elastic". 4R70W stands for 4 gears, Rearwheeldrive, 70 is a measurement of horsepower and Wide gear ratio compared to the AODE.
The gear ratios are: 1st: 2.84 :1 2nd: 1.55 :1 3rd: 1.00 :1 4th: 0.70 :1 Rev: 2.23 :1
Applications:
1993–1998 Lincoln Mark VIII
1993–2003 Ford F-Series
1994–1997 Ford Thunderbird
1995–2004 Ford Crown Victoria
1996–2001 Ford Explorer
1993–2004 Lincoln Town Car
1994–1997 Mercury Cougar
1995–2004 Mercury Grand Marquis
2003 Mercury Marauder
1997–2004 Ford Expedition
1997–2001 Mercury Mountaineer
1996–2004 Ford Mustang
[edit] 4R75W
In 2003 Ford revised the 4R70W transmission with a stronger ring gear that had 24 lugs, as opposed to 6, for the output shaft sensor (OSS) to read off of, a new torque converter, a revised front pump assembly, and a vehicle speed sensor (VSS) that compliments the OSS to improve shift quality and efficiency. These improvements allowed the 4R75W to handle more power while being more efficient and economical. While not used on all 2003 model year vehicles, the 4R75W/E transmissions eventually replaced the 4R70W/E.
Newer transmissions that are referred to as 4R70E or 4R75E have modifications that compliment Fords switching to throttle by wire. The PCM was given a more powerful microprocessor and Ford added a turbine speed sensor to the transmission. This allows the PCM to know the speed of the input shaft after the torque converter which is used in combination with crankshaft speed to detect the amount of slipping going on in the torque converter. This information provides PCM with the basis for fully electronic shift scheduling which limits "hunting" and fine-tunes shift speed and feel. It lets the PCM know what the torque will be in the next gear so it can choose the shift points based on the vehicle's projected performance in the next gear. Coupled with the electronic throttle strategy, the transmission computes the output torque required to maintain the vehicle speed, and chooses the correct gear and converter state accordingly.
[edit] Modification
The most practical modification for the 4R70W is the J-mod. It involves modifying the valve body separator plate and gaskets as well as changing or removing accumulator springs to alter the shift timing of the transmission. While these modifications can be done to 4R75W transmission, the results are not as dramatic as some of the details of the J-Mod (bigger holes in the separator plate and gasket) were done to the transmission in its design. These modifications are specified by one of the Ford engineers who designed the transmission. It offers faster engagement, quicker shifting, smoother operation, and increased service life. All parts can be bought at Ford dealers for less than $60 including the fluid.
A 20,000+ GVW cooler is highly recommended for all vehicles. Breakdown of the transmission fluid often results in "converter shudder" (feels like driving over rumble strips) where converter tries to maintain a steady slip rate during lock-up, but alternates between slipping and grabbing. Frequent fluid changes, especially when used for towing, are the single best method to prevent shudder. Shudder occurs because the torque converter never fully enters "lock-up", and ends up bouncing in and out of lock-up to slip. This causes the engine to flare up and then down again as the clutch cannot hold back the power of the engine.
A revised version of the AODE was released in 1993 with the Lincoln Mark VIII. Compared to the AODE, it has lower 1st and 2nd gear ratios for better take-off acceleration and was designed for better gearset strength. On vehicles powered by a 5.4 L V8, a stronger gearset is used than in normal duty 4R70Ws. In 1998, due to durability concerns, the intermediate one-way roller clutch was replaced with a mechanical diode providing extra holding capacity and longer service.
While there is speculation that the 70 can be multiplied by 10 to indicate the ft-lbs of torque this transmission is capable of handling including torque converter multiplication, (i.e. 700 ft-lbs of torque), there is no reliable source indicating this. In fact a Ford document stated that the 2003 "Expedition's 4R70W transmission is rated to handle up to 506 foot-pounds of torque, which provides a large performance cushion beyond the peak torque rating of Expedition's largest available engine." http://media.ford.com/products/press...423&make_id=92 . It is more plausible that the number indicates the torque handling capability in N-m, as 506 ft-lbs converts to 686 N-m which could be rounded to 700 N-m. The "70" may also refer to the transmission's torque capacity after torque converter multiplication which occurs at low rpm's when the torque converter is more "elastic". 4R70W stands for 4 gears, Rearwheeldrive, 70 is a measurement of horsepower and Wide gear ratio compared to the AODE.
The gear ratios are: 1st: 2.84 :1 2nd: 1.55 :1 3rd: 1.00 :1 4th: 0.70 :1 Rev: 2.23 :1
Applications:
1993–1998 Lincoln Mark VIII
1993–2003 Ford F-Series
1994–1997 Ford Thunderbird
1995–2004 Ford Crown Victoria
1996–2001 Ford Explorer
1993–2004 Lincoln Town Car
1994–1997 Mercury Cougar
1995–2004 Mercury Grand Marquis
2003 Mercury Marauder
1997–2004 Ford Expedition
1997–2001 Mercury Mountaineer
1996–2004 Ford Mustang
[edit] 4R75W
In 2003 Ford revised the 4R70W transmission with a stronger ring gear that had 24 lugs, as opposed to 6, for the output shaft sensor (OSS) to read off of, a new torque converter, a revised front pump assembly, and a vehicle speed sensor (VSS) that compliments the OSS to improve shift quality and efficiency. These improvements allowed the 4R75W to handle more power while being more efficient and economical. While not used on all 2003 model year vehicles, the 4R75W/E transmissions eventually replaced the 4R70W/E.
Newer transmissions that are referred to as 4R70E or 4R75E have modifications that compliment Fords switching to throttle by wire. The PCM was given a more powerful microprocessor and Ford added a turbine speed sensor to the transmission. This allows the PCM to know the speed of the input shaft after the torque converter which is used in combination with crankshaft speed to detect the amount of slipping going on in the torque converter. This information provides PCM with the basis for fully electronic shift scheduling which limits "hunting" and fine-tunes shift speed and feel. It lets the PCM know what the torque will be in the next gear so it can choose the shift points based on the vehicle's projected performance in the next gear. Coupled with the electronic throttle strategy, the transmission computes the output torque required to maintain the vehicle speed, and chooses the correct gear and converter state accordingly.
[edit] Modification
The most practical modification for the 4R70W is the J-mod. It involves modifying the valve body separator plate and gaskets as well as changing or removing accumulator springs to alter the shift timing of the transmission. While these modifications can be done to 4R75W transmission, the results are not as dramatic as some of the details of the J-Mod (bigger holes in the separator plate and gasket) were done to the transmission in its design. These modifications are specified by one of the Ford engineers who designed the transmission. It offers faster engagement, quicker shifting, smoother operation, and increased service life. All parts can be bought at Ford dealers for less than $60 including the fluid.
A 20,000+ GVW cooler is highly recommended for all vehicles. Breakdown of the transmission fluid often results in "converter shudder" (feels like driving over rumble strips) where converter tries to maintain a steady slip rate during lock-up, but alternates between slipping and grabbing. Frequent fluid changes, especially when used for towing, are the single best method to prevent shudder. Shudder occurs because the torque converter never fully enters "lock-up", and ends up bouncing in and out of lock-up to slip. This causes the engine to flare up and then down again as the clutch cannot hold back the power of the engine.
Last edited by school boy; 10-01-2012 at 11:15 AM.
10-02-2012, 07:08 PM
#7
3rd Gear Member
Join Date: Nov 2009
Location: AZ
Posts: 589
W/ 109,000 and it never being changed DO NOT FLUSH IT!!!! you hear tons of horror stories about flushes breaking grime, sludge, etc lose and it causing NEW problems, or trans failure. Change the fluid, put a new filter in. and while the pan is off, add a drain plug... IF the pan is off, you can drop the valve body fairly easily which will allow MORE fluid to come out, and than you can add more new fluid. I wouldnt flush it.
10-02-2012, 07:12 PM
#8
2nd Gear Member
Join Date: Sep 2008
Location: Utah
Posts: 155
Don't mean to hijack the thread, but does that mean my 03' has the 4R70W or the 4R75W?
The code under TR on my door panel data sticker is U, which as far as I can find is the 4R70W.
Been thinking of doing the J-mod at some point(Don't believe the fluid has ever been changed in 84k) but it sounds like its not really needed if you have the 4R75W, or would you guys do the J-mod either way?
The code under TR on my door panel data sticker is U, which as far as I can find is the 4R70W.
Been thinking of doing the J-mod at some point(Don't believe the fluid has ever been changed in 84k) but it sounds like its not really needed if you have the 4R75W, or would you guys do the J-mod either way?
Last edited by Fivaldrood; 10-02-2012 at 07:17 PM.
10-02-2012, 07:20 PM
#10
2nd Gear Member
Join Date: Sep 2008
Location: Utah
Posts: 155