Automatic transmission problems

  • Sponsors (?)


00BlackBeautyGT said:
Hey I have a auto too. I don't understand what is meant with overdrive. Is it the O/D button right next to the handle?

Hummm... not sure i understand your question. The symptoms are present only while cruising in OD at around 40-50. That means the button next to the handle in active overdrive position " OD on ".
 
00BlackBeautyGT:

OD [or overdrive] means the gear ratio is less than 1.0 and is designed to provide improved fuel economy at cruising (i.e.--low torque demand). That is, the output shaft of the transmission (that is connected to the driveshaft) will be running at a higher rpm than the engine. Please take a look at the "Transmissions 101" articles at TCCoA.com for the specific ratios and an explanation of the evolution of the 4R70W transmission (AOD, AODE, 4R70W). These chapters are a 'must read' for anyone who drives an auto.

Chris
 
OD is an extra(overdrive) gear that gets you better gas milage and efficiency at cruising speeds. stop and go driving shouldnt use the od gear too much. the exhaust prolly sounds better b/c the rpms drop when the od gear kicks in. im no expert though.
 
94DanStang:

"speed545" is right about the "Transmissions 101" articles (Tech Articles/Transmissions section of TCCoA.com). There you will find how to do the "jerry mod": much quicker shifts by modifying the separator plate only. The trans is pretty solid but the OD band is the weakest link. WOT 3-4 shifts (i.e.--leaving OD on and stomping the gas) can cause premature death of the band. Transmissions 101 will explain all.

For the immediate problem, a complete draining of the trans (including torque converter), new filter, and fresh Mercon V should make things much better. Add an auxillary cooler to reduce heat and your transmission should last a long time.

speed545: "... like a dog" means it is very slow/sluggish. The j-mod will sharpen up the shifts so that the transmission will shift like a pit bull! Keep warm up north.

Gents, thanks I searched the 101 articles. I'll read further. Just bought my son a 2001 GT rag top. 90K miles but in god shape. What is the fluid capacity of the trans flush including the Torque Converter? I will replace the filter of course. I may go for the trans cooler as well. !Thanks!! Boaf
 
Boaf 32:

Sorry for the tardy reply. Transmission and converter should tak 12 to 13 quarts. Fill up with 10 quarts and start the engine and, with the brake pedal pushed down (hard), run the gear selector from P to 1, pausing to feel the transmission engage in each gear. Put the selector back in P and set the emergency brake. Check the transmission fluid level. This can be tricky so read the Owner Manual about the cold trans fluid level checking procedure. I used to have to read the stick half a dozen times to get a proper reading. Use a lint-free cloth to wipe the dipstick, too. Add 1/4 of a quart (1/2 a pint) at a time until you get the correct level. If you overfill the transmission, the ATF will froth and give you some shifting problems in addition to burping out of a vent and soiling the garage floor.

Use Mercon V ONLY for the 4R70W transmission. Mercon III is NOT to be used.

HTH,

Chris
 
Boaf 32:

Sorry for the tardy reply. Transmission and converter should tak 12 to 13 quarts. Fill up with 10 quarts and start the engine and, with the brake pedal pushed down (hard), run the gear selector from P to 1, pausing to feel the transmission engage in each gear. Put the selector back in P and set the emergency brake. Check the transmission fluid level. This can be tricky so read the Owner Manual about the cold trans fluid level checking procedure. I used to have to read the stick half a dozen times to get a proper reading. Use a lint-free cloth to wipe the dipstick, too. Add 1/4 of a quart (1/2 a pint) at a time until you get the correct level. If you overfill the transmission, the ATF will froth and give you some shifting problems in addition to burping out of a vent and soiling the garage floor.

Use Mercon V ONLY for the 4R70W transmission. Mercon III is NOT to be used.

HTH,

Chris
This is my sons Mustang (first car) and of course you want it to be right. Replaced the fluid and everything appears to be spot on: shifting well, no shuddering. Thanks. It was the first time in 90 miles this vehicle had it's fluid changed (found the factory plug for the transmission dip stick still in the bottom. Surprisingly, no bits of metal in the fluid. Thanks Chris.

Bob:pop:
 
Bob,

Glad to hear all went well. There's a donut-shaped magnet that should be cleaned, too, and it holds the nasty bits. Usually, the magnet has grey, sludgy fur on it and brake cleaner (keep it away from the paint and your lungs) takes care of it nicely.

The 4R70W is pretty durable. WOT 3-4 shifts (3 to overdrive) are a big no-no. 4-3 and 4-2 shifts are not healthy for the transmission either but Transmissions 101 will tell you much more.

I hope your son enjoys his Mustang. He's a lucky lad to have a cool ride as a first car!

Chris
 
Whatsup guys, I've been working on an 02 Mustang GT automatic (4R70W) that I bought about a a month ago. Finally started her up and took her for a drive only to find that the speedometer wasn't working, the transmission would it shift out of 1st gear, and the distance driven wasn't being accounted for on the odometer... any ideas on what could be wrong???
 
The automatic transmissions on the Mustang GT are really problematic. There is a large post here on this website about other people who own the Gt who are also having problems with their transmissions. Try to find it and read it. Also, I think that you made a BIG mistake by buying an automatic transmission in a Mustang GT. A manual 5 speed transmission would have been a better choice. They last longer and have less problems than the automatics.

You need to pull your head out of your a$$! I bought my 03 gt 5speed new and as we speak , a 4r70w is being built for it because the 5spd sucks! I have been on this site for 13 years and have read some stupid crap, but this is nuts!
 
Whatsup guys, I've been working on an 02 Mustang GT automatic (4R70W) that I bought about a a month ago. Finally started her up and took her for a drive only to find that the speedometer wasn't working, the transmission would it shift out of 1st gear, and the distance driven wasn't being accounted for on the odometer... any ideas on what could be wrong???
Check to see if the vss or oss are unplugged or broken, or the wiring is damaged. You may only have an oss, I know somewhere in the time frame they did away with the vss in the tail shaft. The oss is a two wire connector towards the rear of the transmission.