Auto Shifting

[Stangdriver1119]

I apologize if this is a repost but I couldn't find anything when I used the search button to look for information on this. Anyways I know very little about the automatic transmissions in our stang specifically the 4R70W. I've already gotten the fact its bad to go from drive to neutral and rev and then slide it back to drive...so does the same concept apply if you downshift from drive to 2nd or from 2nd to first? Thanks

 

[ponysarepretty]

Yes it is bad to downshift with a stock automatic transmission.

 

[triggz]

The 99+ 4R70W is capable of handling downshifts. Downshifting does cause lots of heat though, so I advise against it without a cooler.

Youre right on neutral drops though, that can cause quick mechanical failure.

Taken from TCCoA articles by Jerry, lead designer of the ford autos.

Will manual shifting hurt my transmission?

Well, the answer is it depends. On any 1996 and newer 4R70w, you can do all the manual 1-2 and 2-1 shifts you want and not hurt anything. If it were older than a 1996, I'd shy away from manual 1-2s unless you've modified the main control. I would stay away from excessive manual 4-2s on all transmissions older than 1998. In 1998 the manual valve changed to allow the direct clutch to exhaust faster, resulting in less wear

 

[SVT32VDOHC]

I had a 00 GT in summer of 04 with 6,300 miles, yes 6,300!! That car was faster and shifter better just by leaving it in drive. The reason people like downshifting and manual shifting auto's is because they want to feel like they have a stick because sticks are faster. This is not always true. I good tune on adusting shift points on a 4R70W will out-perform any stick car and driver. Example..Lidio's Mach 1. That car runs consistent times, and I have witnessed that car walk all over many cars at the track. LEAVE IT IN "D"

 

[MYSLO4-6]

A quick question, I have a SCT switch chip that I have to have my local dyno shop tune for me. Is there any info on what I should have my tranny set to?? As far as shift points and line pressures. Car seems to shift fine until at low rpm the 3rd to O/D shift is jerky/clunks, not so much in WOT.

Any ideas or suggestions??

Thanks Phil

 

[03ghoststang]

well if you do any WOT shifts into O/D that can damage the O/D band and cause it to shift weird i wouldn't recommend doing any WOT shifts into O/D.

 

[02LaserRed2V]

The only time I ever "manually" shift is downshifting from 3rd to 2nd whenever I'm accelerating/racing from a roll. That eliminates the 1/2-1 second delay when stepping on it. I've also done the drop to neutral to rev a billion times since getting my stang over 3 years ago. My auto is now starting to act a bit sloppy on the 2nd to 3rd gear shifting, but I think much of that has to do with me overly beating on it since getting the KB installed.

Based on butt dyno, manuals do "feel" a lot faster than an auto, especially when comparing stock versus stock. That's another reason why many get the impression a 5-speed is much faster than an auto when it's only marginally (about +.2 in the 1/4) faster.

 

[MYSLO4-6]

I shouldn't have said WOT but it shifts fine under throttle (normal highway driving). I concern is the low rpm or just letting of the throttle clunkiness/jerky of 3rd to O/D at lower speeds

Any ideas??

 

[ponysarepretty]

I think they are all a bit roughon the 3rd to OD shift, just by nature of what happens.

 

[Gearbanger 101]

I shouldn't have said WOT but it shifts fine under throttle (normal highway driving). I concern is the low rpm or just letting of the throttle clunkiness/jerky of 3rd to O/D at lower speeds

Any ideas??

Are you guys sure that the O/D shift you are feeling, isn't actually the feeling of the stock torque converter locking up? Some 4R70W's tend to expereince a "shudder" during lock up. Most of the later model ones have been cured of this, but I've still been told it happens on occasion.

 

[Gearbanger 101]

Here....this is what I was referring to.

Torque Converter Shudder (see TSB#98-8-7)

Symptom?
While the converter clutch is locking up, it feels like you just drove over rumble trips or train tracks. This will start to happen on 3-4 shifts only, when make it’s way to 2-3 shifts and when tipping it from closed throttle.
What Models?
All AODE’s and 4R70W’s. The 1998 and beyond vehicles may still get this, but if would be at much higher mileage’s than the 1997 and prior vehicles.
Problem?
No matter what year the vehicle, the problem is caused by a breakdown of the oil/friction material interface. Several different things cause this breakdown. The oil/friction interface getting too hot is the main reason.
Solution?
Depending on the model year of the vehicle, the problem is resolved different ways. Any vehicle that has shudder needs an additional transmission oil cooler. This will help keep the temperatures down. In addition, the vehicle needs Mercon V fluid. This is a new fluid that is currently available only at a dealer. Finally, 1996 and 1997 model year vehicles (except Mustang) need a different calibration in the EEC. This is available through a dealer.

 

[MYSLO4-6]

Thank you Gearbanger for the info, the only problem is that I had a PI torque converter not stock?? does this play a role in my problem?? plus I do not have a tranny cooler yet. please read my sig.

Thanks Phil

 

[Gearbanger 101]

My guess is that the use of the converter around town without an additional transmission cooler is heating the transmission fluid up to the point, that it’s breaking down and not doing its job properly. Tell me, has it been doing it for a while and do you notice this all the time, or just after driving for a while that it would give the transmission fluid time to really heat up?

If it's now doing it all of the time, it probably wouldn't hurt to flush the system of the old fluid and add a heavy duty transmission cooler to see what it does. Even if it’s not the problem, it's not going to hurt things any and probably should have been done right from the get go anyway.

 

[MYSLO4-6]

Its doing it all the time but does get worse as it heats up though, I guess I need a flush and filter. They do have filters right?? Is mercon V a HD fluid to use or use something a little better?? I'm going to add a cooler very soon because i'm talking to you on another thread too. I'm also thinking about ordering the FRPP auto trans oil pan that has fins on it, what are your thoughts on that??

 

[Gearbanger 101]

Its doing it all the time but does get worse as it heats up though, I guess I need a flush and filter. They do have filters right?? Is mercon V a HD fluid to use or use something a little better?? I'm going to add a cooler very soon because i'm talking to you on another thread too. I'm also thinking about ordering the FRPP auto trans oil pan that has fins on it, what are your thoughts on that??

Yes, they have filters and a filter flush would be a great idea. The aluminum FRPP finned pan couldn't hurt. It will help dissipate heat as well. Anything that lowers/regulates heat is a good idea.

 

[MYSLO4-6]

Thanks for the info!!!!