4r70w

[Mush-Hog]

I have a few Q's about the auto tranny in my 96 GT. 1st and 2nd feels like a real close ratio shift then 2nd to 3rd and 3rd to OD feels like it is a lot wider of a RPM drop than compared to 1 to 2 shift, is this normal for this particular tranny? I read in the search pages of how this is a "wide ratio" tranny. Help or suggestions appreciated.

ex 1st to 2nd 3500 rpms drop to 2800
2nd to 3rd 3200 rpm drop to 2000
3rd to od 2500 rpm to 1500

sound normal?

no tq conv. shudder either it locks up

 

[Flghtmstr1]

The reason it feels a lot "wider" is because the torque converter is probably locked during the 2-3 and is definitely locked during the 3-4 shift.

 

[CobraRed_96_GT]

The reason it feels a lot "wider" is because the torque converter is probably locked during the 2-3 and is definitely locked during the 3-4 shift.

Actually, the TC will lock up at part throttle (especially if stock TC) very quickly under part throttle. It wont be slipping/multiplying/using the stator in the top of 2nd under cruising throttle. But i see where you're coming from, and that'd make sense.

The reason for the "hanging" shift we get in 3-4 if the method of gear change it uses, which is a "band clutch" actuation that acts very rudimentary and basically stops the spinning motion (translating into neutral power delivery) changes gear, the releases. This is more or less what I saw the lay-out as when it was open. The other gears work with line pressure to hold clutch pakcs open using overlap to maintain a seamless more fluid transition that happens quciker and therefore less rpm drop.

The 4th gear should be locked out during full throttle for this reason, and at higher power levels the simple band design can break or twist int input stub shaft into licorice.

The 1-2 and 2-3 shifts use a accumulator piston and spring set-up for the pressure transition, and through the valve body are much more customizable. If you wish to firm up or quicken the 2-3 shift i recommend a new tune or an aftermarket valvebody or simply the Jmod.

 

[rickshaw]

fyi if you need to replace your TC, consider this mod that many auto guys here have done; http://www.crownvic.net/tech/4R70Wnotes.pdf

hope this helps.

 

[Greenscobie86]

Mine felt exactly the same way before I yanked it out for a T-45... So it is normal.

Sorry I haven't got any useful info to add to this thread...

 

[Mush-Hog]

Thanks for the input, it only does this under partial throttle. Under full throttle really feels like the 1-2 shift. Whats better a new valve body or a tuner? I really dont want to do the jerry mod i would rather just slap in a new valve body or tune it. Automatics are a pain to dig into.

 

[CobraRed_96_GT]

Thanks for the input, it only does this under partial throttle. Under full throttle really feels like the 1-2 shift. Whats better a new valve body or a tuner? I really dont want to do the jerry mod i would rather just slap in a new valve body or tune it. Automatics are a pain to dig into.

Jerry mod = same work of putting in new valvebody. Which doeesnt require dropping the trans, only the pan. Most aftermarket valvebodies make serious changes and are tailored for cars that see the track. A tuner would be best for you right now

 

[Mush-Hog]

A tuner it is then. Which would you recommend? Thanks for all the help.

 

[scupking]

A tuner it is then. Which would you recommend? Thanks for all the help.

Xcal 3

 

[Mush-Hog]

thanks for the help i will get an x cal.