Help! auto tranny problem late 1-2 shift

[Craiger77]

Here’s my problem:
I recently had 4:10 gears installed on my auto 2001 Gt. Along with the gears, I had a tranny cooler the J-mod done.

Everything was fine except I had to adjust the speedo and shift points with a handheld predator that came with the car when I bought it.

Here’s the issue – When I start from a slow roll (between 5-10mph) and go WOT, the 1-2 shift will not occur at the set rpm point (4600 rpm’s). It will hold the 1st gear until it hits the rev limiter for 1or 2 seconds and then shifts to 2nd. If I start from a complete stop, the 1-2 shift occurs at approx. 5400 rpm’s (indicating the 4600 rpm point is working well.)

The car didn’t do this before the gears and j-mod were installed. I’m worried that the j-mod got messed up somehow. I didn’t do the install. The guy who did the gears did both at the same time.
- I have done searches for the past month on all the mustang sites and tccoa.
-The fluid levels were checked and are good.
- The tranny fluid was changed when the j-mod was done. (Less than 500 miles ago)
- The car has obo 35k miles on it

Thanks in advance for your help guys.

 

[DBMSTNG]

the problem is not the Jmod. the problem is you adding the gears and not having the WOT shift points adjusted.

the way the shift points work is not like you are expecting. when you set the shift point at say 4600rpm, the transmission will not shift at 4600rpm. how it actually works is the transmission will start the process to shift at 4600rpm. the process takes about 1 to 1.5 seconds to complete. so if the rpm is accelerating at 1000rpm per second, you hit redline.

 

[Rickey_Bobby]

Lower the shift point.
The gears made it so the engine can spin up faster, and the tranny just cant shift fast enough.
I had the same problem when I added a s/c. The extra power made the tranny spin up faster.

 

[Stang|ess]

the problem is not the Jmod. the problem is you adding the gears and not having the WOT shift points adjusted.

the way the shift points work is not like you are expecting. when you set the shift point at say 4600rpm, the transmission will not shift at 4600rpm. how it actually works is the transmission will start the process to shift at 4600rpm. the process takes about 1 to 1.5 seconds to complete. so if the rpm is accelerating at 1000rpm per second, you hit redline.

If I start from a complete stop, the 1-2 shift occurs at approx. 5400 rpm’s (indicating the 4600 rpm point is working well.)

 

[Craiger77]

I understand that the ECU shift point needs to be set under the desired actual shift point. In fact, the tranny does shift correctly from a dead stop at approx 5400 RPM's (Ecu shift point 4600 rpm's)

The problem occurs when the I go WOT from a slow roll (obo 10mph). The car will kick down to 1st and spin up into the rev limiter, set at 6200 rpm's. It bounces the rev limiter obo. twice and then shifts to second.

I have considered bumping the shift point lower but then the car shifts too low from the dead stop.

What have you guys set your 1-2 shift points at?

Thanks

 

[Rickey_Bobby]

Increase your line pressure. This will make the shifts firmer as the clutches slip for a shorter period of time. Thus making the shift take less time and making your clutches last longer.
Or, do like I did.. give up and get a manual

 

[Craiger77]

Increase your line pressure. This will make the shifts firmer as the clutches slip for a shorter period of time. Thus making the shift take less time and making your clutches last longer.
Or, do like I did.. give up and get a manual

LOL A manual is a great idea. I've been dreaming of a TKO since I bought the car.

It's a long story but the short of it is, I had an 03 cobra that I had to sell to buy a house. Afterwards, The wife promised me another (but less expensive) Mustang and this is it. But the she-devil tricked me and said that it had to be an auto!!!

I'll try increasing the line pressure. But, I've always read that more line pressure is bad?

Thanks

 

[DBMSTNG]

I understand that the ECU shift point needs to be set under the desired actual shift point. In fact, the tranny does shift correctly from a dead stop at approx 5400 RPM's (Ecu shift point 4600 rpm's)

The problem occurs when the I go WOT from a slow roll (obo 10mph). The car will kick down to 1st and spin up into the rev limiter, set at 6200 rpm's. It bounces the rev limiter obo. twice and then shifts to second.

I have considered bumping the shift point lower but then the car shifts too low from the dead stop.

What have you guys set your 1-2 shift points at?

Thanks

you could change your 2-1 shiftpoint so that it does not kick down a gear if the increase in line pressure does not work. if you are just using a canned tune on a Predator or X cal, increase the pressure to the max. the tuner won't allow the pressure to go higher than the tranny can handle. with the J mod, it can handle more pressure than stock. the problem probably has to do with traction. look at mods to add traction and you can solve the problem that way as well.

 

[Craiger77]

Thanks for the suggestions guys. As soon as the rain stops, I'll try and see if the changes will work.

 

[rebelleader]

I'll try increasing the line pressure. But, I've always read that more line pressure is bad?

Thanks

After doing the J-Mod, you are supposed to bump the line pressure up all the way...

 

[Craiger77]

Ok, The weather has cleared up some and the roads have dried off.

I just got home from work and bumped the line pressure all the way up.

- Bad news, it is still not shifting from a slow roll as I described above. It seems the line pressure had little to no effect. I even bumped the rev limiter to 6300 rpm's but the motor still hits the limiter.

Any other suggestions??

Thanks again guys

 

[crod99]

I have basically the same issue and I have a custom tune only my car was ok untill I added the spray then I had trans issues in my tune the 1-2 shift is commanded at 4600 and happens at 6150 . the advise you have been given so far is correct . You can keep playing with the line pressures or you can simply just realize that these transmissions are very pickey and will not always work the way we would like . You can always go with a manual valve body and take away the auto feature all together . I guess the bottom line is this it takes the pcm 1-1.5 seconds to actually make the shift you command so if you want to shift it yourself you should make your shift as I do at 5000 on the motor and 4600 on the spray . My car shift perfect from a dead stop also and also hits the limiter from a roll . It does suck! I have found leaving it in drive helps on the gas but on the motor it shifts way to early so somewhere there has to be a happy medium . and here it is put the stock gear backin ! Chris I know I did not help at all but sometimes it feels good to vent !!!!!

 

[Rickey_Bobby]

I do auto to manual conversions
You are limited by the tranny you have.
There are 2 choices.

1. Built auto.
http://cgi.ebay.com/ebaymotors/ws/e...RK:MEWA:IT&viewitem=&item=160065768055&rd=1,1

Pretty easy for most people to install. Very straightfoward.

2. Swap it to a manual.
Very hard for most people. Many parts req'd. And now you can't blame the car for missed shifts anymore.

Remember, a built auto will out-shift any human in a drag race, but will suck in a road course. If your looking for fun-to-drive factor, I would suggest go with the manual.

If you want to know more about the swap process, send me a PM.

-Steve

 

[Craiger77]

Chris I know I did not help at all but sometimes it feels good to vent !!!!!

I've found everypost helpful. Part of the reason I posted my problem was because I literally searched a couple weeks on a number of mustang sites and could not find anybody with similar issues as me. Now that I know that others are having similar issues, I know that it isn't my particular tranny that is messed up... they all are!!

The car will never see a track or road course. Its a convertible that was bought for cruising and "some" spirited driving from time to time. It just bothers me that it doesn't work like I feel it should 100% of the time.

I think I will put a manual tranny in one day, unfortunately it isn't likely to happen soon.

 

[Rickey_Bobby]

you could try an aftermarket valve body and shifting it manually.
I know a few people that get around the late shift like that.

 

[san~man]

The chip I had burned years ago never gave me the problem you're experiencing, and I have almost the exact same mods as you do.

 

[ShapeShifter]

i kinda had the same problem...i had the gears installed,programmed the car with the predator and took it to the track,i kept hitting the rev limiter twice from 1-2nd gear....so it was shifting like chit and the speedo was way off aswell by like 10-12mph....so i sold the diablo and bought an XCal2 with a custom tune from VMP,no probs what so ever now!

 

[Craiger77]

I'm gonna take the car back to the installer.

The predator came with the car and honestly, I never cared for it that much. It just doesn't have all the options that I would like to have, especially for the auto.
From what I have read and seen people seem to be more happy with the Xcal2

 

[rebelleader]

From what I have read and seen people seem to be more happy with the Xcal2

I have an Auto and sold my Pred for an XCal2. Wish I still had the Pred. The Xcal is nowhere near as user friendly as the Pred.

 

[Duke309]

After doing the J-Mod, you are supposed to bump the line pressure up all the way...

My friend that has 3.73s, jmod and an xcal2 doesnt have the line pressure maxed out at all and its already really noticeable when it shifts in regular driving. How can you stand being jerked everytime it shifts with it maxed?