Transmission Issues

[rivetpro]

Ill modify mine inline with your. . I don't know what all that will improve because I've never modified my prior cars performance (except exaust and intake.). And my last car (CTS-v) had everything and needed nothing. And most of my cars have been manual trany.... 35 yrs old and This is my first automatic. Any upgrade to turn this rig into a manual shift?

Im an engineer but somewhat specialized in what i do.... Just not car transmissions, How would bills products improve the car, and are they precursor to super or turbo charges. That's what I really want to get.

[Mongoose9400]

Originally Posted by rivetpro

Ill modify mine inline with your. . I don't know what all that will improve because I've never modified my prior cars performance (except exaust and intake.). And my last car (CTS-v) had everything and needed nothing. And most of my cars have been manual trany.... 35 yrs old and This is my first automatic. Any upgrade to turn this rig into a manual shift?

Im an engineer but somewhat specialized in what i do.... Just not car transmissions, How would bills products improve the car, and are they precursor to super or turbo charges. That's what I really want to get.

From Bills Site:

Designed by using a fully operational, test NAG1 that monitored all clutch pressures, torque converter pressures, and torque converter lock up clutch pressures all with accurate analog gauges.

The Stage II modified valve body will increase the NAG1 shift pressures.

The more aggressively the NAG1 is driven, the firmer the shift.

The downshifts are firmer than stock also, but not to the point of being too harsh.

[A.V.GCSRT8]

Originally Posted by Mongoose9400

I'm thinking when I hit 30k miles I'll service the tranny, drop the pan and change the filter and top off with fresh fluid. When doing that throw a
Valve body in if they are good to go. Figure a year or so out on that. Currently a little of 15k miles on the rig.


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Thats my plan as well. Except mine will be a couple years out, I dont DD the Jeep since I commute to work

[hashem2013]

I have paid waiting delivery of my new GC SRT8 just before new year . been reading some threads about the current 5 speed transmission issues and that its not certified to handle the torque of the 6.4 SRT engine ?? bottom line : is it a reliable transmission ???

[hashem2013]

Originally Posted by meeper

i dunno why chrysler could think they would be able to use a transmission thats only rated for 428 ft lbs on a big heavy car with an engine making 470 ft lbs..... duRRRR

I am also asking same question also . can this 5 speed auto handle the 6.4 engine power ????

[Mongoose9400]

I don't know the internals of the NAG1 in the WK2, but I assume it's the same as the WK1. Granted its normally rated for a torque of 580 Nm, internals can be changed to allow more. Some Mercedes use the same tranny with different internals that allow up to 7xx Nm IIRC. There are also other variants of the NAG used by Merc.

On the other hand there is a lot of evidence here that the stock tranny can handle more power reliably on the WK1. I'm sure the level the WK2 operates at is in a safe parameter. They gave you a 100,000 mile warranty on it I'm betting they made sure it'll last. I got 20k hard miles on mine and so far so good. I wouldn't really worry about it.

Also, the full torque is available all the time. When it is all available, say like near the end of the gear and going to shift, torque management software handles it.

I'm no expert on it though, just my thoughts.


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[DrSheldonCooper]

Originally Posted by Kadonny

Ok, update on what I thought was the transmission. It's not the transmission, it's a throttle issue.

Had it happen 3 times recently and the past two were the worst. Doing about 45 mph on a country road, usually going uphill I give throttle to keep speed going up the hill. The problem is the engine does not recognize the throttle. The Jeep doesn't stall, it just doesn't take the increased throttle. Did it this morning, I slowly pushed the pedal down to accelerate with nothing happening. This lasted about 3 seconds when I finally almost got my foot to the floor the transmission does a real hard downshift and the throttle kicks in to jolt me back in my seat. From there it drives normally.

So, what the hell can this be? I'm taking it in again to fix the windshield, so for sure I'm going to be harping on this issue. Unacceptable.

these jeeps, like most newer vehicles don't use the traditional cable for controlling the throttle body. it uses a drive by wire design. that means there is a motor on the throttle body. when you press on the accelerator pedal, a signal is sent to your computer which in return controls the throttle body and opens it based on what it sees when you hit the accelerator pedal. if there is a dead spot in the throttle sensor or the pedal position sensor it will act just like a trans issue but isn't. it'll jerk n hesitate. all the dealer will do is a TPS sweep with a scanner connected to see the pattern it produces. should be a nice hill like pattern, but with a dead spot it'll dip to 0v and throw everything off tilt. hope this helps. i'm sure someone already explained it but i didn't read the whole thread.

[Kadonny]

Originally Posted by DrSheldonCooper

these jeeps, like most newer vehicles don't use the traditional cable for controlling the throttle body. it uses a drive by wire design. that means there is a motor on the throttle body. when you press on the accelerator pedal, a signal is sent to your computer which in return controls the throttle body and opens it based on what it sees when you hit the accelerator pedal. if there is a dead spot in the throttle sensor or the pedal position sensor it will act just like a trans issue but isn't. it'll jerk n hesitate. all the dealer will do is a TPS sweep with a scanner connected to see the pattern it produces. should be a nice hill like pattern, but with a dead spot it'll dip to 0v and throw everything off tilt. hope this helps. i'm sure someone already explained it but i didn't read the whole thread.

I think you hit the nail on the head. Going back to the start of this thread, I eventually had my accelerator pedal re-learned and the problem shifting went away. Almost 2 months now and it's been running great.

[Kadonny]

Damn it. Just the day I post above, it happened again. 2 months running perfect, not anymore.

[barish93]

Sorry to post in an old thread, but today i noticed that i was getting some bad slip from the trans. One time i was going up a hill and using the paddles and there was just no power for some reason. I downshifted all the way to 2 and was close to full throttle and i barely made it up the hill. After i stopped the car it acted fine for awhile. On my way home, a deer ran across the road, and i slammed on the brakes and when i pushed the accelerator down nothing happened for a good 2-3 seconds. I let off and went back on it again and it was all fine. Any suggestions on what to do.