Torque Convertor Issue
Thread Starter
Advanced
Joined: Dec 2006
Posts: 93
Likes: 0
From: Omaha NE
Torque Convertor Issue
Hey guys need advice!!
My 1998 auto is acting up. From what I have gathered I am experiencing convertor chuggle or something of the like.
Seems like the convertor does not know when to lock up or unlock, down shift or not. It is not terrible, but enought to notice.
Mainly cruising at about 70 in OD and easing into a throttle depression, it will actually surge up 500 rpms, then down, then up...it is an issue.
I notice it also under just general driving conditions too.
I have a 3.42 diff that I want to install and I am looking for a 2600 stall convertor to pop up on the forum here, so I am reluctant to pay for a dyno tune.
Does anyone think that flushing the tranny would help this in the meantime?
Is there a particular solenoid that could be malfunctioning?
Any help would be great. I would hate to have to buy a new tranny when I just need a new convertor.
I have no tranny codes.
My 1998 auto is acting up. From what I have gathered I am experiencing convertor chuggle or something of the like.
Seems like the convertor does not know when to lock up or unlock, down shift or not. It is not terrible, but enought to notice.
Mainly cruising at about 70 in OD and easing into a throttle depression, it will actually surge up 500 rpms, then down, then up...it is an issue.
I notice it also under just general driving conditions too.
I have a 3.42 diff that I want to install and I am looking for a 2600 stall convertor to pop up on the forum here, so I am reluctant to pay for a dyno tune.
Does anyone think that flushing the tranny would help this in the meantime?
Is there a particular solenoid that could be malfunctioning?
Any help would be great. I would hate to have to buy a new tranny when I just need a new convertor.
I have no tranny codes.
Melting Slicks
Joined: Sep 2006
Posts: 2,041
Likes: 4
From: Rockford Illinois
Hey guys need advice!!
My 1998 auto is acting up. From what I have gathered I am experiencing convertor chuggle or something of the like.
Seems like the convertor does not know when to lock up or unlock, down shift or not. It is not terrible, but enought to notice.
Mainly cruising at about 70 in OD and easing into a throttle depression, it will actually surge up 500 rpms, then down, then up...it is an issue.
I notice it also under just general driving conditions too.
I have a 3.42 diff that I want to install and I am looking for a 2600 stall convertor to pop up on the forum here, so I am reluctant to pay for a dyno tune.
Does anyone think that flushing the tranny would help this in the meantime?
Is there a particular solenoid that could be malfunctioning?
Any help would be great. I would hate to have to buy a new tranny when I just need a new convertor.
I have no tranny codes.
My 1998 auto is acting up. From what I have gathered I am experiencing convertor chuggle or something of the like.
Seems like the convertor does not know when to lock up or unlock, down shift or not. It is not terrible, but enought to notice.
Mainly cruising at about 70 in OD and easing into a throttle depression, it will actually surge up 500 rpms, then down, then up...it is an issue.
I notice it also under just general driving conditions too.
I have a 3.42 diff that I want to install and I am looking for a 2600 stall convertor to pop up on the forum here, so I am reluctant to pay for a dyno tune.
Does anyone think that flushing the tranny would help this in the meantime?
Is there a particular solenoid that could be malfunctioning?
Any help would be great. I would hate to have to buy a new tranny when I just need a new convertor.
I have no tranny codes.
Dig
Joined: Jan 2006
Posts: 5,458
Likes: 1,120
From: Port Saint Lucie FLORIDA & HONDURAS
i agree.
also, if the trans is starting to shift hard after it is locking and unlocking ( trans applying full line pressure ) watch out and put a new converter in asap !! it has happened to me twice on my c5.
watch your trans temp too.
good luck
also, if the trans is starting to shift hard after it is locking and unlocking ( trans applying full line pressure ) watch out and put a new converter in asap !! it has happened to me twice on my c5.
watch your trans temp too.
good luck
Thread Starter
Advanced
Joined: Dec 2006
Posts: 93
Likes: 0
From: Omaha NE
Thanks guys
Now here is the question:
I have a 3.42 I want to put in.
should I just buy a performance convertor? 2600 stall and do it all at once?
Get a stock new convertor?
how much am I looking for stock new convertor with install?
I have a 3.42 I want to put in.
should I just buy a performance convertor? 2600 stall and do it all at once?
Get a stock new convertor?
how much am I looking for stock new convertor with install?
Drifting
Joined: Jan 2005
Posts: 1,556
Likes: 276
From: Marshall Texas
Drifting
Joined: Jan 2005
Posts: 1,556
Likes: 276
From: Marshall Texas
Drifting
Joined: Jul 2002
Posts: 1,484
Likes: 0
From: Morgan Hill Ca.
I just finished a complete install of a PI2600 Stall TQ verter, RPM tranny and 3:42 gear set on my 98. Wow! really woke her up! I am trying to figure out if I want to reprogram the shift points.
So far I am really happy with the change. I had 130K+ miles with a lot of autocross and racing. The stock rear end was a 2:73. The stock tranny was on its's last legs.
At cruise she is great. I am still getting used to it and find it harder to predict when she will shift when not running WOT. under WOT I know exactly when she will shift. under normal traffic conditions it does feel looser, but then I hear that is pretty normal for a 2600 stall.
So far I am really happy with the change. I had 130K+ miles with a lot of autocross and racing. The stock rear end was a 2:73. The stock tranny was on its's last legs.
At cruise she is great. I am still getting used to it and find it harder to predict when she will shift when not running WOT. under WOT I know exactly when she will shift. under normal traffic conditions it does feel looser, but then I hear that is pretty normal for a 2600 stall.
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Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
As for your tranny "hunting for gears" issue it is pretty common with a stock tune. You should program your PT shift points higher to prevent the hunting---Also make the split between the upshift MPH and the downshift MPH greater--Another thing I always do is to delete the TCC lock-up in 3rd entirely--I really see no reason for a TCC lockup there--only in 4th for freeway cruising.Hvaing the TCC lockup around town when driving 30 MPH is not saving fuel--is harder on your trans-makes it run hotter and more suspect for pinging.
Thread Starter
Advanced
Joined: Dec 2006
Posts: 93
Likes: 0
From: Omaha NE
ok sounds like some of this just may be normal for my tranny with 93k miles.
Thanks for the advice on the tranny tuning, but is taking it to a dyno shop my best option for the tuning you have suggested?
Seems like if I install the 3.42 I will need to take it to the dyno anyway to reprogram the pcm for the new gears.
Thanks for the advice on the tranny tuning, but is taking it to a dyno shop my best option for the tuning you have suggested?
Seems like if I install the 3.42 I will need to take it to the dyno anyway to reprogram the pcm for the new gears.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
As far as I know you won't have to re-program your speedo on a C5 as the vette has a trans-axle system and the speedo signal is at a different location than other vehicles--So it will be accurate when changing gears--as far as shift points go--the only way to tune those is by driving the car around at slow ,medium, and higher speeds--The dyno won't be of use for setting the points---You can guess and get them close but test driving it is the only way to get it how you want it
Drifting
Joined: Jul 2002
Posts: 1,484
Likes: 0
From: Morgan Hill Ca.
There is only one area that you would need to re-program for the gear set change. I don't know about the other tuner software but using HP Tuner Software under the heading speedometer you should change it to reflect the actual gear set you have.
Right now I am just driving around and keeping track of the speeds and shift points.
Your PCM actually works off the MPH and Throttle position %. For example at 25% TPS you will get a first to second shift at 14MPH and a second to third shift at 26MPH however: if your TPS is showing 37% you will get the first to second shift at 20 MPH and the second to third at 38MPH. The PCM works off of a set of tables for Normal Cruise and performance driving. Performance driving is essentially wide open throttle WOT and it will then shift of the RPM settings.
Right now I just reprogrammed the gear ratio in the speedo section and will make changes to the shift tables later to tailor it to my specific driving style.
Right now I am just driving around and keeping track of the speeds and shift points.
Your PCM actually works off the MPH and Throttle position %. For example at 25% TPS you will get a first to second shift at 14MPH and a second to third shift at 26MPH however: if your TPS is showing 37% you will get the first to second shift at 20 MPH and the second to third at 38MPH. The PCM works off of a set of tables for Normal Cruise and performance driving. Performance driving is essentially wide open throttle WOT and it will then shift of the RPM settings.
Right now I just reprogrammed the gear ratio in the speedo section and will make changes to the shift tables later to tailor it to my specific driving style.