2-3 shift clunk
#1
TECH Fanatic
Thread Starter
iTrader: (32)
Join Date: Oct 2005
Location: Fairfax, Virginia
Posts: 1,687
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I've had this problem for a long time and it's getting on my last nerve. Whenever the car shifts into 3rd gear, I get this clunk that I feel and hear. The same goes with downshifting 3-2. It will only do it with little or no throttle. Never from %50-WOT. Whats going on?
#2
TECH Addict
iTrader: (3)
Join Date: Nov 2005
Location: Lincoln, NE
Posts: 2,869
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hey join the club:
https://ls1tech.com/forums/showthrea...ivetrain+clunk
I started to think that maybe, with how strong the transmission is, that something else has loosened up over the time it has been in and it may not be the transmission itself. I really can't know for sure though until the car is out of the garage in a few months.
What you describe is exactly how my car is, with two different transmissions. I thought it had something to do with the shift kit, but apparently not.
https://ls1tech.com/forums/showthrea...ivetrain+clunk
I started to think that maybe, with how strong the transmission is, that something else has loosened up over the time it has been in and it may not be the transmission itself. I really can't know for sure though until the car is out of the garage in a few months.
What you describe is exactly how my car is, with two different transmissions. I thought it had something to do with the shift kit, but apparently not.
#3
TECH Fanatic
Thread Starter
iTrader: (32)
Join Date: Oct 2005
Location: Fairfax, Virginia
Posts: 1,687
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Haha, don't you recognize me? I posted in that thread. I started this thread to get some fresh information. Actually, I THOUGHT that thread was in the suspension section, so I started one in here because it seems transmission related.
I mean, even if it is a loose u-joint or something, why would it only be on the 2-3 shift? Makes no sense.
I mean, even if it is a loose u-joint or something, why would it only be on the 2-3 shift? Makes no sense.
#5
TECH Regular
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
mine did the same after pcmfor less tuned, and worse when i rebuilt my tranny and put in a shift kit.
well i just finished doing my own tune, and they have the line pressure higher and the shift pressure high so i pretty much drove and tune untill I like it and all the clunk have gone away . i have the CATS tunner
well i just finished doing my own tune, and they have the line pressure higher and the shift pressure high so i pretty much drove and tune untill I like it and all the clunk have gone away . i have the CATS tunner
#7
Pontiacerator
iTrader: (12)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Another member of the "clunk club" here ... posted in the other threads, too. I tried lengthening the low torque shift times and it didn't helped. After a while, I tightened them back up and it seemed a little better. I guess I could try raising low torque line pressure and see if that makes a difference.
Trending Topics
#9
TECH Fanatic
Thread Starter
iTrader: (32)
Join Date: Oct 2005
Location: Fairfax, Virginia
Posts: 1,687
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I got under the car and messed with the driveshaft. My u-joints are not loose at all, but there is some play. When I twist it, I'll get the clunk coming from the tailshaft of the transmission. Like something is loose inside. I don't hear it from the rear end side, especially cause the ring & pinion is new with no back lash. So is it normal to have some play in it?
#16
TECH Addict
iTrader: (3)
Join Date: Nov 2005
Location: Lincoln, NE
Posts: 2,869
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I don't know about that...mine did not do it when this transmission first went in...it took about 1000 miles to develop slowly. 3rd gear used to be a nice shift, but now I cringe every time I wait for it.
#18
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Another member of the clunk club here. Car was purchased used so take it with a grain of salt, but to the best of my knowledge tranny and tune are stock. Identical issue though. Worse when warmed up and only at light throttle. I've had the car for 2 years now and I think it's always done it to a degree but can't really remember. I have a feeling my trans is on a slow decline though. The other day on the highway I was going about 65 and went WOT. Tranny downshifted to 2nd I think it slipped a bit... UHOH $$$.
Maybe I'll just go with the idea that the tires spun a little![Rolleyes](https://ls1tech.com/forums/images/smilies/LS1Tech/rolleyes.gif)
If I do need a new tranny soon I'll let you know if it stops but it makes me feel better (maybe) that this is such a common problem.
Maybe I'll just go with the idea that the tires spun a little
![Rolleyes](https://ls1tech.com/forums/images/smilies/LS1Tech/rolleyes.gif)
If I do need a new tranny soon I'll let you know if it stops but it makes me feel better (maybe) that this is such a common problem.
#20
TECH Regular
iTrader: (1)
Join Date: Mar 2004
Location: Downey, California
Posts: 484
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
well i'm still messing around with mine w/ the shift pressures I still have alittle from 2-3 I took alittle more pressure out and see if that will work,
I have alimated all the clunk I also had alittle from 2-1 and removed alittle pressure from the down shift tables...
But when my car goes around 50-45 w/no gas it wants to buck alittle like the car is trying to push the motor ?
I don't know if it will work but i'm trying to take some steps out of the Throtle IAC follower vs mph at around those speeds and see if that will work.
the one reason I think I have the clunk is because I have the shift kit I never had this prob before and my tranny shifted great I mainly put it in because my 3-4 clutches were burning alittle and added the kit to prevent that.
I have alimated all the clunk I also had alittle from 2-1 and removed alittle pressure from the down shift tables...
But when my car goes around 50-45 w/no gas it wants to buck alittle like the car is trying to push the motor ?
I don't know if it will work but i'm trying to take some steps out of the Throtle IAC follower vs mph at around those speeds and see if that will work.
the one reason I think I have the clunk is because I have the shift kit I never had this prob before and my tranny shifted great I mainly put it in because my 3-4 clutches were burning alittle and added the kit to prevent that.