Drivetrain clunk...
TECH Enthusiast
Joined: Feb 2005
Posts: 563
Likes: 0
Originally Posted by BlackHawk T/A
Alright I've hung out in here for quite a while but have never been one of the guys posting their problems. Well until now...there is a first time for everything.
I get a real bad clunk when shifting into 3rd gear, and 3rd gear only. 2nd feels good, and 4th feels good. But 3rd clunks hard and it is throttle dependent. The lighter the throttle the harsher it is. If I am on it more, it isn't as noticeable. At WOT, it is not there at all.
It sounds like it is coming from right under me, and sometimes toward the rear, and it feels bad. It's almost like torque management with a little hesistation right during the shift, but my TM is long gone. Again the clunk/hesitation hits right at the 3rd gear shift. It also seems to be worse when driving in 3 as opposed to D.
It sounds like a "pop" and it can't be good. I haven't gone looking for the problem yet but if anyone can throw some ideas my way it would be appreciated...I really hope it isn't the transmission, being the most expensive thing I have done to the car. I also don't remember it doing this when I put the transmission in the car. It has definetely developed over the past few months.
I get a real bad clunk when shifting into 3rd gear, and 3rd gear only. 2nd feels good, and 4th feels good. But 3rd clunks hard and it is throttle dependent. The lighter the throttle the harsher it is. If I am on it more, it isn't as noticeable. At WOT, it is not there at all.
It sounds like it is coming from right under me, and sometimes toward the rear, and it feels bad. It's almost like torque management with a little hesistation right during the shift, but my TM is long gone. Again the clunk/hesitation hits right at the 3rd gear shift. It also seems to be worse when driving in 3 as opposed to D.
It sounds like a "pop" and it can't be good. I haven't gone looking for the problem yet but if anyone can throw some ideas my way it would be appreciated...I really hope it isn't the transmission, being the most expensive thing I have done to the car. I also don't remember it doing this when I put the transmission in the car. It has definetely developed over the past few months.
I had a small clunk under light load into 3rd. It sounded like play in the ring/pinion, but turned out to be a tranny mount. The mount looked fine. I replaced it anyway and problem fixed.
JA
Sorry to bring this up months later. Did you ever resolve this issue? Cause I'm getting the EXACT symptoms as you. Makes clunk into third with little or no throttle. And driving at high rpms (about 3K) then giving it some gas will do it also. Downsifts are bad into 1st.
However, instead of what you installed.. I put in a tunnel brace mounted torque arm.
This is NOT normal.
However, instead of what you installed.. I put in a tunnel brace mounted torque arm.
This is NOT normal.
Joined: Nov 2003
Posts: 6,216
Likes: 236
From: Wichita KS / Rancho San Diego
Originally Posted by JGA
I had a small clunk under light load into 3rd. It sounded like play in the ring/pinion, but turned out to be a tranny mount. The mount looked fine. I replaced it anyway and problem fixed. JA
I'm getting the EXACT symptoms as you. Makes clunk into third with little or no throttle. Downsifts are bad into 1st.
Im not totally sure if this is what it is however I have felt what seems like quick drag bump at light throttle after a shift kit install when a large servo is used in both the 4l60e and the 700r4.
In the ones I have dealt with it was actually band/3-4 clutch overlap this happens if the band dosent release before the 3-4 clutch applies for the third gear shift.This was alleviated by enlarging the 3rd accumulator feed hole in the spacer plate,Many kits use a aluminum plug to restrict this feed. Which is fine with most of the stock servos, However due to the decreased release area of the sonax and superior servos and in some cases if the feed is very small the corvette servo you can get this effect
Further explained the 2nd oil applies the servo this side of the servo has less area and the band is applied , Then when the 3-4 clutch comes on during the 3rd shift the same oil thats used to apply it comes in behind the servo and releases it since the area on the back side of the servo is larger,If the oil to there is not quick enough you will have a drag bump feeling particularly at lower throttles.
In the ones I have dealt with it was actually band/3-4 clutch overlap this happens if the band dosent release before the 3-4 clutch applies for the third gear shift.This was alleviated by enlarging the 3rd accumulator feed hole in the spacer plate,Many kits use a aluminum plug to restrict this feed. Which is fine with most of the stock servos, However due to the decreased release area of the sonax and superior servos and in some cases if the feed is very small the corvette servo you can get this effect
Further explained the 2nd oil applies the servo this side of the servo has less area and the band is applied , Then when the 3-4 clutch comes on during the 3rd shift the same oil thats used to apply it comes in behind the servo and releases it since the area on the back side of the servo is larger,If the oil to there is not quick enough you will have a drag bump feeling particularly at lower throttles.
__________________
I have the same thing in my 4L60. Its on the 2-3 shift. Clunks pretty good at light throttle. Also can notice a clunk back in when decellerating and hit the gas. As far as I know, I haven't put a shift kit in, but, who knows, the previous owner could have.
Yeh, it mostly happends at shifts. Really annoying cause I go over speed humps and it will clunk when downshifting 1st, then clunk accelerating again when it shifts to 3rd. BTW: I JUST put in a new rubber tranny mount to see if it would fix it, but it didn't. And what is interesting, I only installed a torque arm, and you all did shift kits.. but we are getting similar problems.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by BlackHawk T/A
This is going to sound extremely simplistic but...is the torque arm torqued completely tight? How about the bushing?
I have noticed it is temperature related. Its very cold right now.. and untill the car is half way hot, I do not, or barely feel the clunk. It happens once the car is pretty warm.
I am going to re-check the pinion angle tomorrow because I believe it changed with the new tranny mount (tranny not sagging anymore).
I have the same problem. Ive just learned to live with it. Very light throttle into 3rd and it clunks. 1-2 feels great. Maybe its just normal or if not normal than not damaging to the trans. Im going to try and convince myself that normal and forget about it.
Ok, I'll try to get over it then. But it makes no sense that my torque arm instigated the problem. I'll do a trans flush to see if its an oil problem. Other than that, I'll stop posting about it.
Joined: Nov 2003
Posts: 6,216
Likes: 236
From: Wichita KS / Rancho San Diego
Originally Posted by SPRAYED 01
I have the same problem. Ive just learned to live with it. Very light throttle into 3rd and it clunks. 1-2 feels great. Maybe its just normal or if not normal than not damaging to the trans. Im going to try and convince myself that normal and forget about it.
TECH Resident
Joined: May 2006
Posts: 969
Likes: 119
If you can get the Trans-Go 700R4 (SK700-Jr-B) instructions, go to page two, step two, and grind the 4 oil exit notches on the steel cover. This will help eliminate this clunk. I have been including these instructions in the 4L60E Trans-Go Performance Shift kit just recently to help eliminate this problem. I can fax you the instructions on this if you desire, just email me a phone number.
