Converter shudder HELPPP.....
Thread Starter
Racer
Joined: May 2004
Posts: 270
Likes: 0
From: NORFOLK VA.
Converter shudder HELPPP.....
OK I took the motor and trans out of my 85 IROC ( 406 &700r4)installed it in my 85 Vette now when the trans shifts into 4th gear and locks up it shudders its azz off the trans has a midwest 3200 converter and it didnot do this in the IROC I changed the lockup solonoid no difference, now the IROC had 373 gears and the Vette has 307 gears that shouldnot make any difference, any ideas could it it be a programming issue. 
Drifting
Joined: Mar 2002
Posts: 1,251
Likes: 2
From: Thomson Georgia
I would have to say the TCC was marginal and the 373s help to cover it up - higher run rpms, higher highway rpms.
The 307s put a higher load on the TCC - lower throttl position, less line pressure at the same speed = slippage.
Sounds like rebuild time or replacement or unhook the lockup solenoid or light foot it.
The 307s put a higher load on the TCC - lower throttl position, less line pressure at the same speed = slippage.
Sounds like rebuild time or replacement or unhook the lockup solenoid or light foot it.
Drifting
Joined: Mar 2002
Posts: 1,251
Likes: 2
From: Thomson Georgia
You can go into the bin file and adjust max, min speed, gear ratio. The throttle pressure setting has a lot to do with it. If you set one to shift soft and early - good chance of shudder. Higher and stiffer - less chance of shudder to a point.
There is a big relationship to where the attachment point is on the throttle body to throttle shaft which determines how quickly you apply pressure via the cable, vs speed which has a lot to do with shift point, firmness, OD, etc. Most of them are not mounted in the right spot on most of the throttle bodies and again, it makes a BIG difference in shift firmness, shift timing, life of the tranny.
There is a big relationship to where the attachment point is on the throttle body to throttle shaft which determines how quickly you apply pressure via the cable, vs speed which has a lot to do with shift point, firmness, OD, etc. Most of them are not mounted in the right spot on most of the throttle bodies and again, it makes a BIG difference in shift firmness, shift timing, life of the tranny.
Pro
Joined: Jan 2004
Posts: 503
Likes: 0
From: Forney Texas
I had the same syptoms you are experiencing. I found my throttle valve was out of adjustment. After adjusting it several times in small increments, my problem went away. I have a 90 so what I am telling you may or may not apply. I can tell you that this "fix" was not mentioned in either the factory service manual or the factory transmission manual. Good luck.
90Indy
90Indy
Thread Starter
Racer
Joined: May 2004
Posts: 270
Likes: 0
From: NORFOLK VA.
Originally Posted by johnnyevans
I would have to say the TCC was marginal and the 373s help to cover it up - higher run rpms, higher highway rpms.
The 307s put a higher load on the TCC - lower throttl position, less line pressure at the same speed = slippage.
Sounds like rebuild time or replacement or unhook the lockup solenoid or light foot it.
The 307s put a higher load on the TCC - lower throttl position, less line pressure at the same speed = slippage.
Sounds like rebuild time or replacement or unhook the lockup solenoid or light foot it.
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Drifting
Joined: Mar 2002
Posts: 1,251
Likes: 2
From: Thomson Georgia
I know the feeling. I've been running a 3k stall Raptor converter with a kevlar clutch. It hits firmly. Full throttle lockups are not a problem, very hard 1-2 on the 89. I am not endorsing Raptor, just giving info.
Just go ahead and pull it down and put another converter in it, don't forget the front pump seal when you do.
Johnny
Don't run it until the clutch starts shredding, then it's tranny rebuild time
Just go ahead and pull it down and put another converter in it, don't forget the front pump seal when you do.
Johnny
Don't run it until the clutch starts shredding, then it's tranny rebuild time
Thread Starter
Racer
Joined: May 2004
Posts: 270
Likes: 0
From: NORFOLK VA.
Originally Posted by johnnyevans
I know the feeling. I've been running a 3k stall Raptor converter with a kevlar clutch. It hits firmly. Full throttle lockups are not a problem, very hard 1-2 on the 89. I am not endorsing Raptor, just giving info.
Just go ahead and pull it down and put another converter in it, don't forget the front pump seal when you do.
Johnny
Don't run it until the clutch starts shredding, then it's tranny rebuild time
Just go ahead and pull it down and put another converter in it, don't forget the front pump seal when you do.
Johnny
Don't run it until the clutch starts shredding, then it's tranny rebuild time
Thread Starter
Racer
Joined: May 2004
Posts: 270
Likes: 0
From: NORFOLK VA.
Originally Posted by johnnyevans
It was less than $300 a couple of years ago. If you need it, I'll see if I can round up a name and # for you.
THANKS
