So what is happening when the TC is not in lockup, just pumping fluid to the transmission clutches?
CK5
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LSX454 swapped 95 BASS burb.
- Thread starter shady
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Little lower, little cooler, bigger sounds.
Yes the torque converter is supposed to be converting rpm to torque at that point, it works like a hydraulic gear multiplier, the stator redirects the fluid back to the turbine again and multiplies the torque with fluid coupling between the turbine and impeller. Only during TCC lockup is the torque converter supposed to be 1:1 ratio. The whole time the trans is shifting wet clutches, which are applied with hydraulic pistons, to change the actual planetary gear ratios.
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I just tried to get a log of it. And yes it did it in first gear once and I believe it was caught in a log.
It never did it as bad as those vids this time though.
It also started up, but wouldn't idle at all. Took me half a dozen starts to get it out of the garage.
That's completely un normal.
Tried with that 'idle spark' on and off. Same result.
That's the only change I've made in a long time, so no idea what that was about.
It never did it as bad as those vids this time though.
It also started up, but wouldn't idle at all. Took me half a dozen starts to get it out of the garage.
That's completely un normal.
Tried with that 'idle spark' on and off. Same result.
That's the only change I've made in a long time, so no idea what that was about.
Just google how a torque converter works. The pump is pumping fluid to all the clutches. The torque converter is transferring the engine torque to the transmission via fluid.
Ok.
So when mine was shuddering in 2nd and 3rd and was cured from the fluid Greg advised to use and it went away, could it be making the fluid passages clear so the pressure is more consistent?
I am trying to understand what my issue was and if his is similar.
Mine was a 4l60e which I am sure is the same as 4l80E
That tire mark tells me what ever made that was bucking like a bronco. LolNo I wasn't logging, didn't expect it to do it.
It only does it trying to accelerate. You can here the throttle and what I was doing with it. It was mild acceleration, then I did it a little harder. Then when I gun it a little, it didn't do it.
I keep wondering if I have rear end issues. If something in the gov loc could be messing with me, or
Mainly because of this tir mark.
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Your gov lock may be to blame here. What rear end do you have 14ff? Do you have any spare carriers to swap in, even an open one just to test and see?
Does this happen on light acceleration, heavy acceleration or both?
If it's stable under heavy throttle, could it be something w/ programming? Not enough pressure at low throttle?
If it's stable under heavy throttle, could it be something w/ programming? Not enough pressure at low throttle?
Never bucked, bounced, or nothing
felt like a smooth burnout. Then went back and looked and seen that.There is a LOT of marks around that spot, but I'm fairly certain that mark is mine.
I have all my pressures at 5% duty cycle across the board right now.
So nearly maxed.
Already not happy with the GM genuine tensioner.
ALL of the aftermarket options for the serpentine have a 3rd bolt withal a braced piece to prevent flex in the direction of the tension.
The GM just relies on 2 tall bolts.
It's the worst design of them in my book.
If I had noticed that, I would have still bought something else again.
ALL of the aftermarket options for the serpentine have a 3rd bolt withal a braced piece to prevent flex in the direction of the tension.
The GM just relies on 2 tall bolts.
It's the worst design of them in my book.
If I had noticed that, I would have still bought something else again.
New tensioner and belt DO seem to operate smoother
I could feel some scratchy BS inside when I operated the old one to get the belt off.
So I had to have damaged it inside.
If I can get an RPM belt I'm still getting one. It's designed for high torque and SC applications.
Gatorback doesn't exist anymore.
Now it's Continental Elite. But nothing I can give and says they're designed not to stretch as much as a normal belt like the Gates RPM.
Only found one place that seems to have the RPM in what size I need and it's $194
I don't want it THAT bad yet lol.
View attachment VID_20250709_160616548.mp4
I could feel some scratchy BS inside when I operated the old one to get the belt off.
So I had to have damaged it inside.
If I can get an RPM belt I'm still getting one. It's designed for high torque and SC applications.
Gatorback doesn't exist anymore.
Now it's Continental Elite. But nothing I can give and says they're designed not to stretch as much as a normal belt like the Gates RPM.
Only found one place that seems to have the RPM in what size I need and it's $194
I don't want it THAT bad yet lol.
View attachment VID_20250709_160616548.mp4
It's probably to consolidate part numbers
Also is it just me or does your second alternator looks a little crooked?
It is but it looks worse than it really is.
It's a homade bracket, and I can't seem to get it just right.
It has a 1/4" spacer that needs shaved a few thousandths. But I haven't figured out a good way to do it evenly.
Then I'd need the same amount in shim behind it too.
It's a homade bracket, and I can't seem to get it just right.
It has a 1/4" spacer that needs shaved a few thousandths. But I haven't figured out a good way to do it evenly.
Then I'd need the same amount in shim behind it too.
From Ricks recent data log...
The input speed is supposed to be locked to the speed at a ratio depending on the gear you are in, because behind it is just gears and clutches. In front of it is the turbine, impeller, and stator that can slip. Also the OD gear but that only counts in OD, and the TCC but that only counts when locked, so ignore both for now.
Now look what happens, when you give it a little throttle, RPM starts to climb, input shaft starts to climb very fast, then the output speed starts to stutter first, then it transfers to the input speed. But first the trans slips because input speed climbs very fast. Then when you let off a little and it shifts to 2nd gear, the output stutters again, not the input, it drops to 2nd gear. Then it does it again when you let off completely. Your speed is not smooth.
This means the stutter is likely starting somewhere in either the trans, tire, shocks, suspension, axle, driveshaft, etc. Somewhere behind the input shaft. Its possible its in the trans because of the stutter during the initial slip.
For illustration of what a good log shows, here is a a few year old datalog with the same data showing from my car on an NA pass.
You can see where I'm on the transbrake/2 step, then you can see the launch. You can see during the launch my body shifting back actually let off the throttle about 10%, I needed to put my seat forward 1 notch and/or hold tighter.
You can see my converter is too tight, the RPM climbs, drops a tad, then climbs again. Its not because of the throttle because it does that at 100% throttle too, and my car with the 2200 CFM throttle body will actually run the same time at 80% throttle, because the throttle blades are still very close to wide open, that is not normal, just a huge throttle body.
Then you can see how 1st gear RPM climbs real fast, then 2nd gear not quite as fast, then 3rd gear is 1:1 with speed. Speed also climbs slower because of both gearing and wind resistance, not accelerating as fast at 140 MPH vs 40 MPH.
You can see a tiny but of tire spin on the 2nd gear shift.
Then you can see at no throttle during the decel the speed is higher than engine RPM until the converter lets it idle again.
The input speed is supposed to be locked to the speed at a ratio depending on the gear you are in, because behind it is just gears and clutches. In front of it is the turbine, impeller, and stator that can slip. Also the OD gear but that only counts in OD, and the TCC but that only counts when locked, so ignore both for now.
Now look what happens, when you give it a little throttle, RPM starts to climb, input shaft starts to climb very fast, then the output speed starts to stutter first, then it transfers to the input speed. But first the trans slips because input speed climbs very fast. Then when you let off a little and it shifts to 2nd gear, the output stutters again, not the input, it drops to 2nd gear. Then it does it again when you let off completely. Your speed is not smooth.
This means the stutter is likely starting somewhere in either the trans, tire, shocks, suspension, axle, driveshaft, etc. Somewhere behind the input shaft. Its possible its in the trans because of the stutter during the initial slip.
For illustration of what a good log shows, here is a a few year old datalog with the same data showing from my car on an NA pass.
You can see where I'm on the transbrake/2 step, then you can see the launch. You can see during the launch my body shifting back actually let off the throttle about 10%, I needed to put my seat forward 1 notch and/or hold tighter.
You can see my converter is too tight, the RPM climbs, drops a tad, then climbs again. Its not because of the throttle because it does that at 100% throttle too, and my car with the 2200 CFM throttle body will actually run the same time at 80% throttle, because the throttle blades are still very close to wide open, that is not normal, just a huge throttle body.
Then you can see how 1st gear RPM climbs real fast, then 2nd gear not quite as fast, then 3rd gear is 1:1 with speed. Speed also climbs slower because of both gearing and wind resistance, not accelerating as fast at 140 MPH vs 40 MPH.
You can see a tiny but of tire spin on the 2nd gear shift.
Then you can see at no throttle during the decel the speed is higher than engine RPM until the converter lets it idle again.
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I put an orange line with what it should look like on the input shaft...
If I change the scale so the input and output overlap, you can see it easier....this is not during a gear change...just a throttle change...t could be a combination of both(trans slip and wheel hop). Its hard to tell not being there in person.
If I change the scale so the input and output overlap, you can see it easier....this is not during a gear change...just a throttle change...t could be a combination of both(trans slip and wheel hop). Its hard to tell not being there in person.
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I wish there was a good way to see wheel slip on camera. But I'm always moving when this happens, so there's really no easy way to get it.
I thought about white marks on my tire, then pointing the GoPro straight down off the fender. But I still don't know if it'd be visible.
I thought about white marks on my tire, then pointing the GoPro straight down off the fender. But I still don't know if it'd be visible.
So, the caltracs, although needed for wrap, don't seem to have changed the stutter deal.
Maybe even amplified it.
This is accelerating moderately right after the 1-2 shift.
That is NOT the road.
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How good are your motor mounts? Shock bushings?
