Finally got my car to the track yesterday. Single turbo sbf 900rwhp w/ a brand new PTC th400. Did my burnout in high gear and went to stage the car. Lit the second bulb and went on the transbrake (3700 rpm) and when I released it the I felt a bang and the car acted like it tryed to go in reverse and then it took off. I didn't notice a problem until I went to shift down to second on the return road and I had no second gear. I checked the linkage under the car and the sifter and everything is aligned properly. Talked to a few people at the track and one person said it could be in the valve body and not to pull the tranny and have the pan pulled and checked. Another person said its the second gear band most likely. He said if it was in the valve body it would affect all the other gears. I have first and third and it makes no boise at all. The fluid looks like new still and I don't see any debris in it. Any advice would be greatly appreciated. I watched the video and the car did go into reverse and then took off......WTF.
Don Lamana
These guys are right about never doing first gear burnout. Don't let the tires grab at the end of burnout either this will also roll the sprag. You don't want to overfill these trannys either I weld a tube on drain plugs(tap center plug) even with the pan top to make sure it's not overfilled. Modify the filter to pull oil from the rear too.
Well, just got the call from the tranny shop. Rolled the sprag, has some burnt up clutches, some eaten up bushings etc. Also asked what I did to reverse? I said "what do you mean". Said the reverse bands?......were smoked also. My builder works with PTC quite a bit and he called them about this. They said I "was" supposed to be in neutral w/ the transbrake button engaged to use reverse. I was just putting it in reverse and backing up. They said the TCI brake requires you to use neutral w/ the button applied to back up. They say it will engage in reverse but at only 50 lbs of line pressure and in neutral w/ ythe button it will have 200lbs. Thats a first for me, I never heard of such a thing. Every transbrake I have had was either, put it in reverse like normal or put it in reverse and hold the button while backing up. Never heard of using neutral and pushing the button to back up. All I have to say is that PTC stands behind their product regardless, they shipped my tranny shop all the parts he requested and I even had them send me a Freddie Brown brake to replace the TCI. With the reverse manual valve body, neutral and first are too close for me, it wouldn't take much to screw up if your linkage or shifter gets misaligned. Any thoughts?
PTC uses both TCI and Freddie Brown brakes. I just don't like having neutral w/ the button pressed being reverse and 1 click down and thats 1st on the brake. The freddie brown uses reverse as reverse. PTC also said the Freddie Brown brake is a little faster.
does this apply even if u have a foward valve body th400. the 2-3 burnouts instead of the 1-2
Sell it...:-D
Buy a spragless trans and never look back...
This is what a reputable, progressive, market leading company like www.extremeautomatics.com has to say on the matter;
"Turbo 400 Extreme is the strongest fastest Turbo 400 on the planet. The Extreme Spragless Technolgy has been 6.40 @221. The other guys make claims of being the fastest but that record was shattered. Here is why the Extreme is the strongest unit built.
The most common failure in a Turbo 400 is the 2nd gear sprag. This is a mechanical part has to stop the direct drum turning in the opposite direction of transmission rotation the instant the 2nd gear is engaged. Imagine a 9lb drum turning at engine RPM and has to be stopped instantly. What typically happens is the sprag will wear and break or flip over causing a loss of 2nd gear. This will happen from a stock 400 to Hi HP units. The industry for years has worked to improve the problem GM built into the Turbo 400. The industry solution was to use a larger sprag out of a front wheel drive GM transmission referred to as (Super Sprag). This sprag is larger and has more surface area and it does extend the HP limitation of the 2ng gear sprag. The problem is the Super Sprag is still a mechanical part, it still wears and fails only at a higher HP level. No one seems to know what HP level this new sprag is reliable. When you shock a mechanical part it will fail period. That's what happens every time you pull the shifter on your 400 into 2nd gear.
Extreme Automatics came up with the solution. If the sprag is a mechanical part. It wears and fails due to shock load. How do we permanently fix it. We remove the sprag from the transmission. No sprag = No sprag Failure. The Turbo 400 Extreme is a Spragless 400 transmission. That's right!!! There is no sprag to break. The clutches will handle all the shock you can throw at them. You shock the clutch pack it will slip grab and go down the track. You shock a mechanical part it will explode. The Heart of the Extreme 400 is the valve body built for Extreme Automatics by Griner Engineering. Steve Griner started from a block of aluminum billet and a clean sheet of paper. The other guys are still modifying the 40 year old GM cast iron valve body. With the new Valve body the sky was the limit. We removed the 2nd gear sprag, Improved direct clutch life and designed the fastest shift time in the industry. All this was topped off with a Pro Tree .000 release time Griner trans brake the fastest in the industry. The spragless technology has been tested for years in 10,000lb Fuel Blown monster trucks where no sprag has ever survived. These trucks must be shifted up and down in and out of 2nd gear at full throttle. That's some serious punishment. Imagine a 10,000lb truck. On the Dragstrip the spragless has been 6.21 at over 230 in the quarter when the other big names 400s failed. If you are looking for the strongest 400 on the planet with the latest innovation The Extreme Turbo 400 is for you."
Then go and shift it like you stole it!!!
No more crap about what sequence you have to shift the "F"ing thing ever again...:-D
Buy a spragless trans and never look back...
This is what a reputable, progressive, market leading company like www.extremeautomatics.com has to say on the matter;
"Turbo 400 Extreme is the strongest fastest Turbo 400 on the planet. The Extreme Spragless Technolgy has been 6.40 @221. The other guys make claims of being the fastest but that record was shattered. Here is why the Extreme is the strongest unit built.
The most common failure in a Turbo 400 is the 2nd gear sprag. This is a mechanical part has to stop the direct drum turning in the opposite direction of transmission rotation the instant the 2nd gear is engaged. Imagine a 9lb drum turning at engine RPM and has to be stopped instantly. What typically happens is the sprag will wear and break or flip over causing a loss of 2nd gear. This will happen from a stock 400 to Hi HP units. The industry for years has worked to improve the problem GM built into the Turbo 400. The industry solution was to use a larger sprag out of a front wheel drive GM transmission referred to as (Super Sprag). This sprag is larger and has more surface area and it does extend the HP limitation of the 2ng gear sprag. The problem is the Super Sprag is still a mechanical part, it still wears and fails only at a higher HP level. No one seems to know what HP level this new sprag is reliable. When you shock a mechanical part it will fail period. That's what happens every time you pull the shifter on your 400 into 2nd gear.
Extreme Automatics came up with the solution. If the sprag is a mechanical part. It wears and fails due to shock load. How do we permanently fix it. We remove the sprag from the transmission. No sprag = No sprag Failure. The Turbo 400 Extreme is a Spragless 400 transmission. That's right!!! There is no sprag to break. The clutches will handle all the shock you can throw at them. You shock the clutch pack it will slip grab and go down the track. You shock a mechanical part it will explode. The Heart of the Extreme 400 is the valve body built for Extreme Automatics by Griner Engineering. Steve Griner started from a block of aluminum billet and a clean sheet of paper. The other guys are still modifying the 40 year old GM cast iron valve body. With the new Valve body the sky was the limit. We removed the 2nd gear sprag, Improved direct clutch life and designed the fastest shift time in the industry. All this was topped off with a Pro Tree .000 release time Griner trans brake the fastest in the industry. The spragless technology has been tested for years in 10,000lb Fuel Blown monster trucks where no sprag has ever survived. These trucks must be shifted up and down in and out of 2nd gear at full throttle. That's some serious punishment. Imagine a 10,000lb truck. On the Dragstrip the spragless has been 6.21 at over 230 in the quarter when the other big names 400s failed. If you are looking for the strongest 400 on the planet with the latest innovation The Extreme Turbo 400 is for you."
Then go and shift it like you stole it!!!
No more crap about what sequence you have to shift the "F"ing thing ever again...:-D
Ok.. What's the downside of making the TH400 spragless..
Does it use more power to turn ??
Do clutches wear out faster ??
Not trying to knock them, cause if I can find a way I will get me one.. Just want to know all the "in's and out's" ..
Does it use more power to turn ??
Do clutches wear out faster ??
Not trying to knock them, cause if I can find a way I will get me one.. Just want to know all the "in's and out's" ..
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