Powerglide band adjustment tips

The powerglide transmission has a single band.  It is used to hold the clutch drum during low gear operation.  If the powerglide band is not adjusted properly the following things can occur:

• Band failure (burning of clutch material)
• Slipping in low gear or no low gear function at all
• Shift flare between low and high gears
• Car rolling backwards when the transbrake is applied

The powerglide band should be adjusted to the following specs:

• Tighten the band adjustment screw to 72 inch lbs
• Unscrew the band adjuster three and a half turns (3.5)
• Tighten the band adjustment screw's locking nut

The band should be readjusted on a semi regular basis throughout the racing season.  BTE recommends using a heavy duty band adjustment screw to prevent band failure.  Stock band adjusters can bend and warp under heavy duty conditions.

See also:

BTE Kevlar Powerglide Band
BTE Wide Powerglide Band

What are the limits of a factory, stock or OEM powerglide case in a racing application?

For more than 30 years, racers have relied on a variety of OEM parts to complete their cars due to budget or due to a lack of suitable aftermarket parts.  In the last 10 years, this has started to change dramatically with the availability of aftermarket cases, housings, gears, and just about every other high performance transmission (or engine) component.

Aftermarket powerglide cases bring a lot of advantages over stock cores:

• Greater strength
• Revised oil channels optimized for racing
• Improved wall thickness to meet SFI safety requirements
• Elimination of non essential areas and features for OEM usage

However, stock cases still have plenty of applications in budget and entry level racing.  With the addition of a SFI approved bellhousing and case shield, a stock case be ready for competition.

What are the practical limits for the stock cases?  What are some important tips to remember when using a stock case?

BTE recommends using a polyurethane transmission mount.  Solid, rigid mounts are often too stiff for a powerglide case when a heavy car launches hard.  This will often lead to a crack in the case.

Also, stock cases are more prone to failure if a driveshaft, rear end, or u joint is not properly configured or faulty.

Finally, it is important to monitor line pressure when using a stock powerglide case.  Pressures over 245 lbs can cause leaks or cause cracks to form in the thin die cast aluminum found in some of the various casting versions.

BTERacing.com just received a face lift!

Our home page www.bteracing.com just received a small face lift.  We've taken feedback from you all and made the site easier to navigate.  We've also added a featured product feed in the right section of the site.  Check here for special pricing that can't be found anywhere else.

Also, if you haven't already signed up for our powerglide quick reference guide, please see this link.  The easy to print and share .pdf includes the critical specs needed for a powerglide racing transmission assembly.

Why is your car moving backward when applying the transbrake in your powerglide?

As a follow up to our previous blog posting, the other common problem with transbrake operation in powerglide transmissions is the transmission moving in reverse when the transbrake is activated.  Again, this can cause the car to roll out of the staging lights causing an instant loss.


Once again, we will review the normal transbrake operation:

1. You activate the transbrake solenoid in low gear when staging.  The solenoid pushes the brake valve to a position in the valve body that redirects fluid.
2. Fluid rushes within the transmission to apply the reverse clutch piston and reverse clutches.  This locks the transmission in a 1:1 fight between low gear and reverse.
3. You increase engine RPM to prepare the car for launch.  The transbrake remains locked and keeps the car in place.
4. You release the transbrake solenoid switch which removes fluid pressure from the reverse piston and clutches.  The car now has forward movement in low gear and accelerates down the track.

If the car is moving backward any during the transbrake setting and staging process, it is likely due to one of the following problems:
 

• Staging at an RPM that does not supply sufficient fluid volume -  OEM or weak pumps need additional RPMs to move fluid quickly and adequately to apply the reverse clutches.  Increasing your RPM before setting the transbrake is the first solution to try.
• Low gear band not holding. 
• The low gear band can be completely worn down which would prevent it from holding low gear
• The band needs to be re-adjusted
• The servo piston has failed, is leaking, or has broken a sealing ring
• The band adjustment screw has broken or is bent

Check these areas if you are having transbrake trouble in your powerglide transmission.  These are simple fixes!  If you have any questions, contact our technical department @ 1-662-851-3213.

Why is your car moving forward or rolling when applying the transbrake in your powerglide?

A common problem for powerglide racing transmissions equipped with transbrake valve bodies is any kind of movement when the transbrake is activated and the car is staged.  This happening during a race can often result in an instant red light and loss.



Normal transbrake operation:

1. You activate the transbrake solenoid in low gear when staging.  The solenoid pushes the brake valve to a position in the valve body that redirects fluid.
2. Fluid rushes within the transmission to apply the reverse clutch piston and reverse clutches.  This locks the transmission in a 1:1 fight between low gear and reverse.
3. You increase engine RPM to prepare the car for launch.  The transbrake remains locked and keeps the car in place.
4. You release the transbrake solenoid switch which removes fluid pressure from the reverse piston and clutches.  The car now has forward movement in low gear and accelerates down the track.

If the car is moving forward any during the transbrake setting and staging process, it is likely due to one of the following problems:

• Staging at an RPM that does not supply sufficient fluid volume -  OEM or weak pumps need additional RPMs to move fluid quickly and adequately to apply the reverse clutches.  Increasing your RPM before setting the transbrake is the first solution to try.
• Reverse is not being engaged with enough pressure or not at all
• From the solenoid to the reverse clutches, something is not applying the full force of the reverse circuit to give the transmission a firm transbrake hold.  
• Examine your transbrake solenoid operation and engagement.  Is it getting enough power?  Is it too old and need replacing?  Is it engaging all of the way?
• The reverse piston may have have a damaged seal, be worn, or just stuck all together.
• Make sure the valve body and governor support are properly secured.  A leak internally can affect the reverse fluid circuit.

A new powerglide pump like our high volume powerglide pump is a great replacement for the OEM unit.

With a fully operational reverse circuit, your powerglide transmission should be holding steady and not rocking when it is time to race.

A very cool rat rod from Denmark

One of our customers and friends from Denmark has one of the coolest retro rat rods I've ever seen:

This cool ride built by Steffen Nielsen delivers the power to the ground via one of our BTE Top Sportsman powerglide transmissions and a BTE 9.5" bolt together torque converter.

Photos from the BTE World Footbrake Challenge VII at Bristol Thunder Valley

Our own Shaun West just returned from Bristol Thunder Valley Dragway where the BTE World Footbrake Challenge wrapped up this past weekend.  A great weekend of footbrake bracket racing was had by hundreds of racers, their families, and friends.  We want to thank the promoters for welcoming us back again for the seventh time. 

You can see more photos on our Facebook photo gallery.