Troubleshooting & Symptoms

8L90 Transmission Problems: What Fails First Behind Real Power

8L90 Transmission Problems: What Fails First Behind Real Power

Gearstar Performance 10 minute read

Five things account for most 8L90 complaints: torque converter shudder, harsh or delayed shifts, slip under load, heat, and valve body or solenoid wear....

Automatic Transmission Failure: Catch It Before the Case Fills With Metal

Automatic Transmission Failure: Catch It Before the Case Fills With Metal

Gearstar Performance 12 minute read

Automatic transmission failure is a heat problem, a pressure problem, or a control problem that got driven on. The unit that comes in on a hook with a cracked...

Automatic Transmission Problems: 10 Signs a Built Car Gives You First

Automatic Transmission Problems: 10 Signs a Built Car Gives You First

Gearstar Performance 9 minute read

A transmission almost never quits without warning. It slips, it flares, it hangs a beat going into gear, and the fluid goes dark weeks before anything...

Gearstar-built 4L80E Level 5 heavy-duty GM automatic transmission

GM Transmission Problems: Common Issues in Cars and HD Trucks

Gearstar Performance 8 minute read

You feel a slip on the 2-3 shift, a flare under load, or a shudder at highway speed, and you search "GM transmission problems." The first thing to know...

No Recess!

Ryan Steele 6 minute read

I can remember back when Total Cost Involved was about to drop the '58 Chevy 235 engine and Gear Star Turbo 350 trans in my '39 just as they finished...

What Happens When a Transmission Range Sensor Goes Bad?

Ryan Steele 9 minute read

The transmission range sensor tells the transmission control module which gear the shifter is in. When it goes bad, the TCM works off bad information and...

What Happens If Your 700R4 TV Cable is Out of Adjustment?

What Happens If Your 700R4 TV Cable is Out of Adjustment?

Gearstar Performance 4 minute read

SUMMARY:Throttle valve cables manage the hydraulic pressure and shift timing of your transmission. When the TV cable isn’t in sync with your throttle, it can affect...

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