Start the engine and place the transmission in drive while holding the brake pedal under firm pressure so the vehicle does not move. Then
push the accelerator to the floor while holding the brakes on
. Note the maximum rpm the engine reaches. This is the stall speed.
How do you conduct a stall test?
While holding the brake pedal,
press and hold the throttle pedal to the floor for 2 or 3 seconds
. Always check with the manufacturer’s recommendations because the test places stress on the transmission. Never exceed 5 seconds. Compare the reading (stall speed) on the tachometer to the manufacturer’s specifications.
What is checked during a stall test?
Stall test consist of
determining maximum engine speed obtained at full throttle in “D’ and “R” positions
. This test checks torque converter stator overrunning clutch operation, and holding ability of transaxle clutches and low-reverse brake. During this test, make sure that no one stand in front of or behind vehicle.
How do you know if you have a stall converter?
Hold the brakes as hard as possible and slowly load the throttle against the brakes
and see at what RPM either you can’t hold the car still or it breaks the tires loose.
How does a stall work?
Stall is
when the transmission is in gear
, but the brakes prevent the car from moving. At stall, the torque converter can produce maximum torque multiplication, called stall ratio, if sufficient input power is applied.
Will I fail my test if I stall?
There are many things falsely believed to lead to instant driving test failure, stalling being a common one.
You do not fail automatically for stalling
, unless you do so repeatedly or when pulling out on to a major junction where it is deemed unsafe. The same goes for rumours that you will fail for crossing your hands.
What would a low stall speed during a stall test indicate?
The RPM the engine maxes out at is the stall speed. Interpreting the stall-speed test result If the RPM reading is lower than the specifications for your particular torque converter and engine, it means
the torque converter is failing and needs to be repaired or replaced
.
What are the signs of a failing torque converter?
- Loss of Acceleration. …
- Slipping Between Gears. …
- Vehicle Won’t Shift at All. …
- Transmission is Overheating. …
- Transmission Fluid Leak. …
- Bad Transmission Fluid.
What happens if torque converter stall is too low?
Converter stall speed must be high enough to put the engine into the torque range where it can most efficiently launch the car. If converter stall speed is too low,
the car will be lazy leaving the line
; if too high, there’ll be excessive high-gear slippage—either case adds time to your e.t.
How do I choose a stall?
When choosing the stall speed that is right for your application, a rule of thumb is that the advertised stall speed
will need to be at least 500 rpm higher than the beginning of the camshaft’s powerband
. All aftermarket camshafts are delivered with a recommended RPM operating range.
What is the difference between a low stall and a high stall torque converter?
For many street trucks that are used for towing, daily driving, and performance, owners choose a
lower-than
-stock stall converter. While high-stall converters are the ticket for racing, they generate lots of heat due to high slip percentages and can create a huge rpm drop when lockup is engaged.
What is a good street stall converter?
Generally,
a 2,000 or 2,400-stall converter
is a good choice for advertised cam durations up to 248 degrees. For advertised cam durations up to 268 degrees, a 2,400 or 3,000-stall converter is the way to go.
How much is a stall converter?
Torque Converter Replacement Costs
If you plan on fixing it yourself, then you’ll spend
around $150 to $500
. On the contrary, taking the vehicle to the transmission shop may require $600 to $1000 to cover the repair costs.
What stall converter should I use?
For mild performance cars with something like a 350 HP engine, a
2,200 – 2,400 stall
is about right. The basic rule of thumb is; if your engine “comes alive” at say, 3,500 RPM, then you want a stall converter with about 3,500 of stall to it.
What is indicated when the stall speed is too high?
If the stall speed is too high, it indicates
slippage in either the direct/reverse clutch or in the 1st/reverse clutch
. All of these faults require that the transaxle be removed and disassembled for repair.
How does gear ratio affect stall speed?
Transmission gearing will also be a factor in your stall speed. The rule is,
the numerically lower the gear ratio is in the transmission, the higher the stall speed that would be required
.
