Skip the auto shop - Our mechanics make house calls

Q: Truck will shift sometimes then it doesn't shift. If you wait a while it will shift again. We are trying to figure out what's going on

asked by on

Truck will shift sometimes then it doesn't shift. If you wait a while it will shift again. We are trying to figure out what's going on

My car has 128795 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. The first thing ...

Hi, thanks for writing in. The first thing I recommend is to make sure the ATF (automatic transmission fluid) is full.

Does the transmission shift up a gear or two and stay in that gear, or does it drive fine for a bit, then stop shifting until you turn the car off or sit still with the motor running? Or, do you continue to drive and eventually it begins shifting again. Are there any codes?

What I would do if I were diagnosing your truck would be to connect a scanner and study the data while driving to know what is going on. Without said data and not quite being clear about what is happening, it comes down to solenoids or sensors that the TCM (transmission control module) uses to calculated shift points based on load values determined by the PCM (powertrain control module).

I’m afraid all I can offer you at this point is suggesting you make sure the fluid is full and clean. If it isn’t clean, begin by replacing the filter in the pan and do a transmission fluid exchange, not just pan drop with a drain and fill. This doesn’t get all the ATF out of the transmission, and when there are problems, it pays to be as thorough as possible.

I recommend the following inspection if you should need further assistance: Car hard to shift

Hope this helps and best of luck!

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Had high rpm in 2nd, till no oil pressure 2001 Dodge Ram 1500

Yikes - hope you're recovering quickly - what a serious personal event! It is possible that your truck engine also sustained major damage during this scenario - damaged connecting rod or main bearings. It might be something as simple as...

Q: 2010 Mini Cooper S - P0974 Trouble Code: Shift Solenoid A Control Circuit High

Hello - there are known issues with the valve body wearing out faster than should be normal on this transmission. I would check with a reputable transmission shop in your area for a rebuilt valve body. these are available with...

Q: oil low 2000 miles

Hello. When vehicles have higher mileage, it will burn oil faster and will lose a half-quart to a full-quart every 1,500-2,000 miles after the oil has been changed. This is normal for vehicles with higher mileage and does not require...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.