Skip the auto shop - Our mechanics make house calls

Q: Truck slightly jumps at high speeds

asked by on

I purchased a used car and it has approx. 96,000 miles. In the beginning, it drove very well, but then after a few days every time I’d remove my foot from the accelerator and then apply gas again, the truck would jump slightly, especially at high speeds. If I would apply the gas slowly, it wouldn’t do it. It was like the transmission might be slipping. I returned to the dealership (Ford) and was told that everything checked out okay. I even drove with a mechanic and showed him the problem, but since the truck is still under powertrain warranty, they don’t want to do anything. They said I’d have to take it to the Honda dealer, which I did. I paid the diagnostic fee to have it checked out. I drove with one of their techs and he noticed the hump after applying gas. After checking it, they explained that it wasn’t the transmission, but instead a Backlash in the differential (or something like that) - and that it was normal for that to happen and wouldn’t be covered under warranty. They said there’s always a bit of play on gear or something like that. That just doesn’t sound right to me. In my thinking, they don’t want to work on it since it is close to the end of the warranty. In your professional experience, what is the problem and what do you think would fix it?

Hello. It is possible that the rear differential is experiencing backlash. Backlash is normal in the differential and every truck will experience this. However, the backlash shouldn’t be so great that it causes the truck to jump. This may be covered under warranty, but if the dealership says that this is normal, they will not replace it under warranty. Another option would be to have the rear differential rebuilt. This option may be more cost effective than having a new rear differential put on the truck.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Engine light on with P0171 code

The cause behind diagnostic trouble code P0171 is easiest to find by looking at the secondary firing patterns on the Bank one cylinders. That will confirm if the too lean condition, that has caused the code to set, affects all...

Q: Car check engine light is off. Car accelerates by itself in drive from 0 to 60 miles an hour. Replaced aci, no codes on computer, 1999 Ford Taurus

Hello - your Taurus has a Recall (#98V204000) against the cruise control, which can cause unintended acceleration. In a related later issue, new Taurus models had problems with twisted accelerator cables - again, from the cruise control, which may have...

Q: Speedometer not working properly

There should be two speed sensors. One which is located on the back of the dashboard and one located down on the transmission. I am not sure which one you replaced, but I would recommend also checking the other one...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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.