Skip the auto shop - Our mechanics make house calls

Q: Front diff ratios

asked by on

I have a 2005 3.0 sport diesel, the front diff needs replacing, the ratio is 3.91. I've been told a 3.73 would fit is this true? If so would I need to change anything else or is it a straight fit
My car has an automatic transmission.

Hello. If you are going to change the ratio, it needs to be done in the rear also. You cannot have different gear ratios in the front and the rear as that would cause the transfer case to fail. These must always match to function properly.

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: How Long Does Clutch Fluid Last?

Clutch fluid in most vehicles is the same as what is used in most brake systems, brake fluid. The fluid over time will get contaminated with moisture, dirt, debris, and internal clutch master and slave cylinders wear materials. All of...

Q: Car cutting out when slowing down

This may be related to a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at...

Q: engine is shaking - 2006 BMW 325i

Hello. This may be a sign of a failing idle air control valve. The idle air control valve is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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...