Gear Ratio

I`m getting ready to replace both axle assemblies in my `97 LeSabre. I noticed two ratios are offered for my auto, a 3.06 and a 2.84. I know checking the trans SPID code located on spare tire cover is the fastest and easiest way to determine which axle I have. Is one of these ratios standard and the other an option? Just curious.

Sorry for not answering your question, just wanted to add one thing I know about it.
One gets 3-4 MPG better then the other.

Chris.

Is one of these ratios standard and the other an option?
SPID code # F17 (2.84 Ratio) is standard and the 3:05 ratio SPID code F83 was optional with the F-41, or Y56 package.

Most parts stores never ask for the gear ratio when getting axles.I know the nearest Carquest and Auto Value parts in my area never do ask what the gear ratio is

It would help to know what year the car is..

If the Lesabre is 92-97

F17 2.84 or FW2 3.06

It would help to know what year the car is..

If the Lesabre is 92-97

F17 2.84 or FW2 3.06Please note my original post, the year is there.

My fault for not noticing that...

1997 was the last year for the 4T60-E in a Lesabre..

So you will either have the F17 or the FW2...

are both of your axles bad?

Which one is the good gas mileage ratio?

The F17 2.84 ratio is the one for good mileage...

32-34 on the hwy with a good state of tune can be expected...

Yep, 32 MPG is not uncommon at all for me to achieve on the interstate. Jrs, you asked if both my axles were bad, so far they are both silent and the rubber is good, but the car has 180K on the odometer and I just wanted to change them before they went out on me in the middle of nowhere. I drive a thousand miles round trip bi-monthly going to work and I travel through some very unsatifactory territory.

Generally the stock GM ones are the best..

I do recommend that you get the best ones you can..

I have almost 184,000 Miles on my 95 Bonneville and do not intend to replace the axles until the rubber goes.. I have no noise either and the rubber is also in good shape... I have replaced both sides on my 95 Van.. Both had the rubber split, one side did it twice.. Both were aftermarket when I got the van.. and didn't last too long.. I wish the factory parts were cheaper..