Diff Ratio 4.90 or 4.88 it is the same ???

[caxtrol]

Hey Guys

I have a short Mitsu 98 with 3.5 V6 and 4.27 Diff Ratio.

I got a 4.88 front diff from a Short Mitsu 94 3.0 V6, but I found a Rear Diff from 2.8 TDI in 4.90....

My question is for the rear diff, it is the same 4.88 with 4.90 ???, because I saw in the Forum that:

3.5V6 & 2.8TDI :-
front axle = 28 spline, 29mm diameter, diff = 8" diameter (high pinion)
rear axle = 31 spline, 33.5mm diameter, diff = 9.5" diameter

and

Gen 2

3.0 V6 = 4.625, 4.875
2.8D = 4.875
2.8TDI = 4.90

Please, If somebody could give me a hand with it .....

Thanks

Caxtrol

[NJV6]

No they are not the same.

The 4.900 is the bigger one.

Dare I say it, if you had free wheeling hubs and never used super select on the highway then you'd not notice the 0.25 ratio difference.

[caxtrol]

Ok

I do not have free wheeling hubs and I used super select, because my Mitsu is year 98, and for this reason I am understanding that I can not use 4.875 in the fron and 4.90 in the rear, I am thinking in the correct way ????

Thanks

Caxtrol

[-Scott-]

The difference in ratios is .025, or a little over 0.5%. You'll get a bigger difference due to tyre wear & tyre rotation.

For example, if you have 33" tyres, 0.5% would be less than 0.2", or less than 5mm in diameter - which is 2.5mm in tread depth.

Just do it.

[caxtrol]

Ok, if I have 33` the diference is nothing, and I will not have a problem with 4.875 in the front and 4.90 in the rear ????

It is correct ???

Thanks again

Caxtrol

[Hekta]

Scott was just using the tyre size as an example.

Just do it. The difference in ratios is small enough that it won't cause a problem.

[-Scott-]

Scott was just using the tyre size as an example.

Just do it. The difference in ratios is small enough that it won't cause a problem.

Yes. I was trying to show that it's less of a difference than new tyres on one axle, and part worn tyres on the other.