gear ratio decoder

[abbyzdad]

the following might be helpful for those who tow or are going to change the size of their tires. the code definitions for the gear ratio (shown on the door tag as "axle") are as follows:

18 -- 3.08
19 -- 3.55
26 -- 3.73
27 -- 3.31
H9 -- 3.55 limited slip
B6 -- 3.73 limited slip

4.6 l models -- 8.8" diff.
5.4 l models -- 9.75" diff.

i don't know for sure if these apply to '03 and '04 models but should all years prior. also the 8th diget of the vin will indicate which plant manufactured your engine.

6 -- 4.6l windsor
w -- 4.6l romeo

L -- 5.4 windsor

if any of these are incorect please post correct info.

hope this is of some intrest, brian

 

[Guest]

I believe that should be H6 for the 3.73 limited slip.

 

[daveplot]

For the 03 the gear ratios are:

· H6 — 3.73 ratio, limited slip
· 16 — 3.73 ratio, non-limited slip

The eighth VIN position is the engine displacement and number of cylinders.

L — 5.4L, SOHC, EFI, 2V, V-8, gas
R — 5.4L, DOHC, EFI, 4V, gas
W — 4.6L, SOHC, EFI, V-8, gas

(The above is from the 03/04 Ford service DVD)

 

[Bjamin]

Axle Ratio Decoder

I'm new to this forum - That's what I was looking for - Thanks.

Three other question, are thos codes for 03's only, because I've to a 2000, and it says H9 for the axle on the door tag? Also, will any of the modification chips (like the Hypertech or the XCal2) change the ratio? Are the chips worth the money?

Thanks again,
Ben

 

[abbyzdad]

Bjamin,
welcome to the board. the 2000 you have (same as mine) with an H9 axle is the 3.55 limited slip diff. Chips will not change the gear ratio but are for engine performance modifications. As to worth the money, i'm not familiar with the performance gains achieved from a chip--maybe someone will chime in to shed some light on that one. Again, welcome and enjoy
Brian

 

[danketchpel]

Does anybody know the ring gear diameter for the '03 and later IRS differentials?

Are the 4.6 & 5.4 the same? How about with the HD tow & L.S. options? How strong are they?

I haven't found much info on the IRS diffs.

 

[stang99x]

The chip will net you between 5-25 Horsepower based on what you buy. You can get a programmer as from what I understand new age computers don't accept chips. Check out the Xcalibrator2, predator, and microtuners

 

[Bjamin]

I actually meant the programmer. Have you used or has anyon else used the programmers mentioned above or Superchips or Hypertech?