4.0L Gear
#1
4.0L Gear
One person said our 4.0L has a 3.29 gear and someone else said we had a 3.31 gear... which one is it??? And anyone who has a 3.73, does it work really well? Does it make a big difference rather? Thanks again as always for the help from you guys!
#8
RE: 4.0L Gear
ORIGINAL: fazm
3.31 in both auto and manual.
and yes 3.73s are just awesome, i love mine (installed when i did the truetrac)
3.31 in both auto and manual.
and yes 3.73s are just awesome, i love mine (installed when i did the truetrac)
Bottom line... what's the upside for the 3.73's, at all speeds, and where are the downsides?
#10
RE: 4.0L Gear
Go with the 3.73's and upgrade your diff to a t-lok (traction lock) or other posi-trak type diff. Be sure and get the bearings, seals, and shims kit, those parts are not allways in stock for the 7.5 inch diff that's in the V6 mustangs.
I have noticed dramatic improvement in drivability both street and hiway. Lots of power available even when going 70mph, punch it the little 4.0 just pulls to the max. I have the speed limiter set at 120, and it will pull hard all the way past 110mph. If you have the automatic, you can deselect over-drive manualy, then using the engine to brake/slow down from the higher speeds, saves your brakes from over heating too. With the 3.73's your final drive ration is not in the overdrive range, someone here posted the math and showed the results, just don't remember who, sorry. I'm getting about 19mpg, mix city/hiway driving with a heavy foot
I had ford do the install, specs call for backlash of .010, which is tight. I have some gear noise, but it's not as bad now, gears wearing in is slow with the synth oil ford uses, plus most of the 3.73 gear sets are made by motive for ford racing specs, I think these are more subject to gear whine. Some one here on forum used a set of 3.73 gears out of a ranger pickup from salvage yard, if I was to do this again, thats what I would look into, those are production gear sets, allready worn in and probably very good bargin.
Have fun and drive safe.
I have noticed dramatic improvement in drivability both street and hiway. Lots of power available even when going 70mph, punch it the little 4.0 just pulls to the max. I have the speed limiter set at 120, and it will pull hard all the way past 110mph. If you have the automatic, you can deselect over-drive manualy, then using the engine to brake/slow down from the higher speeds, saves your brakes from over heating too. With the 3.73's your final drive ration is not in the overdrive range, someone here posted the math and showed the results, just don't remember who, sorry. I'm getting about 19mpg, mix city/hiway driving with a heavy foot
I had ford do the install, specs call for backlash of .010, which is tight. I have some gear noise, but it's not as bad now, gears wearing in is slow with the synth oil ford uses, plus most of the 3.73 gear sets are made by motive for ford racing specs, I think these are more subject to gear whine. Some one here on forum used a set of 3.73 gears out of a ranger pickup from salvage yard, if I was to do this again, thats what I would look into, those are production gear sets, allready worn in and probably very good bargin.
Have fun and drive safe.