I have wanted to do this for a long time, and now i really want to fix the lag i have with the stock gears. I have a 2001 7.3 auto with factory 3.73 gears. the truck is lifted on 37s, so obviously i am loosing quite a bit here.
Im told that 4.56 will bring it back to stock, so i am thinking of going to a 4.88 for a little extra torque multiplication. anyone have a similar setup?
also, has anyone done this themselves? I consider myself to be a fairly competent mechanic, but i only do it part time and have never done a gear swap. any opinions along the way here?
Im also thinking of putting in a factory limited slip in the rear. (cant afford a locker, or so i think) any opinions here?
I did my gears with a buddy of mine, not overly difficult just have to be accurate measuring to set them up properly. Set them up wrong and you will run into issues.
Thanks DC, so if i want to get a little more gear than stock, wouldnt the 4.56 be a little peppier than the 4.30s? I know we dont have a lot of RPMs so i cant go too steep.
thats the problem i have, I do use the truck for commuting about 30 miles a day, so fuel economy is a slight issue. however. i might go to bigger tires later on in life, and the wife and i are considering a camping trailer. the truck is already on its 2nd transmission, so i want to gear up and help the truck out. i also want to gain a little performance in the process.
I have towed my car with the truck before, and an occasional u-haul trailer. probably never more than 5000 lbs. but due to the gears, if i tow at 65 mph or less, the truck will shift out of OD on hills on the highway. when i speed up to about 80, the truck would drive fine, but thats a little faster than i want to go with a trailer with no brakes
sorry for the long post, but im sure some of you guys can understand, i only want to do this work once (unlike the engine that came out 3 times now )
so it sounds like if i stay with 37's i will gain a little with 4.56. thats what i want. and if i go to 38s then im still in the stock range. but if i decide to go even bigger with the tires, then im going to have to do it again.
so does anyone have some links to how to manuals? what about manufacturer? im thinking ford gears then manybe re-using shims (ofcourse i will still check them). and what about the ford limited slip for the rear, good or bad?
It's going to be a give and take no matter what you do. From the other opinions on here, there is no "magic" ratio. From previous threads I've read here, 4.30 seems to be the most suggested ratio by far for 37's and 38's. It gives the truck longer legs on the highway, while improving the reponse at the lower speeds.
Another thing to think about is if you decide to go 4.56's because you can add 40's on down the road, you'll be running 100-200 (I'm guestimating) more RPM's at a given highway speed while the truck is on 37's vs 4.30's. That is extra wear on the motor in the long run.
yea, very true. like you said, there is no majic answer to this, unfortunatly. I just dont want to go through all the work and end up not gaining enough. on the other hand i dont want to put way too much gear in there. I cant believe that 1 inch in tire size makes that much of a gear change.
does anyone have a link to one of those gear ratio calculators???
i dont tow too often, but that might change soon.
i commute about 70 miles round trip daily, but if i can stay close to what i have now for mpg im ok with that. i figure the gain from correct gearing might offset the added rpm.
as for off roading, i used to a lot, but after blowing the engine, i need to put that on hold for a while, maybe a long while
As far as the install goes it's not that hard. I did mine and it was my first gear swap and have never had any trouble. I would recomend calling Randy's Ring and Pinion. I used the Yukon gears and install kits and they seemed to be very good quality. Also you can get all the tools you need from Randy's. Just make sure you take your time and you should be ok.
nice, glad to hear. maybe i can buy your experience with beer???
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