Question about gearing?

[97awdx]

What is the lowest gearing I can put in the front and rear of an 05' ST. I called Yukon and Randys Ring and Pinion, they said 4.55. Anyone know of anything lower?

 

[97awdx]

What is the lowest gearing I can put in the front and rear of an 05' ST. I called Yukon and Randys Ring and Pinion, they said 4.55. Anyone know of anything lower? Already tried the ST section, but I guess no one knows.

 

[AMMO_HOOAH]

Do you know what kind of axles you have? I'd be willing to bet that if Randy's told you that's the biggest then they're probably right.

 

[RangerX]

That's not low enough? How low do you want to go?

 

[becker69]

It shouldn't really matter that the R&P's are for an ST vrs. an Ex. I would have thought at least 4.88's or so, as 4.56's are common. I honestly don't know, but it'd be the same set as for an 8.8 and the D35 IFS. But maybe the IFS limits how low.

Out of curiousity are you planning on running a tire larger than 37's?? OR what is the reason to regear so low? I'd hate to see how long the IFS would last with gears and or tires for that

 

[97awdx]

The rear is a 8.8, Im not sure what the front is, Dana 30? The truck is a gutless wonder with 33's and im afraid of doing damage to the tranny towing a 5000 lb trailer.

 

[97awdx]

The problem is that with 33's the truck cant get out of its own way. Any other sugestions would be appriciated.

 

[IZwack]

Run 4.56s/4.88s and call it good. And the front is a Dana-35 .. I think Randy's Ring & Pinion also refers to this as the "M35".

 

[97awdx]

Run 4.56s/4.88s and call it good. And the front is a Dana-35 .. I think Randy's Ring & Pinion also refers to this as the "M35".

It wont hurt it when in 4wd? I dont need to explode my t-case.

 

[MountaineerGreen]

The 5.0 with 33's and 4.10's is just right- anything lower will suck gas like crazy. I pull a 5k travel trailer no problem with 33's and 4.10's.

 

[IZwack]

It wont hurt it when in 4wd? I dont need to explode my t-case.

No you wont .. see the torque multiplication is done at the ring and pinion which means the added torque is after the differential's carrier, not at the transfer case, driveshafts, or transmission.

The 5.0 with 33's and 4.10's is just right- anything lower will suck gas like crazy. I pull a 5k travel trailer no problem with 33's and 4.10's.

He lives in Scranton, PA -- between the mountains of the Catskills and the Alleghany, killer inclines there. My 7.3L PSD aches when I head up that area with something in tow

 

[97awdx]

No you wont .. see the torque multiplication is done at the ring and pinion which means the added torque is after the differential's carrier, not at the transfer case, driveshafts, or transmission.

He lives in Scranton, PA -- between the mountains of the Catskills and the Alleghany, killer inclines there. My 7.3L PSD aches when I head up that area with something in tow

Even still if you have 4.10 up front and 4.56 in rear. For every 1 time the front tire revolves the drive shaft spins 4.10 times; for the rear every 1 time the tire revolves the drive shaft spins 4.56 times. So if one shaft is 4.10 times going into the T-case and one shaft is 4.56 times going into the t-case somthing has to give. Just my view, any thoughts? Its a 4.0 Sport Trac I need gears for, not the 5.0 X. Hills around here are killers

 

[IZwack]

I didn't mean for you to run two different gear ratios.... where did you get that idea from?

 

[rookieshooter]

The ring gear on a D 35 front axel is smaller dia. then the rear 8.8. It's just too small a diameter to get too many teeth with any amount of strength. I'd stay in the low numerical 4ish range.

 

[becker69]

Even still if you have 4.10 up front and 4.56 in rear. For every 1 time the front tire revolves the drive shaft spins 4.10 times; for the rear every 1 time the tire revolves the drive shaft spins 4.56 times. So if one shaft is 4.10 times going into the T-case and one shaft is 4.56 times going into the t-case somthing has to give. Just my view, any thoughts? Its a 4.0 Sport Trac I need gears for, not the 5.0 X. Hills around here are killers

As has been said, If you are really wanting to regear (say spending the ~$1500 or so depending on the shop), go with the 4.56's and at least you won't be running 4600 rpms @ 35 mph on the street when you're not towing . Also maybe consider some duckets into a good intake and exhaust to get back a little more bottom end torque (or even headers on the 4.0). Maybe a good compromise between aftermarket bolt ons and gearing will help you out... just make sure you run the same gears front and rear and have a decent tranny cooler, and you should be fine (as far as tranny concerns go).

 

[97awdx]

Thanks for everyones help. Do headers help with low end power?

 

[MoabB2]

Thanks for everyones help. Do headers help with low end power?

haha! Yes!

Go with the Torque Monster Headers, they are built to generate low end torque.

 

[rookieshooter]

Along with the headers you might want to think about your exhaust pipe diameter. On my B2 I could run 3 or 2 and 1/2" pipe. I opted for the more low end torque 2 and 1/2 dia.