What gears do i need? SLOWWWW!!!!

[StimmyRanger]

So i just put a 4" spindle , 2" shackle lift with 33" tires on my 2000 Ranger 2.5 2WD. Around town shes ok, but on the highway shes SLOW... i can barely get out of 3rd/4th gear going 55mph. I do live where the roads have inclines and declines everywhere so shes always struggled but not nearly this much.

My door has code 87 which ive discovered means i have a 7.5 4.10 diff. Theres no tag on the diff so who knows. Before finding that out i read that 4.10 or 4.56 would bring her back to life. But i already have 4.10's and shes shit on the highway, would 4.56 really make that big of a difference maybe theres a better ratio? I will be mainly on the highway with mild off road, just to take the dirt bike out and go shooting. I got quoted $750 parts and labor and lets just say i cant throw money that easy right now so im trying to make sure its worth it.

 

[Dirtman]

You've gone up 5 inches in tire size on a motor with 117hp.

You have 4.10 gears now, the tires have effectively reduced that gear ratio to about 3.40. You would need 4.94:1 gears (those don't exist, just the equivalent ratio) just to get it back to stock overall ratio.

Since 4.94 gears don't exist you basically you need 5.13 gears, but 4.88's would probably be "OK", 4.56 will probably still leave it pretty sluggish. But even 4.56 gears require grinding to fit the stock rear so I don't even know if anything bigger is available for the 7.5" rear.

 

[StimmyRanger]

Oh wow, good thing I came here first. Life saver! I will look into those.

 

[ericbphoto]

Yup. 4.88 or 5.13 gears.

 

[Dirtman]

Nevermind you can still use a notched center pin with 4.56 gears, you only need to grind if you're using a solid center pin so forget about that part unless you have a locker/LSD. I had a brain fart.

 

[StimmyRanger]

@Dirtman @ericbphoto okay so would you know the difference between 4.88 and 5.13. As in the pros and cons of one vs another to help me decide.

 

[Dirtman]

@Dirtman @ericbphoto okay so would you know the difference between 4.88 and 5.13. As in the pros and cons of one vs another to help me decide.

4.88 will put you slightly UNDER the stock gear ratio, 5.13 will put you slightly OVER the stock gear ratio.

So 5.13 will make it peppier than stock but raise the RPMs on the highway so you'll loose some fuel efficiency and max cruising speed while 4.88's mean it'll be a bit sluggish around town but cruise better on the highway. HOWEVER... Considering you have a 4 cylinder I'd be inclined to go with the 5.13 gears since you've not only changed the ratio, you added a bunch of weight from those big tires so you'll need all the help you can get to keep them spinning.

Again I do not even know if those gears are available for your differential though. They make them for the 8.8 but I do not know about the 7.5.

 

[racsan]

Id get a 8.8 & regear it to the 5.13’s , youll at the very least gain bigger brakes, and with a 8.8 theres the possibility (with a explorer donor axle) youd gain disc rears. You still need to get stopped and youve added 4 big flywheels (tires) that are harder to get stopped than the stock size were.

 

[sgtsandman]

Based on my previous experience with a 1998 with the 2.5, I would go with the 5.13 gear. The engine, while generally rock solid, is short on power and needs all the help it can get. To get back to the performance you had before, that would get you close to the revolutions you had before and power output. This is assuming your original tires were 27" like mine were. If that is the case, the 27" tires and 4.10:1 gear would put you at about 3325 RPMS. With the 33" tires you have now, 5.13:1 would put you at 3395 RPMS. A little higher but with the heavier tires you have to get rotating (more mass to get turning), you will probably appreciate it.

Like mentioned above, going with an 8.8" axle with bigger brakes would probably be a good idea. Those heavier tires are going to be harder to stop spinning. No Ranger axle came from the factory with that low of a gear. So, you'll be looking at a gear swap regardless. I'm not even sure if you can get a 5.13:1 for a 7.5" axle anyway.

This was the chart I used to get my numbers: https://www.therangerstation.com/how-to_pages/gear_ratio_tire_size_chart.shtml

 

[rubydist]

Since the 2.5 could barely get out of its own way in stock form, and since you have put those huge tires on it, it may make more sense to install an engine with some actual power to it.

 

[snoranger]

Might I recommend...

Boost.... lots and lots of boost.

 

[Fast Eddie]

How to identify 8.8 vs 7.5 rear? Are there physical characteristics that distinguish?

'04 2wd M5OD on a 4x4 chassis with tow kit. Will attempt max tire size of 31 w/o lift on stock 15" rims - supposed to work.
TIA

 

[ericbphoto]

Should be a tag on the axle. There is also an axle code on the sticker on the driver door jamb. Instructions in the tech library for interpreting the codes. Also a great article on the physical/visual differences between them.

Axle Tech - The Ranger Station

DISCLAIMER: Activities and vehicle modifications appearing or described at The Ranger Station and it’s pages may be potentially dangerous. We do not endorse any such activity for others or recommend it to any particular person – we simply describe the … Continued

www.therangerstation.com

 

[Fast Eddie]

Should be a tag on the axle. There is also an axle code on the sticker on the driver door jamb. Instructions in the tech library for interpreting the codes. Also a great article on the physical/visual differences between them.

Axle Tech - The Ranger Station

DISCLAIMER: Activities and vehicle modifications appearing or described at The Ranger Station and it’s pages may be potentially dangerous. We do not endorse any such activity for others or recommend it to any particular person – we simply describe the … Continued

www.therangerstation.com

Hot linked. Thank you.

Edit: Axle code 97 - SAAAAAWEEET. I can run 5:13 in the existing pumpkin. I'm a happy man.

97

open 8.8″

2750

4.10

 

[sgtsandman]

'04 2wd M5OD on a 4x4 chassis with tow kit. Will attempt max tire size of 31 w/o lift on stock 15" rims - supposed to work.

It will. I did the pre-2008 mod in order to do the same thing on my 2011.