gear ratio changing questions

[Wagoneerlover]

Ok all I am still going to swap in the 700r4. I thank you all for your help and am not very well versed on gear ratios and rear ends. here is my question to you all. Making the gear ratio lower does what?

From what I am reading it seem sas if it would make the rig better for towing etc and the engine would work harder. however the overdrive would kill this and make the engine more efficient. Is that correct?
A higher gear ratio would develop better speed but be less good for towing and off roading? is that correct?

Secondly I have an np 229 transfer case and if I change the gear ratio would that include the front axle too? Would I need to adjust the front axle gear ratio as well? I have the 2.72 gear ratio so right now the swap is useless unless I change the gear ratio. also how difficult is it to change the gear ratio? is it very difficult and best left to a shop or is it something that one can do at home with a few buddies and some pizza? what does such a change entail? can we just remove the gears and put in new ones or do we need to swap the whole axle? and lastly what would be a good ratio to change the axles to to make the 700r4 with overdrive perform well (within the power band of the egnine?

I thank you all for your help and your responses will help me significantly with my decisions.

[joe]

You've pretty much got it. The lower the gear ratio(higher numerically) the better off you'll be for towing. If you plan to build a tow rig with OD I'd go at least 3.73 gears or even 4.10's. With an OD you'll still have a decent final drive ratio for normal hwy driving....about what you have now if you swap to 3.73's and about 3.00 if you use 4.10's(figuring most OD gears are around 0.73:1 or so). You won't be towing in OD anyway but rather in high gear. 4.10's with an OD trans would be a nice set up. For normal driving you wouldn't lose any mpg's and maybe even gain one or two. I personally believe the stock 2.73 are too high for best mpg's on these things.
Yup, you'll need to change out both front axle gears and carriers. To have a shop do it plan on $1200-$1500 depending on the shop rates in your area and what parts needed(maybe new spider gears etc). You can do it yourself but you'll need a few special tools and it "is an exact science" and time consuming. Close-enough won't cut it here, the gears need to be set up correctly. Read the section in the factory shop manual carefully and then be honest with yourself and decide if you're up for the task. Keep in mind it won't be done like the pics in the book where everything is on a work bench. You'll be doing it upside down on your back undernearth the truck. It's not really something you want to tackle as your first mechanical/learning project. If you're paying shop time to swap both R&P's, trans cost, adaptation, possibly tcase, driveshafts etc you can end up spending some serious money pretty quick. Time to decide if an old Wag is worth it or just buy a used rig that was set up/designed for towing already.

[fulsizjeep]

With 2.72 gears now, you can go to 3.73 without changing the carriers. That's what I did... smile.gif I had a friend help me who had done it before. Would not attempt it on my own if you never done that before. That is the best mod I have done so far for towing and trails. :cool: