gearing [Archive] - ItsaJeep.Org Forums

Tomster

03-21-2005, 01:05 PM

Josh:

It would depend on what size tires your Jeep had from the factory. Did it have the 30" tire package? Your Jeep is a Sahara, right? I THINK they all had the 30" tires.

It's a straight ratio. If you go up 10% on tire diameter, like from 30" to 33", then you go up 10% on gear ratio, like from 3.73 to 4.10.

That gives you your orignal RPM for a given speed. Since you will use your Jeep for daily transportation, maybe 4.10 is as far as you should go, but 4.56 might be the way to go for mostly trail use.

Bill, just cause you started with those 3.07 gears doesn't preclude you from going to 4.10's for the 33s. You have the same 4.0 L engine, so the 4.10's will work fine. That will give you more than the original RPM for a given speed, but not so high RPM as to be a problem.

I can't understand why they even put the 3.07s on Jeeps to begin with! Yuck! The 4.0 L, although a good engine for low end torque, is not powerful enough for that kind of gearing.

Tom

BillM

03-21-2005, 01:12 PM

Oh I know Tom. to get me back to the original spec I would go to a 3.6? something gear which they don't make. I plan on the 4.10's myself. wish someone had the 4 cyl diffs with stock gears they would like to get rid of. Hint Hint

Don

03-21-2005, 01:14 PM

Hey Guys: I think this page will answer most of the questions. CLICK HERE (http://www.4lo.com/calc/geartable.htm) for tire size / gear ratio calculator.

Josh

03-21-2005, 01:57 PM

i was planning on 4.10 but wasn't sure if i should do more or less, or leave it the same

DavidC

03-21-2005, 02:22 PM

I agree with tom 3.07's are a challenge to wheel with. I know as I had them and ran 31" tires. I swapped to a D44 that came with 3.73's last year and had the front gears done by a friend and it was much better. However I was supposed to have my Jeep back on friday with 4.10's and ARB's(I wanted selectable lockers so I figured I regear again!$$$)but it is not finished as of today.If this goes on any longer I'll have to change my sig. as I was so excited and jumped the gun by including this mod.

You might want to check with Mikea as he has a Rubi and I believe is running 33's. If he hasn't regeared he'd be at 4.10 as that is what is stock.

Keep in mind he also has the 4:1 transfer case.But at least you'd get a feel for the on road performance.

David

Don

03-21-2005, 03:45 PM

Hey David,,, watch what you say about 3.07's..... I have these gears and I am running 33 inch tires. Can we say 3.07's suck big time.... /ubbthreads/images/graemlins/td.gif Bill and I have been talking about doing the Ford 8.8 swap, /ubbthreads/images/graemlins/tu.gif or for that matter, any swap would be an improvement from 3.07's. /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif
Bill brought up a good point about a 4cyl. comes stock with 4.11's,,,,,, personally, if I am going to do all the work to swap out an axle, I want to swap to something better than a Dana 35 /ubbthreads/images/graemlins/td.gif

DavidC

03-21-2005, 04:39 PM

Don,

I didn't want to dis anybody runnin 3.07's especially on 33"s. I have an extra set of used 4.10's from a D30 and D44 if you would like em let me know. I had a friend who also regeared to 4.88's and he gave them to me free.When I went to change gears this past week the shop that is doing the work would not warranty their work with used gears. Since I was already spending money to put ARB's in as well, I didn't want to have any problems so...went with new gear$$$$.

Now just if they could get it done!!! I'm suffering withdrawl's.

David

scrambled

03-21-2005, 07:05 PM

I guess the question you should be asking yourself is how much trail use it is going to have. I ran 4.10's with 31's for years which were a little to low on the street but great on the trail. Now I run 33's with those 4.10's. They would be great for the street but they are a little too high for what I care for on the trail.

Tomster

03-21-2005, 07:20 PM

Remember, gearing is not just for accelerating. Gearing is important for holding the Jeep back on steep descents. It is also important for being able to go REAL slow without feathering the clutch and burning it up.

A 4:1 low range, like the Rubi's have, would be nice, huh? That way you can have good highway gearing and still have a nice, slow crawl speed.

Tomster

BillM

03-21-2005, 07:27 PM

I agree 100%. 4:1 would be great. I did see an Atlas II that was 10:1. Just about $10,000. Anyway, I will be upgrading to 4:10 and lockers soon I hope.

gmbtj

03-21-2005, 07:30 PM

10:1!!!!!!!!!!!!!!!!!!
http://www.columbusracing.com/ubb/graemlins/eek2.gif
****!!!!!!!!!!!!!!!!!!! That puts a whole new meaning to 4-low!!!!!!!!!!!

Don

03-21-2005, 07:32 PM

David, you were not dis anybody. The 3.07 suck /ubbthreads/images/graemlins/td.gif I can't do the gear job, so there doesn't seem to be a real reason (unless I am missing it) reason to pay a professional major $$ to install gears in a diff that I don't want to keep. I have the D35 in the rear...... wish it was a D44. /ubbthreads/images/graemlins/grin.gif
My 4x4 shop said they would only use used gears as a "Trail fix"...

BillM

03-21-2005, 07:34 PM

Could you imagine how slow 10:1 would be even with 3.07's LOL. No dis here David. Would go with the 8.8 for sure but can't decide on whether to go fullwidth or not.

Don

03-21-2005, 07:39 PM

[ QUOTE ]
Could you imagine how slow 10:1 would be even with 3.07's LOL. No dis here David. Would go with the 8.8 for sure but can't decide on whether to go fullwidth or not.

[/ QUOTE ]

Dang guys....... educate me,, what is "Fullwidth" and what is the other option?

gmbtj

03-21-2005, 07:47 PM

Umm, Don i wouldnt recommend putting those gears in urself unless u have the special dialing tools that measure u backlash and pinion angle and everything perfectly. That is a job that i will never be willing to tackle, but i plan on dropping a bigger engine and new rear axle myself with the help of my friend.

Don

03-21-2005, 07:50 PM

[ QUOTE ]
Umm, Don i wouldnt recommend putting those gears in urself unless u have the special dialing tools that measure u backlash and pinion angle and everything perfectly. That is a job that i will never be willing to tackle, but i plan on dropping a bigger engine and new rear axle myself with the help of my friend.

[/ QUOTE ]

Don't worry Gumby,,, I would never attempt to do gears. However, if I found a nice 8.8 complete, I would attempt to do a swap myself. However, I now have this "FULLWIDTH" issue to deal with.... thank you very much Bill /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif

gmbtj

03-21-2005, 07:54 PM

Bwaa-hahaha. /ubbthreads/images/graemlins/grin.gif

DavidC

03-21-2005, 07:56 PM

My Jeep is usually loaded down with gear and my family when we travel to various off road places so 4.10's with 31" tires will be an asset on those long uphill roads. Also, it is not my DD so I can kinda build it for offroad. I agree with Tom that having a 4.1 tcase would be great 10.1 I can't even imagine.

Don,

Full width- think truck width axle vs our narrow Jeep axles.Full width adds stability and some like it because with more lift its more stable then narrow track.

HTH.

David

DavidC

03-21-2005, 08:01 PM

Don,

If your thinking 8.8 check this out.

http://www.ok4wd.com/product.asp?id=547

Don

03-21-2005, 08:15 PM

sooooooooo,,,, is an axle out of an Explorer considered a "Fullwidth" ??? I also notice that it says the 8.8 is NOT Compatible with ABS Equipped Jeeps. Why? Is this a major problem?

BillM

03-21-2005, 08:18 PM

Man that is alot to pay for them to weld the bracketry on for ya. $700!!!!!!!!!! Good lookin setup though.

Don,
You just need to get a GM 14 bolt for the back and a D44 front from an F250 and go fullwidth. LOL

BillM

03-21-2005, 08:21 PM

[ QUOTE ]
sooooooooo,,,, is an axle out of an Explorer considered a "Fullwidth" ??? I also notice that it says the 8.8 is NOT Compatible with ABS Equipped Jeeps. Why? Is this a major problem?

[/ QUOTE ]

No the 8.8 from an Exploder is not fullwidth. It is actually shorter than your stock diff by 5/8" on each side. I have seen an 8.8 that came from an F150 and that would be fullwidth. I found some 8.8's on ebay that came with the ABS ring in the center unit so there might be a chance to get the ABS working again.

Don

03-21-2005, 08:30 PM

I honestly can't remember if I have ABS or not on my TJ. I'll have to look at the build sheet tomorrow (its at work).
I knew that about the 5/8 inch.. just didn't have my brain turned on. How much wider than stock D35 is an axle out of a F150. Also, if I remember, doesn't the 8.8 out of a Mustang have fewer splines?

BillM

03-21-2005, 08:32 PM

[ QUOTE ]
How much wider than stock D35 is an axle out of a F150. Also, if I remember, doesn't the 8.8 out of a Mustang have fewer splines?

[/ QUOTE ]

An 8.8 can be 27 or 31 spline. You can change the LS unit to either or.

Don

03-21-2005, 08:36 PM

How would I know how many splines without pulling the axle?
Change the LS to what? Educate me, please.... /ubbthreads/images/graemlins/grin.gif

DavidC

03-21-2005, 09:15 PM

Don,

Stock D35 27 spline
Stock D44 30 spline
8.8 31 spline

Don

03-21-2005, 09:22 PM

Bill said that a 8.8 could have 31 splines, or 27.... how would I know the difference without pulling axles.. What type of Explorer or whatever would I be looking for to get the 31 Spline? Am I correct that an Explorer Axle will be 60 inches from backing plate to backing plate?

Matt

03-21-2005, 09:28 PM

The explorer 31 spline. the ranger is 27

Don

03-21-2005, 09:36 PM

Matt: did you do the 8.8 swap yourself? If so, how hard was it? How hard to do swap and mounting brackets for a TJ?Where did you find the 8.8? What are important things to look for when shopping for an 8.8? Do you mind me asking how much $$ in the swap, and in the re-gear? If you prefer not to answer, that's okay, or you can PM me.

DavidC

03-21-2005, 09:37 PM

Don,

Why not just get a Jeep D44 from Jeepsareus? it's a direct bolt on and you can reuse your existing brakes and such.

DavidC

03-21-2005, 09:43 PM

M.O.R.E and Rubicon Express have the mounting brackets that can be welded on an 8.8 so that it will bolt into a TJ.

You will also need to change your e-brake cable I believe.

I went D44 as it was an easy swap and I wanted to run my stock Jeep rims. Also, I know I will get flamed but.. the 8.8's use C clips like a D35 to hold the axles in. I know that these are very robust axles but I didn't wan't to deal with any C clips if I were swapping axle shafts.

Don

03-21-2005, 09:45 PM

[ QUOTE ]
Don,

Why not just get a Jeep D44 from Jeepsareus? it's a direct bolt on and you can reuse your existing brakes and such.

[/ QUOTE ]

Because, I can purchase a Ford 8.8 for about $300 from a local bone yard, do the bracket kit ($100), plus lots of labor, then pay professional to Re-gear it IF NEEDED as I understand that some 8.8 have 4.10 gears, and limited slip.... IF I could find an 8.8 with 4.10's and the limited slip, then I would only need to pay a professional to regear the D30 in the front. Don't think I could find a D44 for anything close to this $$$

scrambled

03-21-2005, 09:51 PM

$300 bucks How about this. He is only like 10 minutes form my house. 3.73 gears and LS. You would be in business and I might be able to swing it close to your way if you want it.

http://www.mn-jeep.com/forum/showthread.php?t=1478

DavidC

03-21-2005, 09:52 PM

I agree...an 8.8 would be less in the long run if you could find one with 4.10's

I'm not handy with a welder so I ruled that out.

David

BillM

03-21-2005, 10:36 PM

I am watching an 8.8, 4.10, LS, with the complete disc setup on ebay now. Last time I looked it was at $45 or so...LOL We'll see.

Josh

03-22-2005, 12:28 AM

i'm planning on the 4.10 and eventually going with d44 and arb, but that is way down the road around the time i hit the lottery

Don

03-22-2005, 06:18 AM

[ QUOTE ]
$300 bucks How about this. He is only like 10 minutes form my house. 3.73 gears and LS. You would be in business and I might be able to swing it close to your way if you want it.

http://www.mn-jeep.com/forum/showthread.php?t=1478

[/ QUOTE ]

I would prefer 4.10's.. Maybe I should go to Ebay and bid against Bill /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif Bill if you find another 8.8 diff like what you are bidding on,, yell at me. Scrambled, if you find one, where transportation isn't an issue, I'll jump at it /ubbthreads/images/graemlins/tu.gif BTW, have many road miles are you from Louisville, KY?

Don

03-22-2005, 06:20 AM

[ QUOTE ]
I agree...an 8.8 would be less in the long run if you could find one with 4.10's

I'm not handy with a welder so I ruled that out.

David

[/ QUOTE ]

David, I am not a welder either. However, my Daughter's BF is in welding school to become a Certifide welder... so I figure sooner or later, he will be able to weld whatever I need /ubbthreads/images/graemlins/grin.gif

Don

03-22-2005, 09:20 AM

[ QUOTE ]
$300 bucks How about this. He is only like 10 minutes form my house. 3.73 gears and LS. You would be in business and I might be able to swing it close to your way if you want it.

http://www.mn-jeep.com/forum/showthread.php?t=1478

[/ QUOTE ]

Scrambled, I just reviewed the Gear Ratio Chart CLICK HERE (http://www.4lo.com/calc/geartable.htm) and confirmed that 3.73 will be too low with my 33's. I really need 4.27's or higher, but 4.10 are close enough /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif /ubbthreads/images/graemlins/hee.gif

scrambled

03-22-2005, 09:38 AM

Yeah I hear ya. I will keep an eye out up here because those axles pop up all the time. I stayed with 4.10's because all I had to do was buy them for the back cause I already had them for the front. I tore the rear out because I had to prove that I could do a burnout on dry pavement and smoke all four tires at the same time. I didn't know I had a problem until the next day when I tried to drive it to school and the rear tires didn't want to move very well. Was it worth the $50 bet? Maybe not but is was cool as sh*t to see. Those BFG M/T's were a hummin

Don

03-22-2005, 11:09 AM

Fred,,,, you are correct, 3.07 are not on the chart. I think the 3.07's only work with 26 inch or smaller tires. Basically, if you have anything bigger that a kids toy wagon, 3.07 SUCK. /ubbthreads/images/graemlins/td.gif

Scrambled,,, keep your eyes open for a 8.8 with 4.10's or higher. That way, I'll have to change gears in front. Then some day way way in the future after I win the lottery, I'll change front and rear to 4.88's. Can we make that noise that the Toolman makes on that TV show?? /ubbthreads/images/graemlins/grin.gif

Don

03-22-2005, 11:14 AM

[ QUOTE ]
Acording to your chat 3.07's aren't even ON THERE! **** 3.07's REALLY suck.....WAAAAAAAAAAAAAAAAA.....I want 4.11's NOW!

[/ QUOTE ]

Fred, I forgot to say in my last post that I am running 3.07's with 33 inch tires... I know all about how bad those 3.07's SUCK. /ubbthreads/images/graemlins/td.gif I watched a buddy's Jeep just idle up a hill, when I had to give it some gas and pray.
Gears were the difference. Waaaaaaaaa, I want new gears!!