97 TJ

A little teaser on things happening:

[IMG]https://www.frontrange4x4.com/forums/attachment.php?attachmentid=52124&d=1626123858[/IMG]

I'm looking ahead to see what I need to plan for and found out my stock gearing says 3.07 on the differential tags... Can we get an "F" in the chat for my diffs?

[IMG]http://myjeeptj.com/wp-content/uploads/gear-ratio-to-tire-size-chart/gear_ratios.jpg[/IMG]

Rocking 3.07 and 33's puts me pretty far out from where I assume it should be? It's on 235/75/r15 (29in tire roughtly, 28.9 exact) and it drives just fine. It looks like there's only a 300rpm difference at "final drive" for the numbers on this chart...

Either way it looks like it's going to perform okay on the road, interested to see how it will behave on the trail. For what it's worth I drove this home as it was rocking 33x12.5s and it felt tired like I was having to row the gears a lot. I'm not sure of the path forward yet but most paths are leading toward regear/locker sooner than later.

F

(I don't think many people on this forum are going to get that reference Schmitty lol)

Something to consider... What reduction gearing you have for low range (do you plan to change it???).


Me, I have 4.10's with 35's - but I have 4:1 (teralow kit) low range. This combo suits me just fine for trail use (most of the time I'm in 2nd / 3rd 4th with a bit of first and rare time in 5th). If I had stock low range, I'd be hurt'n on the trails. My street gearing is "about right". Only on street steep uphills do I see myself dropping one or for a short distance two (steep grades on I-70). I don't tow.

As for the "F" - went looking on the chart for it - so my assumption is fail.

F means to pay respects. From a video game

Do people tend to run lower than stock gearing (after correction) when they re-gear just to help with the lower power at this altitude?

[QUOTE=Steve-O;343832]F

(I don't think many people on this forum are going to get that reference Schmitty lol)[/QUOTE]


hey we're not that old!

I'm surprised to hear you have 3.07. Maybe that was a feature of earlier TJs? My build sheet calls out 3.73 gears for my non-Rubicon LJ. I just assumed 3.73 was standard on TJ and LJs. Does your build sheet say 3.07 also?

Edit: [url]https://wranglertjforum.com/threads/wrangler-tj-stock-specifications.71/#post-181[/url]

Looks like many different gear ratios are factory standard. I'm surprised by the wide variety here.

[quote=rckymtnt4r;343831]found out my stock gearing says 3.07 on the differential tags[/quote]

Oof...and I am with Trent - a bit surprised they offered that high a gearing....but is it an automatic? An ol' rule of thumb is that for calculating CR and figuring out gearing needs, the torque converter acts to help crawl ratio by about 50%. In other words, for a manual, take the axle gearing x 1st gear x low range reduction....somewhere around 40 becomes reasonably functional for most easy and moderate trails around here, and near 60 is pretty sweet for most of us running 33-35s and difficult trails, albeit maybe not full-on rock crawling. For an automatic, you can take the same calculation and then multiply by 1.5 to get the equivalent crawl ratio....this is typically noted in older automatics (3 and 4 speed) in that their 1st gear is quite a bit higher than manuals, but the torque converter offsets that high 1st gear and also allows for higher axle gearing for highway efficiency without sacrificing too much performance.
For a manual, I'd say 3.07 is too high, but it might be doable in an automatic...of course, the good news, if you know you want the 33s, mount them up, drive it around, and if you decide its not performing well enough, then you can change the gearing....or maybe you'll find out its not too bad and just keep driving it....my first cj (1984 cj7) I ran 33s with a tired 258 I6 - it probably should have been re-geared (IIRC I think it ran 3.31?), and it was a bit of a dog on the street. But the stock 3:1 D300 transfer case reduction and the 4:1 1st gear (about the only redeeming quality of the weak T5 transmission), the off road crawl usage was plenty good. Guessing you may find something similar...

He has the same drive train as my Xj (ax-15 manual tranny) my Xj has 3.07 gears also, trust me 33" tires and that gearing is not going to work at all. Especially on the trails. I remember trying to climb the easy side of Slaughter House Gulch. After that trip I immediately went looking for a set of 31"s (that better but still no Bueno). 4.56 is really the best gearing for 33"s and this drive train.
Oh I'm assuming he has a 4.0?????

[quote=Jim;343834]What reduction gearing you have for low range (do you plan to change it???).[/quote]

I'm not sure but it's not what the Rubicon has with it's 4:1 ratio or whatever... I do plan on making a tiny camper trailer or teardrop at some point so [I]some[/I] ability to tow a light load must be retained.


[quote=TDash;343841]hey we're not that old![/quote]

34 :D


[quote=open_circuit;343844]I'm surprised to hear you have 3.07.[/quote]

I am too, I pulled the numbers from the diff tags... I went to check and [I]womp womp[/I] 3.07 was stamped.

[B]For reference: [/B]The TJ has the 4.0 with the AX15 5-spd.


[quote=JandDGreens;343851]4.56 is really the best gearing for 33"s and this drive train.[/quote]

This is the plan. I went digging in the TJ forums and found [I]lots[/I] of folks pushing for 4.56 gearing at 33in tire size.

Rusty's has a "regear special" that's looking more attractive than a cup of water in the desert right now: [URL]https://www.rustysoffroad.com/jeep-driveline-driveshaft/jeep-ring-pinions/jeep-ring-pinion-gear-specials/rustys-gear-special-00-01-xj-97-06-tj-97-98-zj-d30-std-front-d35-rear.html[/URL]

so maybe I'll prioritize the regear before upgrading axles...

This is escalating quickly.

3.07 was standard with the 4.0/AX15. That transmission doesn't have much overdrive. So it doesn't need short (higher number) gears, especially with the small stock tires. 33s are a significant change in tire size and a regear is appropriate. And going with more gear than you need to compensate for the tires would be a good idea.

All of the 4 cylinder TJs come with 4:10 gears, you can regear cheaply that way. I did the front axle in my last Jeep that way, cost $150.00 for the whole axle.

Getting all that done will not be cheap...

Edit: The goal right now is to get out and play a little on some trails and use it as a camping vehicle. I may go with 31's in the meantime, bring it down to a 2in lift and save for "the big axles" at a later time. Trying to keep this low-budget currently and projects like this can get out of hand quickly. I'll keep an eye out for some 4.56 gears or some 4cyl axles.

Update: Sourced some 4.56 gears for the D30 and D35 for a pretty good price. I'm calling around soon to get quotes and see what getting them installed looks like, otherwise I'll do it myself.

[QUOTE=rckymtnt4r;343852]This is escalating quickly.[/QUOTE]

welcome to my world, lmao. :lmao:


My wife says the same thing as we talk about the goals for my truck and the current project


hey man, it's just money right?

[quote=TDash;343869]hey man, it's just money right?[/quote]

yeah, it is... got quoted $3000 for a regear...

[quote=rckymtnt4r;343875]yeah, it is... got quoted $3000 for a regear...[/quote]

This is why I still run 3.73 (stock) gears on mine. 4.10 or 4.56 would be nice, but the labor + lockers are not cheap.

Ah, yes. This is the thread I was looking for: [URL]https://www.jeepforum.com/forum/f9/extreme-novice-regear-thread-965764/[/URL]

Posted here for reference if anyone else is interested.

[quote=open_circuit;343876]This is why I still run 3.73 (stock) gears on mine. 4.10 or 4.56 would be nice, but the labor + lockers are not cheap.[/quote]
I'm <s>retarded</s> brave enough to try this on my own. :wrench:

i am 99% sure that whoever had my truck before me never re-geared when they threw the 37s on and there are times my 5.3L feels like a 4 banger so personally i can not wait until i get my new 5.13 gears along with my other crap

Be happy to help you with setting up new gears and installing locker....I am no expert, but have a little experience with diff work and setting pinion depth and backlash etc....it's tedious but not impossible. I'd highly recommend pulling the axles out and working with them on the bench...it may be more work pulling the axles than doing the R&P work.