Calgary Jeep Association

Author Topic: Gearing  (Read 1253 times)

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Offline Zooguy

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  • 83 CJ7- AMC 360
Gearing
« on: March 03, 2021, 01:10:27 PM »
I don’t know a lot about how the gearing affects the motor but I am pretty sure what gears I have is not the ideal set up. When I first heard mine had 2.73, I though it was fine since it will be mostly on paved roads for day trips. It has 35s, which look fine but I thought 33s are just as nice. Then paired to a T5 and a AMC 360. I don’t know just how bad that is and how it affects the performance. It will do a 110km but it feels off. The more I try to read about it, it seems my gears might be affecting a lot more than I know. Should I think about new gears? 3.73? 4.10?
I am pretty good with a wrench but don’t know if I should lot in getting it done in town?
Any suggestions would be great. Thanks

Offline hps4evr

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Re: Gearing
« Reply #1 on: March 03, 2021, 06:47:33 PM »
The lower the gear ratio (numerically higher) the higher the mechanical advantage your engine has turning the tires. 2.73:1 worked fine with the stock tires but with 35’s you lost that advantage. Like trying to break a 1/2” bolt loose with a 1/4” ratchet.
I don’t think the gear ratios in that T5 are that fantastic so something in the 4.10:1, 4.56:1 or 4.88:1 would work.
4.10 would be very highway friendly but not awesome offroad. 4.88 would be great offroad but would give you high RPM’s on the highway. 4.56 would be a happy medium for both.
YJ=Y’all Jealous

Offline FiEND

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Re: Gearing
« Reply #2 on: March 03, 2021, 07:00:06 PM »
there are gear ratio calculators that help with that.   depends what cruising RPM you desire.  I don't know how the 360 compares to the 4L but shouldn't be too far off each other.
4.10 gears would probably get you a strong 5th gear.  but 4.56 would be better for offroad stuff.

really up to you how it feels and how you drive it.  if it's too hard to start moving at lights or shifting like crazy on the highway or any small hills, then yea higher gearing would be a good choice.  if it's all good and you just think there's a problem, there might not be.  stop and go traffic (deerfoot) can highlight problems too.  I remember Blaire had shitty gearing and sometimes used 4low for stop n go lol.
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'97 TJ [sold]
'17 JK Rubicon

Offline Zooguy

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  • 83 CJ7- AMC 360
Re: Gearing
« Reply #3 on: March 04, 2021, 01:17:54 PM »
Thanks, that helps. I find the jeep struggles for torque but the engine bullies it into going.
Is replacing the gears a doable project or would it be smarter to have someone do it. I know it depends on skill level. I am ok but have never done gears? What would the cost be appropriately for either one. That might make the decision easier.  Thanks again for the input.

Offline hps4evr

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Re: Gearing
« Reply #4 on: March 04, 2021, 01:59:06 PM »
Thanks, that helps. I find the jeep struggles for torque but the engine bullies it into going.
Is replacing the gears a doable project or would it be smarter to have someone do it. I know it depends on skill level. I am ok but have never done gears? What would the cost be appropriately for either one. That might make the decision easier.  Thanks again for the input.
Ability is one thing but having the proper tools is another.
If you’re replacing gears it’s a good time to install limited slip or locking differentials.
Figure out which axles you have and start pricing things out. The way things are right now it may take a while to get all the parts.
YJ=Y’all Jealous

Offline renegade350

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Re: Gearing
« Reply #5 on: March 05, 2021, 08:58:16 AM »
I would suggest if you still have leaf springs is to completely get rid of the 30 + amc 20 junk and get a new set of diffs used that are already geared.  It is almost the same amount of work and likely much cheaper then gears, bearings, rebuilt kit etc.  X10 times better in the long run.  I wish I would have just done this initially when I built mine.  A passenger side drive dodge/chev 44 + ford 9 could be had for ~1000$ with the same 5 on 5.5 wheel bolt pattern. 

Offline Zooguy

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  • 83 CJ7- AMC 360
Re: Gearing
« Reply #6 on: March 05, 2021, 09:56:14 AM »
Wow, I just made a call to a local gear shop. They were great but damn that’s a big bill. I was quoted between $7500-$$8000. I’m sure that’s in the ball park but coming up with that type of cash would be tough. Maybe swapping out the axles would be better. Something to research I guess. Thanks for the suggestions so far. If anyone has a magic wand I could borrow that would be great.

Offline hps4evr

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Re: Gearing
« Reply #7 on: March 05, 2021, 01:10:35 PM »
7-8000$ just to re-gear is very very high. Typically about 7-8 hours labor for each. Gear sets typically about 250$ each. Master install kits about 150-200$ each.
Renegade350 made a good point. A Chevy/dodge front 44 and Ford 9” rear can be built for about the same price, swapped in and give you a much stronger setup.
Or even modern JK axles swapped in would be much better.
YJ=Y’all Jealous

Offline Zooguy

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Re: Gearing
« Reply #8 on: March 06, 2021, 09:27:15 AM »
I have to amend the statement about the gearing being $7500-$8000. The shop I was talking with did quote me that, but have since dropped it to around $5500-$6000. Still too much money for me but I didn’t want to leave  mis-information on the forum. I still will look into changing the gears but have to find something more affordable. Thanks for the help so far.

Offline hps4evr

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Re: Gearing
« Reply #9 on: March 06, 2021, 04:33:07 PM »
I have to amend the statement about the gearing being $7500-$8000. The shop I was talking with did quote me that, but have since dropped it to around $5500-$6000. Still too much money for me but I didn’t want to leave  mis-information on the forum. I still will look into changing the gears but have to find something more affordable. Thanks for the help so far.
If you stick with open diffs it can keep the costs down. Further down the road you can upgrade the differentials if you want or need.
YJ=Y’all Jealous

Offline Zooguy

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  • 83 CJ7- AMC 360
Re: Gearing
« Reply #10 on: March 07, 2021, 08:38:35 AM »
I might stick to open diffs if the cost is down a lot. It’s not going to see any hard off road for a long time. Right now the whole Jeep maybe has 4-5 hundred km on it. Lots of tinkering to get it right though.
So if I look for 4.10 open gears or 4.10 open axles, that seems line the right direction. I would do lockers depending on the price. But it sounds like I will outside my comfort zone price either way. Also it looks like a job that is better sourced out instead of trying to learn as I go.

Offline GoChris

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Re: Gearing
« Reply #11 on: March 07, 2021, 09:14:05 AM »
Alberta Jeep parts buy and sell group https://www.facebook.com/groups/279876149178226/
Someone is selling:
Quote
I have a set of Dana 44s out of a 2011 Jeep rubicon electric lockers front diff is trussed Yukon 4:10 gears as well as cromoly axles in the front and have a set for the rear diff complete with disk brakes and callipers direct bolt into 2007-2017
4500 obo can deliver part way as well

Might be worth thinking about, as hps4evr said, swap in some JK axles.

Offline Zooguy

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Re: Gearing
« Reply #12 on: March 07, 2021, 10:29:11 AM »
That looks like it would work. That price seems high for the year. What’s a fair price for them would you guess? Would they be a bolt on or would I need adapters and such. Sorry for all the newbie questions. Thanks for the help.

Offline hps4evr

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Re: Gearing
« Reply #13 on: March 07, 2021, 01:26:33 PM »
That looks like it would work. That price seems high for the year. What’s a fair price for them would you guess? Would they be a bolt on or would I need adapters and such. Sorry for all the newbie questions. Thanks for the help.
To fit those Jk axles in a cj would be some work for sure. All the coil mounts would need to be removed. Hopefully leaf springs perches can be used up front. Rear would be a little easier for sure. Oh and also your transfer case front output is on the passenger side not drivers side. So that’s a thing too.
YJ=Y’all Jealous

Offline Zooguy

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  • 83 CJ7- AMC 360
Re: Gearing
« Reply #14 on: March 08, 2021, 06:00:14 PM »
Well, that sounds like a lot of work. I will see what options I can come up with. Thanks for all the input so far.