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-   -   99 TJ 33's best gears? (http://www.wranglerforum.com/f282/99-tj-33s-best-gears-89057.html)

Bassett99TJ 04-12-2011 02:35 PM

99 TJ 33's best gears?
 
Have a 99 TJ with auto and 33's. What is the best gear ratio to use?

6InARowMakesItGo 04-12-2011 02:44 PM

engine?

deathphoenix99 04-12-2011 02:45 PM

4.10's or numerically higher.

JaxJaguars 04-12-2011 02:47 PM

2.5l - 4.88

4.0l - 4.56

JaxJaguars 04-12-2011 02:49 PM

Well those are for a 5 speed. Idk about the auto

fire239 04-12-2011 07:46 PM

If you drive on the highway or like to ever go over 65-70...4.10 The nice thing about the 3spd auto/4.0 of the older TJs is that you can usually just pick up stock axles with the correct gears instead of having to regear. I have that combo and drive alot of interstate...I really think I could get away with 3.73s (have 3.07s now)

68USMC72 04-12-2011 08:14 PM

98 TJ stock gear ratio
 
Does anyone know what the stock gear ratio was for a 98 TJ?

4.0 with 5 speed

Jerry Bransford 04-12-2011 08:16 PM

For 33" tires, the 4.0L engine, and the 3-speed automatic transmission, you want 4.10 gearing. If you have the 2.5L engine, bump that to 4.56. :)

Jerry Bransford 04-12-2011 08:19 PM

1 Attachment(s)
Quote:

Originally Posted by 68USMC72 (Post 1175109)
Does anyone know what the stock gear ratio was for a 98 TJ?

4.0 with 5 speed

3.07 or 3.73. Look on your axle tag to know what you have, as shown below. The one in the photo indicates the axle has 3.73 gears inside.

68USMC72 04-12-2011 08:42 PM

Thanks, Jerry . . . I'm new to this site but it seems great.

Ratdaddy 04-12-2011 10:53 PM

Nice, I was just going to ask the same.. Thanks

Bassett99TJ 04-13-2011 11:12 AM

I have the sweet 3 spd with the 4.0, looks like i will be going with the 4.10. Thank you so much for your help.

Jerry Bransford 04-13-2011 11:32 AM

Quote:

Originally Posted by Bassett99TJ (Post 1176107)
I have the sweet 3 spd with the 4.0..

I miss my 3 speed automatic, that's a great (!) transmission. :punk:

Bassett99TJ 04-14-2011 01:04 PM

Good to hear the the 3spd is a great tranny. What do you have now and why did you get rid of the 3 spd?

KebHund 03-31-2012 03:52 PM

Quote:

Originally Posted by deathphoenix99 (Post 1174410)
4.10's or numerically higher.

Hi, would you prefer 4,10 or 4,56 on 3 speed auto? I am in the same situation.

6InARowMakesItGo 03-31-2012 04:00 PM

Quote:

Originally Posted by KebHund (Post 2204243)
Hi, would you prefer 4,10 or 4,56 on 3 speed auto? I am in the same situation.

if you have a 4.0L then you want the 4.10s with the 3 speed and 33" tires.

gsueagle2424 03-31-2012 04:10 PM

So I have 3.07 right now with 31's 5sp 4.0L. I don't any problem running 75-80mph right now (I just have a small 3-4 mile stretch of interstate on my way to work). Would upgrading to 32's or 33's eventually be a bad thing?

Are there any benefits to the 3.07 gears?

Jerry Bransford 03-31-2012 07:54 PM

It'd turn into a real dog going with bigger tires with 3.07 gearing.

The only (!) benefit to 3.07 is more theoretical than practical and then this is only true with small tires... it reduces engine RPMs dramatically which in the right driving conditions and with small tires can give better mpg. But in typical (imperfect) driving conditions with larger tires, the engine rpms are so low that the engine is running inefficiently and lugs which actually harms mpg.

If you went to 33" tires, 4.56 would be a good all-around road and offroad ratio. 32" and smaller 4.10 would be a good choice.

Wesboy 03-31-2012 08:09 PM

Quote:

Originally Posted by Bassett99TJ (Post 1176107)
I have the sweet 3 spd with the 4.0, looks like i will be going with the 4.10. Thank you so much for your help.

I've just put 4.10's in my '97 3 speed auto and the RPM's on the highway are MUCH higher.
65mph=2800RPM
70mph=3000RPM
75mph=3250RPM

On the plus side,
Off the line is much faster - should be handy for drag racing :nonono:

There is no more constant downshifting on steep hills and headwinds.

Offroad is amazing. I can now do steep tricky descents without being on the brakes constantly.
It's great to be able crawl in low range again, without the Jeep wanting to run away from you.

When I had the old ratios (3.07's) often had to have the pedal to the metal just to maintain speed if I was on the highway and punching a headwind or going uphill.
Now I'm using a lot less accelerator but as stated above, RPM's are much higher (on the highway).

SpoiledRotten 02-18-2013 08:25 PM

I'm reviving this older thread to ask a question along the same lines. I'm fixing to regear. I have a 2000 TJ with the 4.0 and 5 speed. I want an all around gear for mostly road but want to be able to handle about any terrain when off road. What do I need?

Jerry Bransford 02-18-2013 08:28 PM

Quote:

Originally Posted by SpoiledRotten (Post 3387356)
I'm reviving this older thread to ask a question along the same lines. I'm fixing to regear. I have a 2000 TJ with the 4.0 and 5 speed. I want an all around gear for mostly road but want to be able to handle about any terrain when off road. What do I need?

There is a crucial piece of missing information... your tire size. :)

SpoiledRotten 02-18-2013 08:31 PM

Quote:

Originally Posted by Jerry Bransford (Post 3387383)
There is a crucial piece of missing information... your tire size. :)

Ah yes, Jerry. I did forget that... I have 33's. I might go to 35's when these wear out, but I do like the 33s.

BTW, I hope you're still enjoying that newer Jeep after yours was stolen. Hated that happened but glad it turned out ok for you.

1jeeplvr 02-18-2013 08:33 PM

Quote:

Originally Posted by Wesboy (Post 2204813)
I've just put 4.10's in my '97 3 speed auto and the RPM's on the highway are MUCH higher.
65mph=2800RPM
70mph=3000RPM
75mph=3250RPM

On the plus side,
Off the line is much faster - should be handy for drag racing :nonono:

There is no more constant downshifting on steep hills and headwinds.

Offroad is amazing. I can now do steep tricky descents without being on the brakes constantly.
It's great to be able crawl in low range again, without the Jeep wanting to run away from you.

When I had the old ratios (3.07's) often had to have the pedal to the metal just to maintain speed if I was on the highway and punching a headwind or going uphill.
Now I'm using a lot less accelerator but as stated above, RPM's are much higher (on the highway).

Just had my 4.56 gears installed on my 4.0,5sp & havent wheeled it YET but on road is night and day.I never thought I would be able to accelerate up a hill in 5th gear

SpoiledRotten 02-18-2013 08:40 PM

I think I had 4.56 and 4.88 mixed up. I surely wouldn't want to do 4.88 unless it was a dedicated offroad vehicle, right? Either 4.10 or 4.56? I wouldn't mind having enough gear for 35s if I went that way later.

Greengoblin98 02-18-2013 08:42 PM

I'm in the same boat but I'm actually wondering what my ratio is. I thought I had 3.73 but people with that have lower rpms than I do at 65 mph. Somebody with 3.73 with 32x11.5r15 at 65 mph is around 2400 rpm. With that same combo, I'm around 2800 to 2900 rpms. Was wondering what ratio y'all thought I had.

Jerry Bransford 02-18-2013 08:42 PM

4.56 is the ideal street/trail ratio for 33" tires, 4.0L engine, and 5-speed manual transmission.

Jerry Bransford 02-18-2013 08:43 PM

Quote:

Originally Posted by Greengoblin98 (Post 3387502)
I'm in the same boat but I'm actually wondering what my ratio is. I thought I had 3.73 but people with that have lower rpms than I do at 65 mph. Somebody with 3.73 with 32x11.5r15 at 65 mph is around 2400 rpm. With that same combo, I'm around 2800 to 2900 rpms. Wa wonderibg what ration I had.

What size tires are you running, what transmission do you have, what model year is your TJ, and have you recalibrated your speedometer so it is accurate with the size tire you are running?

Greengoblin98 02-18-2013 08:44 PM

I also have 4.0 3 speed auto.

Greengoblin98 02-18-2013 08:45 PM

Quote:

Originally Posted by Jerry Bransford
What size tires are you running, what transmission do you have, what model year is your TJ, and have you recalibrated your speedometer so it is accurate with the size tire you are running?

32x11.50r15, 3 speed auto, 98 Sahara, and I have no clue. Bought with lift and everything already on it.

Jerry Bransford 02-18-2013 08:51 PM

With a properly calibrated speedometer, your engine should be turning over 2550 RPMs at 65 mph with 32" tires, 3-speed automatic, and 3.73 axle gearing.

Engine RPMs with a properly calibrated speedometer would be 2800 at 65 mph if you have 4.10 gears in the axle.

The operative words being 'calibrated speedometer'. Use a GPS to compare what it says compared to what your speedometer says.


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