Heaviest load and/or largest trailer towed with Jeep?
01-18-2010, 07:41 AM
#11
JK Jedi Master
Thanks for all of the replies! Regarding the quote above - I did not know that. Of course one thinks they look into everything and there is always something they miss but this is a big one for me. 
The next questions that come to mind from changing the gearing from 3.21 to 3.73:
1) cost?
2) Pros - cons when NOT towing? Why not ship all 4dr Saharas with 3.73 gearing?
I'll do some research but if anyone has insight into this please let me know.
Thanks! Keith
The next questions that come to mind from changing the gearing from 3.21 to 3.73:1) cost?
2) Pros - cons when NOT towing? Why not ship all 4dr Saharas with 3.73 gearing?
I'll do some research but if anyone has insight into this please let me know.
Thanks! Keith
The mpg difference between the two, (3.73 and 4.10) will be negligible.
Performance will be way better than 3.21.
4.10 will leave room for a little bigger tire, should you want them later.
I have 4.10, and get 18 around town, and 22+ on the highway, with an automatic. I didn't see you post what transmission you have.
Last edited by ronjenx; 01-18-2010 at 07:43 AM.
01-18-2010, 07:51 AM
#12
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I have an automatic. The towing section in the manual only lists a 3.73 gear available with the 4x4 4dr Automatic Sahara. Could it be that the window sticker (used car) was wrong when it listed 3.21 gearing? How can I tell what gearing this machine had stock?
If I have 3.73 gearing I will stay as is. However, if I have 3.21 gearing then I will consider it.
Do you know what regearing costs, either to 3.73 or 4.10?
If I have 3.73 gearing I will stay as is. However, if I have 3.21 gearing then I will consider it.
Do you know what regearing costs, either to 3.73 or 4.10?
01-18-2010, 07:56 AM
#13
JK Jedi Master
I have an automatic. The towing section in the manual only lists a 3.73 gear available with the 4x4 4dr Automatic Sahara. Could it be that the window sticker (used car) was wrong when it listed 3.21 gearing? How can I tell what gearing this machine had stock?
If I have 3.73 gearing I will stay as is. However, if I have 3.21 gearing then I will consider it.
Do you know what regearing costs, either to 3.73 or 4.10?
If I have 3.73 gearing I will stay as is. However, if I have 3.21 gearing then I will consider it.
Do you know what regearing costs, either to 3.73 or 4.10?
If you want to know for sure, and remove all doubt, do this:
Chock the front tires, fore and aft.
Put the transmission in neutral.
Emergency brake off.
Jack the left rear tire off the ground.
Put a jack stand under the frame, just in case the jack fails (had to add this).
Put an index mark on the aft end of the drive shaft, visible from the left rear wheel.
Put an index mark on the left rear tire at the 6 o'clock position.
Rotate the left rear tire 2 complete revolutions while counting how many times the index mark on the drive shaft passes its original position.
That number will be your axle ratio.
Remove jackstand and lower jack.
Put transmission in gear or Park, apply emergency brake.
Remove chocks.
If you have limited slip, jack up both rear wheels and rotate one revolution, making sure both tires rotate equally.
If the driveshaft rotated almost 3 1/4 turns, you have 3.21
If the driveshaft rotated almost 3 3/4 turns, you have 3.73
If the driveshaft rotated a little over 4 turns, you have 4.10
01-18-2010, 08:48 AM
#14
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Thanks for your detailed directions! I called the dealer before I read your reply and they looked up my build and said it was ordered with a 3.73 gear. The new sahara 4drs 4x4s only allow a 3.73 gear with an automatic so I guess (hope) the dealer is correct. Maybe when I have my rig up on a jack I'll do what you suggested just to confirm.
