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USBrit 06-05-2008 09:06 PM

Transfer case speedo gear change
Here is some advice about this apparently simple mod to your Jeep.
I have 33's with 4.56 which technically requires a 39 tooth gear. This gear is hard to get hold of so I fitted a 38 tooth which is very close and has my speedo read approximately 1mph more than I am going which is cool. Also I plant to go to 35's at some point which requires a 37 tooth gear and my speedo then will read about the same less than I am traveling.

When you buy the gear most sites reccomend you buy the 'O' ring also; I thought that since my Jeep was only a couple of years old that the seal would be ok. I changed the gear in a hurry and did not check the ring which was a mistake. There are two things you need to make sure of: 1. that the tooth number range moulded into the housing that matches the new gear is positioned next to the marker dimple on the T-case. 2. Your 'O' ring is seated properly and is in good nick.
I found my T-Case leaking today; I took out the gear housing and found that the 'O' ring was split in two I am not sure how it happened but I wish now that I had taken my time putting the new gear in which takes only a few minutes taking it easy.

Triple88a 06-06-2008 10:03 PM

thanks for the head up man, i'll be doing this soon.

4Jeepn 06-07-2008 12:01 PM

You can also get the the new gear at the dealer, if your having problems find the correct one, mine was about 12 bucks as I recall. Don't recall an O ring, but good info to have.

Neil F. 06-10-2008 09:53 AM

The o ring is available from the deaer for $3 or you can match it up at the hardware store for $1-2. Tip LUBE UP THE O RING AND OPENING REAL WELL. It's easy to pinch and tear it going back in.

Triple88a 06-10-2008 04:42 PM


Originally Posted by Neil F. (Post 236366)
Tip LUBE UP THE O RING AND OPENING REAL WELL. It's easy to pinch and tear it going back in.

:rolleyes::banghead: :flipoff::wavey:

USBrit 06-10-2008 07:32 PM

Yes I had heard it would be cheaper to get the gear from a dealership; however my local Jeep dealer is a rip off merchant and not to be trusted in my view. I would rather pay extra to Quadratec then give them my dollars. Oiling up the ring before you put the housing back is good advice that I forgot to include; the same principal as smearing oil on the rubber gasket of a new oil filter.

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