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HDHD 04-07-2012 11:57 AM

gears & catalytic converter? It bogs down when shifted in to 5th.
I have a 1998 4.0L Wrangler that was bought a few years ago. We put a Rough Country 3.25 suspension lift and I'm running 33's. My problem is that since we raised the jeep I no longer can get into 5th gear. When I try shifting to 5th it bogs down. I was told that I need new gears / different size. My question is what size gears do I need? I also want to replace all of the gaskets and what not while replacing the gears. Is there a kit that has everything I need in it? I was also told to get USA Yukon brand gears. My husband and I did the lift and a few other things, but I don't think that we can do the gears our self. I want to find out what items I need so I can either order them and take it to have them installed or at least know what I need so I can look it up and know what kind of price I'm looking at. About how much does it cost for new gears installed. Also... Every so often I get a loud clanking noise, maybe my catalytic converter? Are there any tricks to fixing that, or do I need a new one?

TnDz TJ 04-07-2012 12:38 PM

Welcome to the Wrangler Forum!

First off... you need to know what axles you have and what gears are in them now. Most likely and rear Dana 35 and front Dana 30.

Depending on what gears are in the rear ( assuming its a 35 ) you may need to change the carrier that the gears ride on. If you have 3.73's or numerically higher, you won't need to.... If you have 3.07's ( highly likely) you will need to change the carrier.

OK.... so let's assume you have the above mentioned axles with 3.07's.

The BEST gear selection for the 4.0 with a 5 speed running 33" tires is 4.56 gears. This what I run in my 2004 4.0 5 speed. At 70mph in 5th I turn 2600 rpms... PERFECT. I would highly suggest this gear selection AND get a 39 tooth speedometer gear to correct your speedometer reading incorrectly after the change. Before I changed my speedo gear, 60mph on the speed was 42mph actual by I'm dead on.

You will need to change the rear carrier. Depending on what you want, this can range from $125-$900 each. From open to Limited Slip to automatic lockers to selectable lockers.. meaning you can choose to have them open or locked.

As far as rear gears....

Yukon 4.56 sets for the rear I have seen for around $250 and then you need a master install kit that consists of bearings, seals and shims. These run about $100.. give or take.

As for the front gears....

Your carrier you have now will be fine. The Yukon 4.56 gears for the Dana 30 run about $250 and the master install is about $130.

It is NOT for the average shadetree mechanic to do this install.... so plan on buying the parts needed from your professional installer to keep all the warranty and workmanship under one roof. The install can run you $200-$300 per axle.

Most shops will want to get the parts themselves ( their markup) but you are kinda stuck doing this to keep the guarantee and warranty of parts and labor with that shop... otherwise if something fails, they can blame the parts YOU bought from someone else....

So in a nutshell.... the cost you are looking at is around $1500 easy for a regear for all retail parts.... I will say that is a bit low... but gives you an idea....

So find the parts you want EXACTLY (type of carrier and gear selection).... take that list to an installer and get a quote from them for the entire package.

Jerry Bransford 04-07-2012 12:43 PM

Yep odds are very good it is bogging down simply because the ring & pinion gears in your front and rear axles are simply not the right ratio for your 33" tires.... which means the engine RPMs are not high enough as is to produce enough power to turn those heavy/larger diameter tires.

Regearing your axles will cost, on average, somewhere close to $1200 or under if you shop around and push for a discount. As suggested above, 4.56 is the ideal ratio for that size tire and your engine/transmission combination. And as suggested above, have the installing shop provide all the parts so they can't blame any parts you provided in an attempt to save a little $$$. Most shops will discount the parts anyway if you ask them to since most of their profit is from the installation labor.

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