Jeep TJ to Durango Steering Gear Swap

 

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As there seems to be a lot of Jeep owners out there considering this swap and because we have done the swap ourselves we decided to provide our readers with an article on the subject.

In this article we are not going to provide you with step by step instructions on how to swap your TJ steering gear with a Durango steering gear. There are far to many sites out there (and manuals for that matter) that provide this information.

What we do hope to do is to clear up the confusion behind this conversion and to answer the questions that we see all over the net on forum groups pertaining to this swap.

From what we have seen on the forums here are some of the most common questions and misconceptions surrounding the Durango Steering Gear.

1. "The Durango steering gear is more heavy duty than the TJ" This is a hard statement to quantify. It depends on what you consider to be "heavy duty".  The fact is that the Durango gear has the same casting thickness to the housing as the TJ, however the actual size of the piston and bore are a bigger diameter than the TJ. Therefore the Durango gear is better suited for turning larger tires and is the entire reason for changing over to it if you are running larger tires on your Jeep.

2. "The Durango gear has a tighter turning radius" Absolutely not!  It's funny to read the forums and see what some people write. Turning radius is determined by where your steering stops are set at the axle not the steering gear.

3. "The Durango gear with the 3 3/8 "stop to stop" is faster than the one with 2 15/16 turns because it is a higher ratio" This is a very common misconception as a lot of guys think of this number as a "Ratio" IT IS NOT A RATIO, it is an actual measurement of number of turns from stop to stop and refers to how many full turns of the steering wheel it takes to go from one steering stop (full left for example) to the other (full right). The lesser the turns of the wheel the "faster" the steering is said to be. Therefore if you have a gear that takes 4 turns from stop to stop it would take 4 full revolutions of the wheel to go from full turn in one direction to the other.   The stock TJs gear is 3 3/8 turns lock to lock. The Non-Snow package gear on the Durango is 2 15/16" which is a bit faster but isn't really that big a difference as to be noticeable in everyday driving.

4. "The Durango gear with the snow plow option is heavier duty" The difference between the two options as it was explained to us by our local steering gear re builder is that the gear with the snow plow option had extra ports for the plow lines and also have the larger stop to stop number (see specs below). Therefore the "NON-plow" gear is the one that you want for the TJ swap. There is no difference in the housing thickness or piston/bore diameter.

The questions we see asked most often are these:

1. "Which year Durango gear do I use?" The answer here is '98 or '99 Durangos, non-plow option. I have not seen a difference in part numbers due to the engine installed but if you are asked, specify the 318 engine.  We prefer the non-snow option gear due to the above listed quicker steering response.

2. "What year of TJs does this swap work on?" 1997-2002 model year TJs. The hose size, bolt patterns and steering shaft input are identical for these years TJ boxes to the '98 and '99 Durangos. 2003 and later model year TJs had a Mercedes gearbox with different bolt patterns and hose sizes so the swap won't work for them.

3. "Will replacing the steering gear fix the loose steering on my lifted TJ?" The answer here really is no. Several things can contribute to loose steering which can include but are not limited to: Loose tie rod ends, worn steering column shaft or joints, loose or broken pitman arm, ball joints and caster angle. Also, DO NOT think that replacing the steering stabilizer will fix loose steering problems. Replacing the gear will rarely fix loose steering either. Usually the gear is replaced when an over abundance of oil is seen leaking from it's seals. Most owners will report that changing from the stock TJ gear to the Durango gear did nothing to fix a loose steering condition.

4. "Can the gear be adjusted to solve loose steering?" Yes and No, there is an adjustment for the gear lash on top of the saginaw gear boxes however they are usually adjusted correctly from the factory or rebuild shop. Improper adjustment of the nut on top of the gear can lead to binding of the gears and destruction of the gear, therefore it is advised that if you don't know what you are doing you leave it to a good mechanic that does. Also from what we have seen, adjusting the gear rarely completely solves loose steering problems.

A few things to consider about doing the Durango gear swap:

If you have a stock TJ there is no real reason to do this swap.

The major reason for the Durango swap is due to the increased turning power provided by the larger internal piston which is better suited for Jeeps with larger than stock tires (34" or larger)

A word on core returns:

The pimple faced kid at the local Shucks/Checker or Autozone parts store probably knows much less about actual auto parts than he does about loud chrome mufflers for Hondas so you may slide your TJ gear past them as a core return for the Durango gear.   However, most knowledgeable mechanics and re builders will check part numbers and can tell the difference. Ask if you can return a stock TJ gear in exchange for the Durango gear BEFORE you buy just in case, otherwise you could be out a lot of money. One reputable re builder here in the Seattle area was willing to take our old TJ gear in exchange but stated that it wasn't something he would do on a regular basis. We sweetened the pot a bit with an additional TJ gear which was worn out and on it's way to the dump anyway.

The Specifics:

Swap only good on '97 - '02 model TJs
Durango gear needed: '98 or '99, V8 engine. We prefer the NON-Snow gear for it's slightly faster turning.

Number of Mounting Holes: 3
Number of Turns Lock to Lock: 3 3/8
Input Shaft Diameter: 3/4"
Line Thread Size: M18x1.5; M16x1.5
Output Shaft Diameter: 1.25"
NAPA Part#: NSP277582

Number of Mounting Holes: 3
Number of Turns Lock to Lock: 2 15/16
Input Shaft Diameter: 3/4"
Line Thread Size: M18x1.5; M16x1.5
Output Shaft Diameter: 1.25"
Type of Hose Ports: O Ring
Napa Part#: NSP277588

Number of Mounting Holes: 3
Number of Turns Lock to Lock: 3 3/8
Input Shaft Diameter: 3/4"
Line Thread Size: M18x1.5; M16x1.5
Output Shaft Diameter: 1.25"
Type of Hose Ports: O Ring
NAPA Part#: NSP277580