Torsion Bar Adjustment

Oct. 01, 2005 By Chris Geiger
How To Adjust Torsion Bars on IFS Toyota Trucks
Author: Chris Geiger -

You can adjust the height of the front suspension by adjusting the torsion bars on IFS Toyota trucks (except Tacoma) '86-'95. These springs, as with all springs "sag" with time and use. Off-road driving accelerates this sag. Front torsion bars can be easily adjusted and the front suspension can be returned to the factory height or even lifted about 1.5"- by just turning a bolt! 

If you drive off-road more than the average driver than you may want to consider using heavy duty torsion bars. These bars won't bend as easily and don't require readjusting after harsh driving. Heavy duty bars also give a slightly stiffer ride and prevent bottoming out of the suspension. The stock torsion bar is 22.8mm, heavy duty bars are available in 24mm and 26mm sizes. The 26mm size is the most common and is available from many offroad parts companies.


Jack up the front of the truck at the front IFS cross member to get the wheels off the ground and to let the strain off the torsion bars. This must be done or you will destroy the adjuster bolts. Don't forget safety, put a pair of jackstands under the truck before you start working under it.

The torsion bar adjuster bolts are located under the truck near the frame rails about 10" back from the transfer-case cross member. Spray the bolt threads with WD-40 or similar. 

If you have a '86-'88 you may have a lock nut that must be removed before adjusting your bars. If your truck has this lock nut it may be difficult to remove. You may need to add a pipe on the end of your wrench to get this nut loose. This design was changed sometime in 1988 to the type shown below.

This is a picture of the adjuster bolt and nut from truck in the '88 - '95 range. If you have this type, there is no locknut to remove. 

Now Tighten the 22mm bolt head a few turns (5 to 10 revolutions). Look at the upper nut when doing this, it should not turn, the bolt should turn inside without turning the nut. If the main nut turns with the adjusting bolt then you may already have a bad bolt bad in need of replacement. You should replace the nut and bolt as a set for about $6 at any Toyota dealer. 

You can put a wrench on the main nut while turning the bolt head but if it is hard to turn the bolt head it's time to replace the main nut and bolt. Do the same adjustment to the other side of the truck. Turning the bolt the same number of times. Here you can click to see what a new set of bolts looks like. 

Old style ('86-'88)                   New style ('88-'95)

Here are the Toyota Part numbers incase your threads are stripped and you will need to buy new bolts/nuts:
Bolt Nut Lock-Nut
86-88 90101-12104 90170-12025 90170-12004
88-95 90101-12159 90179-12074

Drive down the street to set the bars in place. Measure the distance between the fender and the top of the rim on both sides (on level ground) and make adjustments on one side or the other until they are the same height. 

You should consider replacing the extension bump stops (the upper ones) to prevent the suspension from "topping out" and giving a harsh ride. There are 2 sizes available, low and ultra low. Replacing the upper bump stops (total of 2, 1 on the right and 1 on the left) will increase the travel available by allowing the tire to travel down farther than with the stock bump stops. Replacing the lower bump stops (total of 4, 2 on the right and 2 on the left) with low profile stops will increase the travel available by allowing the tire to travel up higher than before, however this may cause a bit of tire rubbing with larger than stock tire & wheel sizes. 


You can only adjust the torsion bars up to a point, beyond that, problems will be encountered including: harsh ride, increased axle shaft and axle boot wear. Most trucks and 4Runners are set at the factory to about 13.5" - 14" from the top of the rim to the fender lip. You can adjust the bars up to a measurement of 15" (not including any installed lift) with only a slight loss of ride comfort.

With the use of low or (ultra low) profile bump stops available from Energy Suspension you can regain some ride comfort by allowing the upper arms to drop a little further. The higher you lift by adjusting the bars the greater the angle in the CV and tulip joints on the front axle shafts especially on trucks equipped with ADD. Trucks that came from the factory with manual hubs can reduce wear to the front drive shaft by unlocking the hubs when not using 4WD.


You can lift the rear of your truck with extended shackles, longer springs, blocks, or add-a-leafs if you have a leaf spring suspension. For 4Runners with coil rear suspension You can replace the rear springs with units that are about 1.5" - 2" longer and make a perfect compliment to heavy duty torsions bars. After adjusting the torsion bars you may be able to use 32 X 11.50 tires on stock 7" wheels with little or no rubbing. (assuming you have removed running boards, front mud flaps, and flattened the fender seam flat with a hammer) 


Trucks with the ADD system (Toyota's Automatic Differential Disconnect System) have axle shafts that turn whenever the truck is in motion, even in 2WD, unless manual hubs have been installed. This unnecessary shaft turning can cause premature wear of the drive shaft boots especially in trucks at or near the 15" fender to rim limit. If your truck is equipped with ADD and does not have manual hubs, I recommend that you set your torsion bars to a maximum of 14" fender to rim. For instructions on how to disconnect the ADD system See the ADD page. Newsletter
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