Here is information useful in order to help maintain your Timbren suspension, and to align it to the factory specifications.
As outlined in the Timbren manual, the Timbren suspension system periodically requires maintenance. Within the first week of use, torque of all bolts must be checked. Subsequent to this, after 4 months, the same check, and then yearly. It's recommended that these fasteners be checked after EVERY off road excursion where severe loading is encountered. See below for a table copied directly from the Timbren manual:
The control arm outboard bolts are highlighted in blue, above. The torque specification for these bolts is 155-165 ft-lbs (210-224 Nm)
There are 6 bolts in total retaining the Timbren suspension mount to the trailer frame. Each of these should be checked for torque to 165-175 ft-lbs (224-237 Nm.)
The above item 8, the axle nut, can be used to take slack out of the hub bearing assembly. Just the same as with the mounting bolts, the torque of this bolt should be checked if there is any lateral movement in the wheel assembly when the tire/wheel is raised from the ground. Free spinning of the assembly must also be confirmed.
Finally, the main pivot bolt for each suspension, highlighted in blue below, should be checked for torque at 430-470 ft-lbs (583-638 Nm.) This is best performed at a service shop that has a torque multiplier or a controlled torque wrench - truck and trailer service facilities.
With the basics out of the way and knowing good information about bolt locations and torques, we can go on to the information on alignment. The specification for alignment is that toe in is set between 0" and 1/16", and that camber is set to 0 degrees, plus or minus one half of one degree. See below for another reference from the Timbren manual. Take particular notice that the two measurements are taken at a diametrical distance of 30 inches. On each side, it is helpful to use a piece of angle or other scrap material, cut to length and drilled such that it can be installed on a pair of the lug studs.
Camber is slightly more difficult to address.
The familiar image above includes placement for an alignment shim where the shim would add negative camber to the suspension system. A 5/8" ID Grade 8 washer can also be used in this location (check your bolts first to ensure they are equal to or less than 5/8" OD, adjust fastener choice to suit.) In extreme circumstances where more than a few shims or the washers do not get the system to the correct alignment - in most cases due to excessive negative camber, there are shims available from OGT that can help. They are installed in the following two locations:
It is important when using these shims that the suspension arm mounting is not overstressed or deformed and the mounting bolts are snugged up evenly. The vertical shim is light blue in the section view below. There may be a need to install a thin shim in the area highlighted in red. This shim material should cover the entire area of the suspension mounting pad in the horizontal plane, stopping short of the vertical bolt line.
When alternate shims are installed in the horizontal plane that push camber positive, ensure that the vertical plate of the Timbren mount is not bending excessively or binding in the position highlighted below. Since the mounting surface is much shorter, shims may not be required in the vertical plane.
This document is a guideline and is meant to be used in concert with the Timbren instructions.
Timbren 3500HD Instructions at Timbren.com
If you have any questions about the alignment process, please contact OGT warranty at warranty@offgridtrailers.com or call the switchboard at (800) 786-3221 and ask to speak with technical support.
**IF you need parts, if any piece of the Timbren suspension has failed such as bushings/hubs/bearings during the warranty period, Timbren administers their own warranty of 3 years on these components. You can contact Timbren at:
or call 1-800-263-3113.
Thanks for reading, and be safe out there!
The OGT Warranty Team