Our third and final post in our series tackling Tacoma driveline vibration solutions deals exclusively with carrier bearing drop kits. These kits are not intended to help Toyota Tacoma drivers who own stock ride height vehicles, but rather address the driveline vibration concerns of those running a fairly aggressive lift kit.
What Is A Carrier Bearing Drop Kit?
A carrier bearing drop kit is designed to lower the bearing that holds the two-piece driveshaft in the Tacoma in place at the joint. Lifting the Toyota Tacoma changes the pinion angle between the driveshaft and the truck’s rear end, which can create vibration and other oscillating movements in the carrier bearing’s rubber. In order to correct this angle and bring it back as close to stock as possible, a drop kit lowers the bearing by using spacers to put distance between it and the cross-member it is fixed to.
When Is A Carrier Bearing Drop Kit Useful?
I once again turned to Kevin Kelly at KLM Performance to answer my questions about carrier bearing drop kits. He told me that in order for a Tacoma owner to see any vibration reduction benefits from this type of aftermarket solution they would have to be running a lift of at least four to six inches. Anything less than that and the level of driveline angle change is not significant enough to be positively impacted by lowering the carrier bearing.
Kevin also said that a carrier bearing drop kit – like rear axle shims – should be used as part of an approach to eliminating vibrations that takes into account all aspects of the vehicle’s driveline. This means that it’s not enough to simply install a kit like this and hope for the best. A full analysis of any driveline angle changes introduced by a lift kit must be performed, and a combination of different solutions to achieve a stock-like drivetrain geometry is often the best method of ensuring a smoother ride.
Tundra Driveline Geometry – A Systematic Solution
After speaking with both Kevin and Troy about the three different driveline vibration solutions profiled in our series, it has become clear that there are no easy answers to this problem. With so many potential causes for the shuddering and harshness experienced by lifted – and on some occasions, stock – Tacoma owners, the best advice seems to indicate that drivers should avoid the temptation to “solve” the problem with an aftermarket component and instead purchase only those parts which can work together to improve the truck’s overall driveline geometry.
It’s not a simple task, but it’s much more cost effective than throwing a bunch of parts at the problem and hoping for the best. Each of the components discussed in these three articles:
- After-market Tacoma drive shafts
- Tacoma rear axle shims
- Tacoma carrier bearing drop kits (this article)
offer a potential path towards a shudder-free ride – but only if they are used effectively and in concert with a Tacoma’s particular suspension design.