Toyota Tundra LSD Upgrade (Kazuma TRD)

2004 Toyota Tundra Double Cab Kazuma TRD LSD Install
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This page shows what is needed to upgrade an open differential truck into a limited slip unit using the bolt in Kazuma TRD LSD manufactured by Eaton. This is not a step by step install guide. I opted to have an experienced rear end shop do the install as this is a very specialized area if any changes have to be made.

The instructions that came with the unit are quite good and very detailed. In my case, I could have done the install myself because no shimming or adjustments to backlash were required, but there is no way to know this going in. There is also a considerable amount of work involved in pulling the axles, brake lines and pinion gear and I felt it was worth it to have the shop with the right tools and a lift do this work. They kept the truck about 7 hours.

I went with this unit because:

a. manufactured to Toyota specs for TRD by Eaton
b. these aftermarket units are pre-tensioned to 400 ft-lbs as opposed to the 200ft-lb pre-tension units the factory installed
c. this is a bolt in mod requiring little labor/cost to install
d. a limited slip unit is still very street friendly yet adds substantial traction over an open differential (400 ft-lbs to the wheel with best traction)
e. the TRD design is time tested in over 6 years of Tundra's and is covered by factory warranty if installed by a dealer

	Unit comes wrapped in plastic with complete install instructions and a tube of LSD additive for whatever rear end lube you decide to use. The shop just used their stock dino GL5 90 weight and a full tube of the Equa-Torque product. So far, working well.
	Here's a close up of the first page of the instructions. The LSD is part number 00646-41301-100. Lubricant additive is 00602-41301-100. General applicability is 2000 and newer Tundra (note, fitment on 2007 and newer model unknown).
	Here's a closeup of the stamped markings. On the left, you can see this is an Eaton made unit. (Sorry that's the best photo I have.)
	Ring gear side view with TRD raised letters.
	Bolt side of unit.
	Here's all the stuff I bought in case needed by the installers. If you use your truck everyday, make sure you get what you need in advance as it takes several days for some dealers to get parts. I did NOT need the shims (small packages) but got them just in case. The diff gasket is P/N 42181-34011 for the 04 Doublecab 4x4.

So final results are:

a. LSD not even noticeable during daily driving with exception of reduced "body torque" when downshifting or upshifting
b. shims not needed. This was a direct bolt in application, but I was still glad I had an experienced rear end shop do the work to make sure the backlash was set properly and there is absolutely no whine or any noise whatsoever coming from the rear end.
c. LSD works very well. I have driven through snow covered fields in only 2 wheel drive and it is very easy to slide the rear around predictably when you get on the throttle. The unit also adds a feeling of confidence when darting into or across traffic or starting up in loose gravel or rain slicked streets. Tires do not chirp when cornering but I may experiment a little with the amount of LSD additive next time I change the rear end lube to see if I can get by with less additive.

Summary: If you've been thinking about adding an aftermarket LSD unit, this is a good way to go. Best is to order your truck with the factory LSD option and save $350 bux in labor (factory unit is only about $300 added to invoice), but by going aftermarket, you do get a unit that is pre-tensioned twice as much for better performance.

I picked up the LSD unit for around $300 delived to my door in the midwest from the west coast. The shims cost around $30 but you probably won't need them. The diff cover gasket was $8. The labor to install was just under $300.

So, for under $750 you can upgrade your truck to an LSD rear end and never look back.

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