Tundra Magnuson/TRD Supercharger Pulley Instructions
These instructions assume the person doing the removal and installation have good mechanical aptitude. If you are uncomfortable with what this entails, take your truck or supercharger to a professional shop. Sniv Speed Shop is not liable for any damage you cause to your truck or supercharger due to incorrect installation or removal. If you know how to remove and install a pulley, most of this can be skipped to the last section “Pulley Installation to Hub”.
There are multiple ways to remove your current pulley, and install the Sniv Speed Shop modular pulley. This will document some of the methods, and my personal preference. Your skills, tools available, and willingness to wrestle the supercharger, will all affect what path you choose.
- Supercharger Nose Removal
Removal of the supercharger, and in general the supercharger nose, helps everything. Personally I start by unbolting the supercharger and angling the nose up so you can access all the supercharger nose bolts, undo those and pull the snout and it will slide forward and off of the supercharger. There are 6x bolts, 5x on the bottom and 1x near the top, all facing forwards. Superchargers Online has a good write up if you search “Tundra Magnuson Supercharger Coupler Replacement”. By removing the nose you can easily maneuver around to remove the pulley, and can use a press for simple installation of the new pulley. Even if you don’t remove the nose, having the supercharger loosened or removed makes fitting tools around the pulley much easier. You can access the nose bolts without removing the supercharger, but the coolant crossover is in the way making it not feasible to slide the nose forward and off. The cooling system does NOT need to be touched to loosen the supercharger and pull the nose off.
- Pulley Removal
A tool is required to remove the pulley. Usually this will require removing the supercharger or nose (part the supercharger pulley shaft inserts into). There is a tool from “qualitysuperchargers” on ebay that appears to not need removal of the supercharger, though I’ve never used it. My preference is the large 3-jaw puller you can rent at an auto parts store, though I’ve made do with smaller pullers. If your supercharger shaft is threaded and you want to use those threads for installation (reference “Pulley Installation” section) then you should thread a bolt into the threads (socket head cap screw would seem best) to keep the threads intact. If you use a 3-jaw puller it will look something like this (credit to M3Tundra from Tundras.com forum):
And here is using a smaller 3-jaw puller I had laying around with some modification to keep the arms from separating:
The key to removing the pulley is to make sure the arms do not slide off! Otherwise it comes off fairly easily.
- Pulley Hub Installation
Do NOT lubricate the shaft or pulley hub! The pulley hub relies on friction from the press fit to keep it from spinning on the shaft, a lubricated shaft will make it easier for the pulley hub to slip!
There are multiple ways to install the pulley. URD sells a “tool” which is a M8x1.25 threaded bolt and you simply thread the bolt on and suck the pulley down. Not all Magnuson shafts are threaded, but if yours is and you decide to do this use lots of anti seize on the bolt. Personally I am not a fan of this method, to me it always feels like the bolt is going to strip, but it can be done without removing the supercharger and doesn’t require machinery. Reference URDs website for more details if you need ideas.
Personally I like to use a press, doesn’t have to be anything fancy, a Harbor Freight one will work great if you or a friend has one. With the nose removed, set the pulley on the shaft, and put a socket between the bottom of the shaft and the plate (there are three prongs that interface the coupler inside the supercharger, we don’t want to bend those so we push directly on the shaft using the socket as a spacer). And then press away and it’s easy!
The pulley hub should be installed so the front face is flush with the end of the supercharger shaft. This should place the back of the hub so it barely clears or is just “kissing” the bearing that is pressed into the nose housing.
- Pulley Installation to Hub
I recommend applying the included anti seize to the included bolts (only 12x bolts are required, with spares included) AND to the forward face of the hub that has the tapped holes. Due to the hub being stainless steel and the pulley being aluminum, galvanic corrosion can occur (this is what may cause your wheels to stick to the hubs). To help alleviate any future sticking, all contact surfaces and bolts are recommended to have anti seize applied.
The aluminum pulley is designed so it can be mounted in any orientation. Due to tolerancing during machining, there may be a preferred orientation of the pulley that is easier to slide on and off. The front of the hub has a slight chamfer, this is to help with installation of the pulley when a belt is wrapped onto the pulley. Due to how tight the Tundras serpentine belt can be, it may be easiest to have the belt wrapped around all the pulleys (including the supercharger pulley, but not yet installed) and then slide the supercharger pulley straight onto the hub. Because this does not require brute forcing the pulley over the edge of a belt, it may be an easier installation option due to the pulley sliding straight back.
Ensure the pulleys shear tabs are aligned and the pulley is fully seated back. The shear tabs should sit close to flush with the inner face of the pulley. The 12x bolts may then be installed (remember to add anti seize to them). The bolts are 4-40s and use a 3/32 allen key (included). There is no torque spec for the bolts because they are extremely small and in the order of inch-pounds of torque, so my recommendation is to gently snug all the bolts (using the long side of the wrench do a light ~1/8 turn or less). The bolts are multi-redundant and are not part of the load path, the hub and shear tabs are designed to react all the load. Because of this, the bolts can be lightly torqued and checked every few thousand miles. In the event a bolt breaks during installation, or falls out, or is lost, the pulley is fine to operate. The pulley should be fine to operate with as few as 4x bolts in a square pattern. Point being, be gentle with the bolts, but if something happens do not worry, there are lots of bolts for redundancy, not because they are required.
Once installed, the pulley should have a small gap between the supercharger nose housing and the pulleys outer flange:
Pulley Hot Swapping
I keep my pulleys in the glovebox, along with an Allen Key. If you have a breaker bar and socket, you can easily swap pulleys in roughly 15 minutes. Use the breaker bar to release the belt tensioner by resting the breaker bar on the sway bar. Use the Allen Key to undo the 12x bolts, slide the pulley forward and off the hub with the belt still attached. Remove the pulley, place the new pulley underneath the belt and engage the belt and pulley, slide the pulley with the belt wrapped around it onto the pulley hub and visually align the shear tabs. Press the pulley on, install the 12x fasteners and lightly tighten by hand. Remove the breaker bar from resting against the sway bar. Voila, you just adjusted your truck from mild to wild or went from a high boost for high elevation setup to a milder setup for your trip to the ocean.
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