While the manual alone will guide you through the building process perfectly this build guide expands on certain areas and will allow you to tap into knowledge and experiece our factory driver have gained over the years of running Schumacher sedans.

Rear Diff

The Mi3 assembly starts off with building the rear diff. As old pan car racers we really like to spend time properly assembling the diff and do a few additional steps that really enhance the smoothness and durability of the rear diff.

In addition to the tools and items called for in the assembly manual you will need:

Electric motor cleaner spray
Paper towels
600 grit wet/dry sand paper

Before starting verify that you have all the necessary parts.

Even though we are in on the development process we were very pleasantly surprised to find than the Mi3 comes standard with Ceramic diff balls!

The only factory assembled part is the thrust bearing and female outdrive. The thrust bearing is a high quality japanese tungsten carbide unit and is packed with black molybdium disulfide grease from the factory so there is no need to disassemble it.

One of the most important factors in building a good diff is keeping everything clean. Before you start wash you hands to reduce the natural oils on your fingers.

Carefully place the diff balls on a paper towel and spray some more spray onto them. Take it easy unless you want to launch the balls all over you shop.

Get some 600 grit wet/dry sand paper and spray some motor spray onto it. place a diff ring on the wet area and with a curcular motion sand the ring. If the motor spray dries out spray some more on to the ring and paper. The motor spray will clear away the steel removed by the sand paper. You want to have a consistant pattern of scoring across the full face of the diff ring. if you see any high or low spots in the area where the diff will run keep sanding. Sand both sides of both rings.

Clean the rings with motor spray to remove any residue and set them aside.

Clean the diff pulley with motor spray.

The main thing to remember is you want all the diff balls, rings and pulley to be clean and oil free.

Every racer has their own ideas about how much silicone diff grease is the correct amount to apply to the diffs. Before I say what I like to do lets cover what the diff grease does in the diff.

The diff grease is a damping fluid and lubricates the balls as they run in the diff pulley. The diff grease contributes to the limited slipped effect on a ball diff by damping (slowing down) the movements of all the components in the diff. The caused torque to contiute to be sen to a loaded wheels even if the wheel on the opposite side lifts off the ground or otherwise looses traction.

The diff grease also lubricates the ball and diff rings in order to keep them running cool and reducing wear. This is really important and is one of the reason why we use special silicone based greases on our diffs.

Silicone diff grease has a special property. It will lubricate between the ball and the pulley but offers near zero lubication between the rings and the balls. This is critical to the operation of the diff. This allows us to set the diff loose with zero slip between the rings and balls.

Over the years we have tried all kinds of diff lubes and I can say with all honesty nothing works as good as Schumacher diff grease. AE Stealth lube gets too thin and gets slung away to easily. Joel Johnson Lube is too thick when its cool but thins dramatically when it is worked hard. Schumancer Diff grease stays put and is consistant.

The Mi3 comes with a small bag of grease. Work the grease inot a corner of the bag and snip the corner so when you squeeze it you get a 1mm stream of grease. Apply a ring of grease to the diff ring and smear it flat with a clean finger tip.

Assemble the rest of the diff as directed.

Note that after setting the diff tenstion you must use a 2mm and 1.5mm wrench to tighten the locking setscrew against the end of the diff setting screw. If you don't do this the diff will come loose. If you do this right the diff will NEVER come loose. This is way better than relying locktite, a lock nut or a nylon insert.

Finally, many team drivers choose to omit the thinnest belt spacer on the rear pulley. The belt will track true without the spacer and this small change can make your drive train spin more freely.

The spool is next. There is not a lot to do here but I chose to swap the 3 screws that hold the pulley in place for alloy units from Take Off (TS301P).

I applied blue thread lock to the alloy scres and to the screws that hold the outputs to the spool center.

The yellow seal bearings on the Mi3 are really good. The come oiled not greased so they spin free from day one. I chose to spray them out with motor spray and after they dried I lubricated them with a small drop of Powers Giga Lube (PJ0005).

Whenever you oil bearing be sure to use just a small drop. You want to lubricate them not fill them. Heavily oiled bearing have a lot more drag than lightly oild bearings. Lightly oiled bearings also attract a lot less dust and dirt.

As on the rear diff I decided to omit the thinest belt spacer. This will result in less friction on the sides of the belt as it runs and a more efficient drive train.

Shocks

Shocks are one of the most important parts of a touring car. A set of consistant, well built shocks gives a racer one less thing to worry about.

Before we got into building the shock I want to give you some tips about shocks in general.

1. All shocks will degrade in performance with use. O-rings swell and get dirt embeded in them. The causes static friction (Stiction) than makes shocks resist movement.

2. All shocks lose rebound over time. All current cars use low tension orings and they can weep tiny amounts of oil over time.

3. In crashes oil can burp past the seals and you can lose all rebound instantly. This often happens to one shock and make the car feel like its tweaked even though its fine on a tweak station.

They the solution to all of this is to check them regularly for air in the shock, sticky or dirty seals, rebound etc.

There are a few trick parts that many pro drivers use to optimize their shocks.

1. Much More or Hybrid Racing soft o-rings: They are as soft as bubble gum and they swell faster than stock o-rings but they are super slick and smooth. They can make you shocks feel like you are running 5wt lighter oil in them.

2. Much More bladder rebound foams: They come in a set of diffrent volumes and densities to you can precisely tune the amount and speed of rebound you get.

The new Mi3 shocks build with no rebound at all and all our setups take this into account so build them stock at first and add rebound later if you want to try it.

The first step where is devate from the assembly manual is on the shock pistons. The pistons fit freely just between the e-clips on the shock shaft. This is fine when they are new but after a few weeks of the piston knocking back and forth between the e-clips it can wear. You will notice this when you try to quickly compress the release the suspension. You will get a odd knocking feel from the shock.

There are 2 possible solutions and both work equally well:

1. Put one .007" motor shim on top of the the lower e-clip before you put the piston on. These shims are hard to come by now so option 2 is easier.

2. Put a tiny drop of CA on a 1.5mm wrench and use it to apply the CA to the top and bottom e-clips of an assembled shock shaft.

The CA will make the fit tight but if you need ti take the assembly apart it comes apart easily. The CA will not stick to the material the piston is made from. Dont use too much CA as you do not want it to run into the piston holes.

Put 2 drops of shock oil into the bottom of the shock (the seal housing) before putting each of the parts that go into the housing (the o-ring, spacer and end cap bushing).

This is done to fill any voids so there is no air at all in the shock seal housing. You can build it like the instructions say and the shock will be good but in the first few weeks you will find that your shocks have air in them frequently. This air is from bubbles that were trapped in the seal housing and worked their way out.

Build the rest of the shocks as instructed.

When you get to filling the shocks use really take your time and make sure there are no air bubbles in them before you seal them up. You are not doing yourself an favors by hurrying here.

Our team drivers replace their o-rings before every major race they attend. Thats about 6 times a year. The o-rings (all types of o-rings and brands of cars) swell from exposure to shock oil. The can literally double in size over a couple months.

If you haven't rebuilt you shocks recently check your o-rings you will be surprised by what you find.

Thats about it for the shocks....

I have to say one thing though. The Schumacher Race Shocks are the finest dampers on earth. The are better than Tamiya TRF and Xray shocks.

Nothing comes close to being as smooth or lasting as long as Schumacher Race Shocks.

We use a special Nickel teflon coating on our shock bodies that pretty much makes them impervious to wear. That means you will never wear through the coating and end up with grey metal flake shock oil.

The shock shafts are Ti-Nitride coated spring steel.

The pistons and shock bushings are machined aceytal engineering plastic so they all fit perfectly.

Even the bleed ports on the shock caps are specifically placed to line up with where the bladder and shock body line up.

These are the best shocks in the world

After assembling the shock and making sure there is no air under the piston fill the shock until the oil it level with the top of the shock body. Place the kit bladder on the shock body and push it down. It will displace some oil. Carefull put the cap over the bladder and shock body and tighten it down. The shock will self bleed through the new side hoen on the cap and you are all set.

Kit standard the shock will have no rebound. If you want rebound place an o ring or two between the bladder and the cap or one of the foam dots from Much More or Tamiya. Right now we are running the car with no rebound and its working well but as with any new car there is still a lot of testing to do.

Prepping the chassis is next. I run on road so I never have to get too crazy rounding edges. All I do is knock off every sharp edge on the chassis and CA the edges of the chassis and big openings. On asphalt we CA the chassis to prevent delamination if you hit a corner dot or some other object with the chassis.

The cell slots are the perfect size on the Mi3. DO NOT bevel the cell slots or you cell will poke out the bottom of the chassis. Just knock off all the sharp edges so the cell shrink is not cut.

Spend a little time on the tape slot to make sure the are smooth

The bulkheads go on to the chassis with 8 screws.

The lay shaft assembly is next. there are a few critical things to look out for.

1. Do not over tighten the screws that hold the spur gear on. Just get them snug. If you crank them down they will deform the spur gear and it will look like a potato ship...not good.

2. I use a counter sunk washer and screw to secure the end of the lay shaft. The stock button head and washer will work perfectly but my way looks cooler.

3. The layshaft assembly has a little side to side play. I used one 0.1mm shim out of a Take Off 5mm shim kit (TT302) to tighten it up a little. I still have play but it is a bit less. Note that you must have some play. If you shim out all the play its less efficient and if you pick up carpet fuzz or some dirt it can cause binding.

When installing the spool and diffs we find running just one shim is all that is necessary. We run the shim on the left side on the rear diff and on the right side on the front spool.

Take you time on the suspension. We intentionally mold the arms so they are a little tight on the pins. For novices that rarely replace parts this makes the parts last longer and makes the car feel solid.

Higher level drivers can take a few minutes to fit the parts so they are free and have no play. I have a 1/8" reamer for the hinge pins. Just a turn or two and everything is perfect. Note that I only do this to the arms. I do not ream the front yoke (c-hub) or rear hub carrier. You want the pins to pivot in the arms not in the hubs.

The Kwik Klips use to set the wheel base can be a tight fit. I sanded one on each corner with some 400 grit paper to make them a perfect fit.

When you are all done you wan the suspension to drop freely under it own weight with no tight spots.

When you get to the front hubs pre thread the king pins. If you do this out of the yoke the pins will self center and end up perfectly aligned.

Take the yoke and using a tapered reamer ream the king pin bore so its counter bored for ~1/3 of ot depth. Do the same from below on the lower king pin hole for ~1/3 of it depth. Our yokes are beefy and are very strong compared to other cars. The material you remove will have no effect on durability but it will make the front hub turn very freely.

When you have the front end together each hub should turn freely with no tightening or binding at full lock in either direction.

In the last pic some of you will notice I secure my outer hinge pins with a pinion setscrew. PW runs his car stock with e-clips. I like the setscrews. Its a personal prefrence on my part.

If you want to use set screws carefully drill a 2.5mm hole from the bottom up on the front yokes and rear hubs. Grind a corresponding flat on the hinge pin. When you tighten up the assembly just snug them up so the pin is secure. You can strip them out if you over do it. But...if you do strip out the hole you still have e-clips.

As far as tips I have covered them all. The rest of the assembly steps are straight forward.

For more details and questions asked during this online assembly guide for the Schumacher MI3, refer to this thread

Pour les francophones, toutes questions relatives à cette voiture peut être poser dans ce sujet spécifique.

Regarding Schumacher MI3 manual ans set-up sheets, you can find a large amount here, combining the official Schumacher data and search results on various forum!