Sorry, link works here. I'll just cut and paste it here for ya.
This was originally posted by Quadzillaracer (Justin)
I have received a few emails over the past week since the post from hell, asking how to blueprint a chassis and what it means and what are the benefits. Without trying to piss anyone off I'll give my take on what has worked for me over the years.
Depending on how much ditch banging abuse and jumping over the years can have a great effect on how much work will need to be done to correct your chassis. The basic idea of "blueprinting" is to make the drivers, chaincase, and jackshaft move freely without friction between the sled and ground.
I generally like to start by spinning the mounted jackshaft without gears or chain to feel for basic friction in the shaft, bearings, ect. Many times to align the jackshaft with the chaincase housing requires the use of shims under the mounting pads. They will need to be different thicknesses and I like to notch and use washers for the shim.
After I get the jackshaft rolling -SMOOTH-, I focus on the relationship between the chaincase and drivers. You want the drive shaft to roll free, this generally requires skimming the chaincase out or notching the chaincase mounting holes to slide the actual case forward or back, whatever is needed.
Now after you have the drivers spinning smooth... you may need to go back and re-adjust the jackshaft. After you have determined that the drive system is spinning smoothly and friction free, I focus on the tunnel and suspension. Now all your measurements should come off the newly aligned driveshaft.
I start by checking the factory stamped mounting holes in the tunnel, (they are sometimes off from the factory.) This may require egg shaping the holes to adjust suspension. You'll have to measure parellel on both sides from the front mounting holes to the drive shaft itself, then check the rear mounting holes. After you have determined that the mounting holes are true to the drive shaft. Focus now on the actual skid frame.
I check the squareness of the skidframe by taking corner measurements and you may need a grinder to remove off the ends of the mounting shaft to get square. Also check parellel measurements... may need some minor tweeking.
Now your drive train should be friction free. Now when you adjust your track tension it is also a fine line. If you tighten it to tight you'll lose your rolling resistance creating pressure on the drivers...if the track is to loose you'll ratchet the track. I start loose and tighten the track until the track doesn't ratchet and I retain the track moving freely. Now you may have to re-align the clutches or engine because you have changed the position of the jackshaft alignment to the primary clutch. This is a game of patients and may take 10-14 hours, once you start don't stop!!!
When I aligned my Turbo V-4 it took 12 hours...this was a mint chassis with no abuse. I ended up leaving the jackshaft alone but had to slide the chaincase up and back 1/16" and I used a Wahl Suspension which required me to turn off (aluminum) 1/8" off mounting tube to square true. Well there may be more minor things to do this should give you an idea how to make it work. I know that I can sit with the warm up jackstand and roll the track with 2 fingers.
Your reward should be an additional 5-10 mph gain (depending), quicker upshifting and better life on components. This will be the cheapest and best gain you'll ever make. If you don't feel confident enough to tackle this job I wouldn't...takes lots of patients and time, but well worth it. Oh yeah... don't forget to realign the skis to the newly aligned track!
Shark
