Lately I’ve been fielding some questions on how I do maintenance on particular areas of my rides. Because of my background in Sprint Cars I have been told that I go farther than some but I can tell you the amount of time I spend is nothing compared to the weekly maintenance of Tim Allison’s number 11. With this installment I will go through the steps of a total rebuild on my Pro-Line Pro-Spec Shocks.
After getting my O-ring replacement kit, PN 6308-04, the first thing I do is to slime the O-rings. I use Sweep’s green grease and like it. Once that is accomplished I start to clean and then disassemble the shocks. Every time I touch the shocks I wipe them off, this is something that will help you in the long run. Dirt gets everywhere, everywhere, and that can affect your O-rings, oil and anything in between. Matt Hale has been a mentor of mine when it comes to cleaning my RC rides.
The dis-assembly process is fairly straight forward but some of the steps I take may be different. First of all I separate the shocks left and right. If it was on the left front it stays on the left front. Also, if the particular shock cap was on the left front it also stays there. Once I start taking the shocks apart the shock caps are up so the oil drains out. The same process is done with the shock bodies. If I am feeling frisky I’ll spray them down with Brake Kleen to completely clear the bodies of any residue but this time I didn’t go that far. On a side note, don’t put your face real close, Brake Kleen will burn your eyes. A friend told me that, because it surely wasn’t me that found out the hard way.
Now that we are ready to put the shocks back together, I take my time here, I grab my shock oil and VRP pistons. Since I haven’t run Stadium Truck in quite a while I will be guessing on what I want, so for the front I have 30wt and 1.6 pistons while the rear gets 25wt and 1.4/1.3 split taper pistons. I am using Yellow Pro-Line springs all around as a baseline as well. One step I take during assembly is to put the bottom cartridge together while on the shock shaft instead of pushing the shaft through after. John Bolton of Factory 1 helped me out with that tidbit. I also assemble the shocks in the order that they were taken apart, I almost always start with the left front and end with the right rear, and continually check how the O-rings feel during this process. Should they not feel right, I take that shock apart and start over. Something I also learned was to place at least one limiter on the shaft. This prevents the bottom of the piston from touching the shock body and having zero oil in between the two. In my experience the Pro-Spec Shocks do take a little more work and care to get the overall feeling dialed in that I want but it is more than attainable.
Now, the shocks are all together and ready for oil. Here is the hard part for some from what I have been told. Once they are filled with oil I pump the shaft up and done three or four times. Typically during a full rebuild you will have several air bubbles, some of which are large, and that takes some time to clear out. When this happens I find something else to do. I sometimes will walk away for as long as twenty minutes so every single bubble goes the way of the dinosaur.
Time to bleed. No not you, the shocks. This is a process that could take five minutes or it could take fifty. This is the only process where I do not complete all four and then start whatever process is next in line. For the first shock, typically my left front, I screw the cap on and then bleed out some of the air and excess oil. I wipe the shock down, and then move on to the next, left rear. Once I have finished the right rear I move back to the left front and bleed out more oil and air until I get each shock with zero rebound.
A full rebuild for me takes me well over an hour but it could easily be done quicker. Remember also that after a fresh rebuild it is a good idea to frequently check for air build up once you start running the next time at the track.