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Shock revalve

CRAFT Racing

Active Member
I was working on my buggy the other day with a friend and we thought this might be helpfull. We're not trying to explain shock dynamics or theory here, just a basic how to type thing so those who have never done a shock revalve can attempt it themselves. Feel free to PM me if I missed anything or you have any suggestions. I would like this to be as informational as possible.
Jon
 

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Random Thoughts Racing

Well-Known Member
Here are a few suggestions on tools or technique.

To test shock for problems before beginning work
-After removing coil spring place shock verticaly in vice and slowly depress rod, feel for any binding, if rod extends again after this the divider oring may have failed and the oil cavity is pressurized. Recharge with nitrogen to fully extend rod, look for smooth extension. This will ensure that the divider piston is in the same position as when it was assembled (assuming no leaks or air in the shock).

-Step #9 Rebound caliper photo shows some "grit" or something on the table. Suggest laying out valving on a clean towel, wiping each shim clean, and inspecting them before reassembly.

-As valve stack height grows the top spacer height may need to be reduced to ensure proper nut engagement.

-Dont flip piston over or install valve stack upside down on reassembly (it happens).

-Step #13 oil top off - if the shock was dissassembled while somewhat compressed the oil level will be abnormally low as the divider piston is not in proper position adding to much oil at this point could cause catastrophic shock failure.
 

Beat98TJ

Well-Known Member
Looks ok. Remember that cleanliness is key. If possible clean the shock in a solvent tank or wipe it off with brake clean before disassembly. Also I brake clean and wipe each disc and the piston before reassembly.
 

Kritter

Krittro Campbell
-As valve stack height grows the top spacer height may need to be reduced to ensure proper nut engagement.
Dont go too thin or the Rebound fulcrum washer will become a variable in your valving rather then just a fulcrum diameter...


-Dont flip piston over or install valve stack upside down on reassembly (it happens).
Ive got 4, 3.0 race shocks in my garage that are from the factory with pistons in upside down...I wont mention names though, but they arent blue and they are not black...
 

shamrock

Member
The original post has the COMPRESSION valves on the top and the second pic I put up has the REBOUND valves on top . Which one is correct ?
Thanks
 

CHASE550

Well-Known Member

motochris

Well-Known Member
The original post has the COMPRESSION valves on the top and the second pic I put up has the REBOUND valves on top . Which one is correct ?
Thanks
Compression valving is on the shaft side of the shock, rebound on the body side.
 

CRAFT Racing

Active Member
Also, if you take it apart and get confused which way is up.....the rebound side will start at 1.60'' and the compression will start with 1.80''. The piston is machined that way as well.
 

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PSWPete

Member
-NEVER (not even by hand) cycle the chock when it is not charged. One way to tell if the dividing piston has failed is to shake the shock. If it has failed you will hear fluid sloshing around.
-When re-assembling the shock, after the rod-guide snap ring has been replaced, charge the shock to seat the rod guide before tightening the dust cap. DO NOT PULL the assembly up. It usually takes quite a bit of force to move the dividing piston in the res.. If you try to cycle the shock when it is not charged, the dividing piston will usually stay stationary, and the end cap attached to the hose will travel in and out of the res.. Any dirt or grit on the end cap o-ring surfaces will cause damage to these o-rings, eventually causing them to fail.
-Try to use "V" blocks and a press to hold the shaft when removing the valving stack nut. Otherwise the shaft will start to loosen from the end-loop. I have seen this happen a lot on (not blue/black) shocks.
 

Beat98TJ

Well-Known Member
-NEVER (not even by hand) cycle the chock when it is not charged. One way to tell if the dividing piston has failed is to shake the shock. If it has failed you will hear fluid sloshing around.
-When re-assembling the shock, after the rod-guide snap ring has been replaced, charge the shock to seat the rod guide before tightening the dust cap. DO NOT PULL the assembly up. It usually takes quite a bit of force to move the dividing piston in the res.. If you try to cycle the shock when it is not charged, the dividing piston will usually stay stationary, and the end cap attached to the hose will travel in and out of the res.. Any dirt or grit on the end cap o-ring surfaces will cause damage to these o-rings, eventually causing them to fail.
-Try to use "V" blocks and a press to hold the shaft when removing the valving stack nut. Otherwise the shaft will start to loosen from the end-loop. I have seen this happen a lot on (not blue/black) shocks.
I agree with this. Most reputable rebuilders I know make this mistake. I always have some pressure in the shock even if it is 25psi to keep the seals energized. I also push the rod out with pressure, never by pulling.
 

Beat98TJ

Well-Known Member
Compression valving is on the shaft side of the shock, rebound on the body side.
I always tell people that rebound is the nut side. Seems to work usually.
 

therail

Well-Known Member
-Try to use "V" blocks and a press to hold the shaft when removing the valving stack nut. Otherwise the shaft will start to loosen from the end-loop. I have seen this happen a lot on (not blue/black) shocks.
Ouch, I prefer to use aluminum vise jaws that are cut for shock shafts. Racetech sells them for bikes/quads, I don't know where you would get a set for some truck shocks.
 

PSWPete

Member
Let me clarify, Aluminum "V" blocks. I have blocks that are cut for different diameter shock shafts. These are a must for changing out the ends on bump stops. It's difficult to get enough clamping force with a vice. A press is the way to go.
 
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