Generational Changes in Repair Stands
This article will discuss the generational changes in repair stands. There have been running changes made through the years on several models. Some models are now discontiued. To find PDF parts diagrams, search for the stand model at: http://www.parktool.com/library/document
PCS-1 and PCS-2 Home Mechanic Repair Stand: produced post January 2002
The PCS-1 and PCS-2 Home Mechanic Repair Stands have been several changes through the years. The piece at the top of the vertical tube is called the top tube. It is made of a composite material and is secured to the vertical post by bolts. There is a lever behind the top tube that rotates to tighten the clamp into the top tube to control rotation.
The clamp used in is verision of the PCS-1 and PCS-2 Bench Mount is the 100-1C. There are internal threads at the back of the clamp that fit a thread inside the top-tube. A cone-shaped sleeve (#149) fits between the clamp and the top tube. The 100-5D MIcro Adjust Clamp will fit this top tube as well.
The top tube part number of the current PCS-1 is the #939C, the "Universal Top Tube-Complete". This model has the number "939" embossed behind the handle, as seen in the image below.
The 100-1C clamps produced as of January 2002 are different than previous clamps. All 100-1C clamps use an internal threading in back of the tapered "donut". The current clamps have a protrusion that extends the threads, as seen in the image below.
PCS-1 and PCS-2 Repair Stands- produced June 1996 to December, 2001
The top tube of this generation will fit the 100-1CA clamp only. The design of the top tube is not interchangeable with the 939C described above. There is no part number embossed behind the handle.
The clamp for this generation is called the 100-1CA. There is no extension behind the tapered donut. This clamp is not interchangeable with the 100-1C. There is no other clamp that will fit this stand generation. See the image below.
PCS-1 and PCS-2 Repair Stands produced pre 1996
The PCS-1 and PCS-2 made before 1996 used a steel top tube that is welded directly to the vertical post, as seen in the image below. There is a threaded lever (Part #191-2G) at the top of the top-tube to control rotation of the clamp.
The pre-1996 PCS-1 and PCS-2 stands use the 100-2C clamp. There is no internal thread behind the donut. There is a one-half inch stud extending behind the clamp. There is also a recess machined into the donut of the clamp, sometimes refered to as a "groovy donut". These clamps will not fit with the current PCS-1 and PCS-4 stands. There is no other clamp that will fit this stand generation.
PRS-5 Professional Race Stand: Current model produced as of January 2002
The PRS-5 Professional Race stand uses the 939C top tube described above. The clamp is the 100-5C.
The current PRS-5 uses a black vertical tube. The height adjustment is controlled with a quick release mechanism. The bracket that holds the vertical tube is the #935R Center Yoke. This yoke is not interchangeable with the older PRS-5 stands.
PRS-5 Professional Race Stand: 1996 to 2001
The PRS-5 from year 1996 to current uses the 100-5C clamp. The top tube for these stands is the 939-5C. The vertical tube for this generation is blue oval tubing. The yoke bracket that holds the vertical tube is #935. The height adjustment is done with a round knob.
Pre-1996 PRS-5 Professional Race Stand
The first generation of the PRS-5 used a steel top tube, similar to the PRS-3 stand. The clamp used of the pre-1996 PRS-5 was the 100-3C. The lockblock system secures the clamp from rotating, and used a round knob to secure the clamp in the top tube.
Pre-1996 PRS-6, PRS-7 and PRS-8 Professional Repair Stands
The older PRS-6 and PRS-6W. The locking mechanism is a part #191C positioning knob and shaft, and secures vertically through a threaded fitting at the top of the stand head. The clamp used was the 100-8C, which has a machined recess to accept the 191C swivel foot. The pre 1996 PRS-6 is shown below. The PRS-7 (bench mount) and PRS-8 (wall mount) are of similar design.