Pioneer SL-50a Turntable - What weight silicone lubricant in it?

redpackman

Active Member
Anyone know what weight silicone lubricant is used in the Pioneer SL-50a? It's used in the cueing and arm return mechanism as a damping agent. But what weight? Any info is appreciated. I have 120,000 weight available. Too thick or not stiff enough?
 
turntablebasics has 300,000cSt listed for the cueing mech on what they sell, i have no personal experience with the product but a video i watched from someone on youtube it seemed to do what it was supposed to do.
 
WD409, thanks for the input.

Here's what I found out:
OK, after some research, I'll answer my own question. The material inside the cover covering the rotator plate is silicone fluid. VERY, VERY, thick silicone fluid. I tried 125,000cST...not thick enough, not even close. I tried 500,000 cST because of a tip from WD409 (they didn't have 300,000 cST), and it seems to work pretty well. I had to clean out the old stuff with rags and paper towels and then put a dollop of this on the rotator plate and some in the rotator cover. Then replace the cover not forgetting the gasket. Now the cueing drop and lift and the arm return seem to be at the right speed. This material controls both actions from its little reservoir near the rotator plate.

You can often get this stuff at hobby shops that deal with radio controlled cars. They use this "fluid" in their differentials. It comes at weights even higher than 500,000 1 million and even more. It is exceedingly stiff at that level, but I guess it works in their trannies. When I walked into the moderate sized hobby shop and asked if they had silicone fluid. He asked, "Working on a turntable?" And they had nothing to do with audio equipment.

I've heard that 300,000 cSt works if it's to be used only in cueing mechanisms, but this Pioneer PL-50a is an odd bird and uses it in the arm return mechanism that doubles as the cueing mechanism too. I'll be honest with you. The PL-50a is a beautiful looking turntable, but it must have been experimental because Pioneer had more weird approaches to things with this model than I've seen before...and most of them don't work very well in my opinion.

I discovered I could have avoided all of this quest trying to fix the arm return function by lubricating the lever mechanism hinges. They'd become stiff and dried out in 40 years and slowed the whole works down (with an assist from the very stiff silicone fluid).

The turntable looks like a 10, but mechanically, after the years it becomes a 5 because of all the engineering bugs it has. Don't even get me started on its goof ball anti-skate mechanism.
 
I'll second the recommendation for 500,000 cst. I've used it in Technics and other turntables with great success.
 
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