Applicability: Any Johnson Transmitter using the Johnson Ball Drive Assembly
1) Johnson Ball Drive assembly uses 3/16" ball bearings (3)
2) We have found cases of the balls showing a "flat spot"/galling resulting in a "glitch or hesitation" in the ball drive input shaft rotation
3) This "flat spot"/galling results from over-tightning of the outer tensioning nut which crushes the wavy-washer, resulting in the balls in the assembly being "dragged rather than rotating" in the input shaft concave drive recess.
1) Disassemble ball drive mechanism
2) Clean thoroughly
3) Replace the three balls ( McMaster Carr has these: 3/16" stainless balls)
4) Polish the input shaft concave ball drive recess ( We chuck the ball carrier assembly in a drill motor, polish the concave drive recess with 1000 grit wet or dry) rinse and dry.
5) Carefully re-tension ( bend) wavy washer. If wavy washer is missing, McMaster Carr has a suitable replacement.
6) Re-assembly ball drive assembly, don't be stingy with lubricant ( we use lubriplate)
7) If your Ranger does not use a "floating snubber", and the ball drive uses the front panel as a support structure, tighten the "tensioning nut" only enough so the dial pointer rotation is smooth and does not "skip" .
On Fri, Jul 28, 2023 at 06:25 PM, Ashley Hall wrote:
Applicability: Any Johnson Transmitter using the Johnson Ball Drive Assembly
?
1) Johnson Ball Drive assembly uses 3/16" ball bearings (3)
2) We have found cases of the balls showing a "flat spot"/galling resulting in a "glitch or hesitation" in the ball drive input shaft rotation
3) This "flat spot"/galling results from over-tightning of the outer tensioning nut which crushes the wavy-washer, resulting in the balls in the assembly being "dragged rather than rotating" in the input shaft concave drive recess.
?
1) Disassemble ball drive mechanism
2) Clean thoroughly
3) Replace the three balls ( McMaster Carr has these: 3/16" stainless balls)
4) Polish the input shaft concave ball drive recess ( We chuck the ball carrier assembly in a drill motor, polish the concave drive recess with 1000 grit wet or dry) rinse and dry.
5) Carefully re-tension ( bend) wavy washer. If wavy washer is missing, McMaster Carr has a suitable replacement.
6) Re-assembly ball drive assembly, don't be stingy with lubricant ( we use lubriplate)
7) If your Ranger does not use a "floating snubber", and the ball drive uses the front panel as a support structure, tighten the "tensioning nut" only enough so the dial pointer rotation is smooth and does not "skip" .
?
Hi Ashley.? I'm currently restoring a Navigator and the ball drive is rather rough.? Maybe you can explain what needs to be done to get the ball drive mechanism out of the VFO.? I know there is in insulated shaft coupler on the VFO tuning shaft, but there seems to be no way to get to that without removing the VFO assembly from the chassis.? I've never had one of these VFOs (Ranger or Navigator) off of the chassis, so any tips you may have on that would be appreciated.? I'm going to order the new ball bearings from McMaster Carr.? Thanks much for identifying the size and source.? When I lived in Raleigh, we had a bearing distributor who sold nothing but bearings and I used to just take a worn bearing in and they'd identify the exact material and size for me.? No such luck here in the mountains of northwestern NC.??
Well, I discovered the hole in the chassis that allowed me to get to the setscrews on the coupler, so now have the ball-drive out.? But, so far have not been able to see any way to take it apart.? Maybe you can tell me the secret!
From:[email protected] <[email protected]> On Behalf Of Floyd - K8AC via groups.io Sent: Friday, April 25, 2025 1:38 PM To:[email protected] Subject: Re: [EFJohnson-Amateur-Radio] Johnson Ball Drives, Ball issues
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Well, I discovered the hole in the chassis that allowed me to get to the setscrews on the coupler, so now have the ball-drive out.? But, so far have not been able to see any way to take it apart.? Maybe you can tell me the secret!
On Fri, Apr 25, 2025 at 08:56 PM, David Harmon wrote:
Watch some D-Lab videos¡.he shows how to do it.
As you know, there are dozens or maybe hundreds of D-Lab videos.? I've probably watched them all, but never saw one dealing with disassembly of the drive.? The problem is that the same drive was used in many Johnson models, so he may indeed have described the process when dealing with one of the models I'm not interested in.
On Fri, Apr 25, 2025 at 02:38 PM, Floyd - K8AC wrote:
Well, I discovered the hole in the chassis that allowed me to get to the setscrews on the coupler, so now have the ball-drive out.? But, so far have not been able to see any way to take it apart.? Maybe you can tell me the secret!
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For others who pass this way with the same question, the threaded portion of the drive unscrews from the large nut housing, but - they used some form of Loctite to glue the two together and you'll NEVER get it apart unless you heat the large nut to break down the glue.? I used a Harbor Freight heat gun and after getting the thing very hot and then holding the threaded portion in a small vise with plastic jaws, it came apart fairly easily.??
After getting the ball drive apart, I followed Ashley's steps closely and the result is a VERY smooth turning drive.? I was able to turn the 1/4 inch shaft by hand with no knob and it felt? smooth with just a slight touch of roughness in places.? With the knob installed, it feels perfectly smooth.? I took a chance on the ball bearings not being damaged as I didn't have the patience to wait for new ones to arrive.? I used Park brand bicycle grease that's used on wheel bearings to reassemble the drive.??
Floyd - K8AC