R390 Gear cleaning and lubrication

[ke7trp]

I am rebuilding an R390 for use with my T368.  The gears and packed with Cruid, hair, dirt and old Grease.  The manual tells how to clean these gears but does not tell what to use.  It says Cleaning compound and "GL" for the Lube.

I have used NON clorinated Brake cleaner for years on electronic parts and plastic parts. Never had a problem.  What have you used?

I would guess that GL means Gear lube.  What have you used in the past with good results?  They mention a Grease Gun.  To me that would be automotive Chassis Grease which I have.  Or do you suggest a light oil?  Maybe Moly lube?  Or the white automotive grease?

My worry here is that I wont have the right grease to put back in place. This could create a geartrain that is to easy to turn.  I have had bad luck in the past trying to service FT101 gear Drives. They seem to loosen up to the point the VFO knob wont hold its position.  I doubt this would be the case with the 390 since its moving alot of cans up and down in action.

I thought I would make a post and find out what is proven to work..

Thanks alot!

Clark

[WV Hoopie]

Clark,

Never played with a R-390, but I've had several of the "A" gear train spread all over the bench & floor . Check out Scott Seickel's excellent "R-390A Gear Train Rebuild" Tutorial. Lay the parts out in logical order, clean, then reasemble in reverse.
http://www.r-390a.net/faq-refs.htm

The pics might help with your project. As for lube, synthetic motor oil has been used with great results. Mobil 1 for the gears, 90 weight synthetic for rollers on the racks.

Craig,

[n2bc]

Never done a "non-A" either, but many "A"s. 

I second the use of synthetic lubes and add the following:

1) get everything CLEAN, really clean.  I've taken a couple really nasty gear trains to the D-I-Y carwash first. Disassemble as much as you are comfortable with - I've always had the good fortune to have a second unit to look at. Then clean the disassembled pieces - use whatever you have that will cut the old lube, you can't hurt the gear train (stay away from sulfuric acid and sand blasters I suppose).

2) re-lube SPARINGLY.  A touch of oil on rotating parts, a dab of grease on sliding parts - SPARINGLY

I picked up a "Hobby Kit" of lube here: http://www.lubekits.com/?load=hobby
A bit pricey ($25ish) but the applicators are very handy and between the two oils and tube of grease, it's a lifetime supply.

Good luck!    73, Bill   N2BC

[flintstone mop]

I'll have to second the SPARINGLY part.
That's ashame about the crud.
I keep all my covers on and it is still spotless in my -A.
Prolly coz it never saw military service. It was gifted to a Ham from MARS for wiring their commcenter. Brand New in the original crate.

Fred

[Ed/KB1HYS]

Taking Digital photos of the assembly as you take it apart can be a life saver. Take more than you think you need, as there always seems to be that one part you don't quite rememeber...

I cleaned my R-390A gears with WD-40 (with the red tube when needed) and a rag with out disassembly. Just don't be sloppy.  Ran smooth and much more freely when done.

If it was sticky I would have used PB Blaster!

[ke7trp]

I was not planning on taking the gears apart. I was planning on following the army maintenance manual.. Long Brush and cleaning fluid

I will try it today.. I have Grease and some Royal Purple Gear oil for the race car in the garage..

Thanks for the help guys!

C

[k4kyv]

Make sure the little roller bearings, which roll over the cam edges, turn freely.  If they freeze up, they slide along the cams instead of rolling.  This wears flat spots on the roller, so that even after the bearing is cleaned and lubricated, it still stops rolling and begins sliding at the flat spot.

[ke7trp]

Thanks for the tip. I will let you know what happens

C

[ke7trp]

WOW..   What a difference! 

I used a can of autozone brand non clorinated Brake cleaner.  One thing I want to mention is that you MUST remove the Front FREQ cover.. Otherwise, You will blow crap into the lens.  Remove it before you proceed.  I had to go through the trouble of cleaning it out.

A TON of GRIME came off those gears and sliders.  I used Lithium Grease on the sliders and cams using a piece of WIRE to apply. I used Turbine oil on the gears. Its smooth and requires a tenth of the effort now.  Very smooth. 

I got the knobs in also.  This one is really shaping up!

C