Help with dial indicator

[Dunc]

Was given a Starrett 196 dial indicator.The plunger moves smoothly (no rough spots) but not freely. I can gently pull the plunger back to its home position but it will not return of its own accord. There is no sign of any rust on any piece in the set. Rather than an internal mechanical problem, I think it more likely that it is gummed up by gunk.

Is this d-i-y doable? Thinking of flushing the opening the plunger enters. Yes/no? With what? Lubricate afterwards using?
Is it necessary to open the housing? How?

Given it cost me nothing & I think it is salvageable, I am willing to pay for repairs instead of wrecking it with ham-handedness. Then again, if repairs approach the cost of a new one...

[pinstripe]

Starrett 1620 Tool and Instrument Oil. I bought mine from Amazon for $7.50 a couple of months ago. Now it's $36.99! I think it's because Amazon is out of stock and third parties are selling it.

It looks like light machine oil to me. I doubt there is anything special about it. Certainly not $36.99 worth of special.

[Steve Steven]

I have some Watch Oil, not the sperm whale type but the synthetic replacement, I'll send you a bottle (its a small bottle, less than an ounce) that is non-sticky much better than Staretts tool and instrument oil for fine movements. PM me if interested.

Steve

[J Tiers]

many folks suggest NOT lubricating it. Cleaning with solvent and letting it be.

I'm not sure I'm in agreement, but for sure, clean it out with a solvent first. If you are not disassembling, then cleaning is harder, but letting some wick in, then absorbing it with paper towel held against the gap, repeated until it comes out clear would be a good start.

Then, depending on which camp you believe, either letting it dry, or putting in a slight amount of the Starrett oil, or watch oil. I have used the Starrett oil and nothing has gummed up yet.

I do NOT think more oil on top of whatever gummy stuff is in place is a good idea. Does not usually work well.

It's possible that the problem is not with the plunger itself, but with something inside. In that case, clean and lube for the plunger alone won't fix it.

There is a place for oil, and a place for NO oil. For instance, the Last Word (and also, I believe, the 196, inside) has a sapphire rod that turns a worm to make the pointer move. That should never be oiled.

[JCHannum]

The best advice for DTIs is no oil, it will just accumulate dust and create gunk. To clean try lighter fluid in copious amounts to flush out gunk around the stem. The 196 has a stout return spring and it usually takes quite a bit to foul it.

[MikeL46]

I used a little Kroil on mine. Freed it up, and that was several years ago and it is still free.

Mike

[10KPete]

Like others have said; no oil on a Last Word. If you can remove the back, do the cleaning from inside trying to keep the cleaning fluid out of the dial side. I prefer lighter fluid. I use that on pocket watches also. If there are pivots or gears to oil, use watch oil (not clock oil) or a really good substitute for indicators is LPS-1, applied sparingly. It's a really good, light lube. Spray a little in the cap and apply with a little brush.

'Nuf said by me!

Pete

[Frank K]

If you do decide to have someone else clean and rejuvenate it, I can heartily recommend longislandindicator.com. I've dealt with them several times. They're quick and reasonably priced.