Best method for lubricating a Macintosh Portable display hinge?

[Huxley]

Hi all! I just completed a "brain transplant" - I relocated the innards of my Macintosh Portable from the original badly-cracked bottom case to a replacement case (thanks again @ScutBoy!). The operation was a success and my Portable is looking and working beautifully now.

However, the hinge for the backlit display is very stiff - so much so that I get nervous every time I open, close or adjust it. I've seen a few comments here recommending silicone grease for PowerBook hinges, but I haven't seen anyone stating definitively that they've done the same for a Mac Portable display. If anyone has a suggestion on a safe and effective way to lubricate the Portable hinge without damaging the plastics or making it so easy to move that it loses the ability to stay upright on its own, I'd be grateful!

Huxley

 

[ScutBoy]

Hi all! I just completed a "brain transplant" - I relocated the innards of my Macintosh Portable from the original badly-cracked bottom case to a replacement case (thanks again @ScutBoy!). The operation was a success and my Portable is looking and working beautifully now.

Glad it found the right home!

 

[desertrout]

I'm wondering if the hinges just might need a thorough cleaning instead of the addition of lubricant... not really sure though, but I believe the hinges are just polycarbonate assemblies and didn't originally have any kind of lubrication. Maybe as a first step just flushing with IPA and working the assemblies?

 

[Huxley]

Glad it found the right home!

Thanks for helping make this happen!

I'm wondering if the hinges just might need a thorough cleaning instead of the addition of lubricant... not really sure though, but I believe the hinges are just polycarbonate assemblies and didn't originally have any kind of lubrication. Maybe as a first step just flushing with IPA and working the assemblies?

That's a really interesting idea / point. I guess I just assumed that the hinge would've shipped with some kind of industrial lubricant in there, but maybe not? I'm really curious if anyone knows one way or another...

Huxley

 

[Juror22]

desertrout said:
I'm wondering if the hinges just might need a thorough cleaning instead of the addition of lubricant... not really sure though, but I believe the hinges are just polycarbonate assemblies and didn't originally have any kind of lubrication. Maybe as a first step just flushing with IPA and working the assemblies?

That's a really interesting idea / point. I guess I just assumed that the hinge would've shipped with some kind of industrial lubricant in there, but maybe not? I'm really curious if anyone knows one way or another...

Huxley

In the Macintosh Portable Tech Procedures manual (p 2.26 Display Assembly) it does not mention anything about applying lubrication when re-installing/ re-assembling the clutch assembly.

 

[stepleton]

Some plastics can change shape over long intervals, and if parts of the Portable hinge have changed size by even slight amounts, it could become much harder for the hinge to rotate. I don't know how likely this is in this case, but I wouldn't be ready to rule it out as a possibility yet.

 

[desertrout]

So I'm going to walk back what I wrote earlier after looking at the hinges on my Portable more closely.... it seems they can come apart, though with some difficulty - requires squeezing together the 'split' part of the insert that faces outward, you can see one side has a snap fit edge - I didn't attempt this, nervous about it having no idea what to expect or how brittle the plastic will be). Looking in from that outward-facing side, I could see what looks like metal parts inside (I assume coils like the PB 1xx series hinges) as well as lubrication residue.

So, yeah, my assumption was wrong. Shocker.

My IPA suggestion still stands though, as some IPA might loosen up the old lube inside. Or WD-40 or something like that - you can access the internals from outward-facing side of the hinges, between the 'splits' (I have no idea if these words make sense to anyone but me...). Alternatively (or additionally) you could try adding some silicone lubricant through those same openings.

 

[3lectr1cPPC]

I’ve had luck using lithium grease on 100 series PowerBook hinges. It does take a while and several actuations (time seems to be the main factor) but my PowerBook 145 and 170 have both gone from a bit stiff to moving very freely.

 

[MacUp72]

Some plastics can change shape over long intervals, and if parts of the Portable hinge have changed size by even slight amounts, it could become much harder for the hinge to rotate. I don't know how likely this is in this case, but I wouldn't be ready to rule it out as a possibility yet.

thats right ..

Looking at the disassembly here , it seems that the whole hinge construction is made of plastics and over the hinge there is a bulky chunk of rubber stuck over it? when this is the case I would certainly lubricate that..all mechanical stability/usability is based on the strongness and also flexibilty there.