L300 Sun Roof Slow

[Morganizer]

I have an L300 low-roof with the sun roof over the middle seats. The sun roof opens and closes exceedingly slow. The motor is working very hard, and I always help it along with my hand. Which means I can't just reach back while driving and press the switch; have to climb in the back seat to open or close it.

I've tried the following:

1) spraying silicon lube in the aluminum tracks where the cables run. No change.
2) adding grease to the cables. No change.
3) removed the motor, cleaned the brushes and commutator with chlorothane, added grease to the gears, and reinstalled. No change.

It gets worse the wider the sunroof opens.

Where else could it be binding?

[TardisDeli]

The actual tiny motor there is aged, worn out. Often happens. Each opening window has its own motor.

Find an old guy who used to rebuild stuff like alternators (you know, he's still got that lovely old car in the garage) or ham radio operators (you know, that house down the road with the huge radio antenna on the roof) to rebuild the guts.

Don't know anyone who has fixed it. Jay just tells people to enjoy it while it works, and take a video to watch later when it no longer works.

Sounds like you've done more maintenance than any one else, to actually clean the brushes and commutator (good on ya'!). And yes, it gets slower the further it opens due to engine load of moving the whole heavy glass that long distance.

Let me know if you find a resource to fix it so we can tell others.
Christine.

[Growlerbearnz]

Mine did that, it was due to someone lubricating the sliding tracks with grease rather than graphite or other dry lubricant. The grease gets full of dirt and turns into sticky sludge. It's unlikely to be the cables, they don't tend to stick. The motor's safety clutch often fails, but that sounds like the motor working easier rather than harder.

Due to the way the rear guides work, there's a danger your glass will get jammed in the open position if you don't resolve the situation- when the glass hits the front edge of the hole, the rear guides keep moving a bit more and a mechanism lifts the glass up. If the front guides get jammed with the sunroof open, then the rear guides may lift the glass while it's still inside the van- which jams the glass into the underside of the roof. Not good.

Remove the glass (take off the 4 plastic covers inside then undo the 10mm nuts, take note of where the adjustment spacers are so you can put them back in the same place) then, while you're standing in the sunroof hole, you can remove the front guides and start cleaning out the aluminium guide channels. The front guides have plastic feet that run in the channel you need to clean, you'll want to clean those plastic feet too.

You'll need a rag on a stick and plenty of solvent- I used turpentine because it's oil based but still evaporates eventually. Clean as far back as you can. Moving the back guides back and forth will bring dirt out from the tracks at the back where you can't reach, but those tend to stay relatively clean. Remove the rear guides at your own risk, they're a cow to reinstall with the sunroof in place.

Once they're clean, lubricate the track and guides with graphite or other dry, non-sticky lubricant.

Good luck and take photos!

[Morganizer]

Thanks to all who replied. Having disassembled and inspected the motor, I'd advise others to not bother -- I couldn't find anything wrong with the motor, and don't think my little PM left it much better off. After 18 years of use, it's still clean inside, and there's lots of life in the brushes. Which means no need to remove the headliner to troubleshoot a sunroof.

I'm going to explore the second suggestion, that there's grease and dirt in the tracks that's gumming up the works. Sounds plausible: previous owner noticed the sunroof was slowing, greased the tracks and made it worse.

Now, it seems to me you're talking about three areas that require lubrication:

1) the aluminum track that the cables run in
2) the copper tubes that the cables run in
3) the guides that the glass sunroof runs in

Are you recommending dry lubricant on all three? That would mean I'd have to clean grease out of the copper tubes (ugh).

I'm wondering has anyone replaced a sunroof? How much work is that? Might be easier (having come this far) to just take it down, clean it, and reinstall.

[Growlerbearnz]

The cables, whether they run in aluminium or the copper coloured tubes, should be greased. It's unlikely that they are gummed up though, they don't experience much friction and are fairly well protected from dirt.

The sliding channels should be cleaned and lubed with graphite.

Here, I made a picture, though I left the glass in place:

[Growlerbearnz]

Oh, and removing the sun roof isn't all that difficult, but getting all those clips off roof lining without damaging them is a... well, it's not nice. Took me about 4 hours the first time, since you have to remove the curtain rails, seat belt top mounts, all the plastic trim front and rear, and both roof linings. I've done it a few times now and I'd say it takes me an hour, but it's still not pleasant.