What lube for inside tailgate lift motor?

[Darragh1]

Hi,
After many months I have gotten round to removing a broken one and will be installing a used tailgate lift motor. Before I want this one to last so I need to make sure it is lubed properly.
If you look at the photo- There is a metal and plastic gear on top which seems like it has never been lubed or should not be? There is the main gear with window regulator type teeth which has a light smear of some grease dating back to its manufacture in 2012. And underneath there is a little white cog with some old yellow looking oilyness on it.
For the longevity of the mechanism, which lubrication should I use where?
Thanks for listening,
D.

 

[Bellow]

What do MB recommend?
The white cog - does it actually drive (the main mechanism)?
Where exactly did the previous one fail?

 

[Darragh1]

What do MB recommend?
The white cog - does it actually drive (the main mechanism)?
Where exactly did the previous one fail?

I was hoping someone might recommend the MB recommendation to save me calling MB.
I don't know if the white cog drives the main mechanism, surely it drives against a metal gear but i'll take another look.
The ball snapped off where it attaches to the gear and the housing of the motor shattered where it broke through.
I might crack the broken one tonight for a look...

 

[BlackC55]

I would use MB's sunroof grease.

 

[Bellow]

I was hoping someone might recommend the MB recommendation to save me calling MB.

Maybe you have that in post # 4.

I don't know if the white cog drives the main mechanism, surely it drives against a metal gear but i'll take another look.

I don't think it does but academic as it can be lubricated with the others.

The ball snapped off where it attaches to the gear and the housing of the motor shattered where it broke through.
I might crack the broken one tonight for a look...

That is a catastrophic failure and it occurring right at the gearbox's output looks as though it could have been overloaded. I'd check this out before installing a replacement or it could be a repeat occurrence.

Re suitable lubricant. In the absence of a specific product recommendation I'd be looking at a lightish (NLGI#1) non EP grease from a tin/tub/cartridge applied with something akin to a spatula. If you get the choice of thickener/soap base, aluminium complex is nice and fluid. Don't be seduced by 'lithium' grease - 99% of greases you encounter will be lithium based and avoid aerosols unless 100% certain the carrier (probably a solvent) wont attack the plastic parts or allow the grease to permeate the motor.

 

[Darragh1]

...

 

[Darragh1]

Can of worms?
I opened the broken unit. Probably due to wear and tear and maybe over the years people 'assisting' the tailgate by hand:
The leg with the ball and socket probably loosened from the main gear and then because of this 'play' and further use the ball twisted out of and mangled the socket and then was stressed against the housing of the motor and with further use got caught and shattered the housing.

The white cog underneath is driven by the elcctrical motor. The main moving part with the teeth is driven by a metal? gear underneath the four cog part.

On the broken unit and on the new used one I see no evidence of lube on the black plastic cog on top nor on the four cog part. There is a little on the to lid of the unit where it secures over two mounting points.

Also there is no other broken part. All other internals look good.

If I was to avoid the MB grease option, can I have an over the counter motor factors alternative for the metal and plastic parts?

Thanks guys,
D.

 

[Bellow]

Can of worms?
I opened the broken unit. Probably due to wear and tear and maybe over the years people 'assisting' the tailgate by hand:

Crossed my mind that the destructive force was from the other direction - or possibly just overworked (stuck with ice/covered in snow/etc).

The leg with the ball and socket probably loosened from the main gear and then because of this 'play' and further use the ball twisted out of and mangled the socket and then was stressed against the housing of the motor and with further use got caught and shattered the housing.

The white cog underneath is driven by the elcctrical motor. The main moving part with the teeth is driven by a metal? gear underneath the four cog part.

I'll confess - I can't make sense of the mechanism. But the teeth on the white cog appear too flimsy compared to the others but as I said, I don't have full comprehension of its MO.

On the broken unit and on the new used one I see no evidence of lube on the black plastic cog on top nor on the four cog part. There is a little on the to lid of the unit where it secures over two mounting points.

OEM grease application in one word - stingy.

Also there is no other broken part. All other internals look good.

If I was to avoid the MB grease option, can I have an over the counter motor factors alternative for the metal and plastic parts?

Thanks guys,
D.

Often as not grease is supplied in plastic tubs or cartridges so shouldn't be a problem re plastic gears.

 

[Darragh1]

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[Darragh1]

The destructive force was probably after years of people trying to open it manually and shunting it open or closed. When the lever finally broke through the housing I may have caused that in a panic in the rain when it wouldn't close because the ball had broken away from the main gear.

 

[Bellow]

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Nope, still don't understand it!
Progress though - I now see what I thought was the motor isn't and the white cog is part of a worm drive - which kinda changes things. Worm drives have high rubbing friction at the worm and you definitely do not want heat there on a plastic wheel. I'd want specific information on the recommended lubricant before considering another. The Technical Data Sheet for the product will have the relevant info. Post a link to it and I'll take a closer look.

 

[Darragh1]

So is mb sunroof paste effective for all the plastic and metal parts inside the motor?
Mercedes sunroof paste:
As per Post #19 in

MB paste sunroof.

www.benzworld.org

Quote
From MB BEVO
Lubricating paste, Sheet 269.2
For slide shoe lubrication on sliding roof

MB 269.2 - Complex grease (NLGI grade 2, Specification 269.2) - Mercedes-Benz Specifications for Operating Fluids

MB 269.2 Gleitpaste A 001 989 14 51 Daimler AG, Stuttgart/Deutschland

General grease guidelines
Mercedes-Benz Betriebsstoff-Vorschriften

 

[Petrol Pete]

Is this an actual 'service item' in the eyes of Mercedes Benz ? usually drive units like this have one P/N and the dealer will sell you the whole thing but none of the gubbins inside.

It's usually down to some enterprising person on the internet suppling 'home made' parts to those who wish to repair DIY.

In some drives like this the 'plastic' gear is sacrificial, the 'weak link' that is designed to fail when the mechanism comes under too much stress.

Apropos of nothing . On one of the machines I often work on a particular gearbox has an electrically controlled overload , then a clutch and if it all goes 'Pete Tong' a brass pin shears off bringing the whole thing to a safe (ish) stop.

More than once I have arrived on site to find the local engineers halfway from removing the whole unit , bit's everywhere , only to find out about the shear pin way too late.

Remember , men do not read the instruction manual

Thread hijack over.

 

[Bellow]

Find the Tech Data Sheet for the MB grease recommended for sunroof here >> Renocal FN 745_94 - Fuchs Lubricants

It has a calcium thickener base. Calcium bases are chosen (usually) for their water resistance. NLGI # appears to be between 1 and 2. Normally that would be expressed as '1.5' but not here.
I'm not really seeing the need for calcium base here - maybe for the sunroof if the greased components are subjected to water - but not in a sealed gearbox. That said, the suitability of the sunroof grease for the tailgate gearbox appears to be speculation - nothing directly from MB that I can see.
There's a thickener base compatibility chart in the included PDF. You have to trust that the quoted 'calcium' base for the Fuchs product is that and not one of the other calcium based greases if choosing another non calcium based grease. Or, be prepared to remove all remnants of the previous lubricant prior to applying the new (if the bases are not compatible).

 

[Darragh1]

Is this an actual 'service item' in the eyes of Mercedes Benz ? usually drive units like this have one P/N and the dealer will sell you the whole thing but none of the gubbins inside.

It's usually down to some enterprising person on the internet suppling 'home made' parts to those who wish to repair DIY.

In some drives like this the 'plastic' gear is sacrificial, the 'weak link' that is designed to fail when the mechanism comes under too much stress.

Apropos of nothing . On one of the machines I often work on a particular gearbox has an electrically controlled overload , then a clutch and if it all goes 'Pete Tong' a brass pin shears off bringing the whole thing to a safe (ish) stop.

More than once I have arrived on site to find the local engineers halfway from removing the whole unit , bit's everywhere , only to find out about the shear pin way too late.

Remember , men do not read the instruction manual

Thread hijack over.

hi, i checked with my local mb parts man and yes it is a sealed unit and non serviceable by mb so no detail available on grease.
i reckon too much extra manual 'assistance' and forcing of the tailgate eventually broke the ball and socket away from the main regulator inside the unit wheee is is braised or welded in and that is the weak spot. I simulate with a screwdriver In this clip the work of the lever with the ball and socket at either end

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As per photo below : However it happened red separated from where it was anchored at green. And the red separated from yellow.
Thanks,
D.

 

[Darragh1]

Nope, still don't understand it!
Progress though - I now see what I thought was the motor isn't and the white cog is part of a worm drive - which kinda changes things. Worm drives have high rubbing friction at the worm and you definitely do not want heat there on a plastic wheel. I'd want specific information on the recommended lubricant before considering another. The Technical Data Sheet for the product will have the relevant info. Post a link to it and I'll take a closer look.

Mb parts don't have advice as it is a non serviceable item. I think since it is probably inconclusive and I need to put the car back together, I will spatula what I can from the bad unit and apply it to the good unit and be done with it. I really appreciate your time given, thank you,
D.

 

[Bellow]

Mb parts don't have advice as it is a non serviceable item. I think since it is probably inconclusive and I need to put the car back together, I will spatula what I can from the bad unit and apply it to the good unit and be done with it. I really appreciate your time given, thank you,
D.

If you can retrieve enough grease.... If not, clean thoroughly (non-solvent cleaner) and get some bearing grease in there.
At the least, you have spare gears from the unit with the broken pin should the replacement eat its gears - unlikely as that is.

 

[Darragh1]

If you can retrieve enough grease.... If not, clean thoroughly (non-solvent cleaner) and get some bearing grease in there.
At the least, you have spare gears from the unit with the broken pin should the replacement eat its gears - unlikely as that is.

Perfect thanks.