[s-cars] Creeeeak, creeeeeak, creeeeeeak -Tired of those noisy rear link joints?

[Igor Kessel]

Fred Munro wrote:

> 	Well, after 6 months one of my newly replaced rear upper link outer heim
> joints started singing that old familiar tune. My past approach was to stick
> a grease needle through the seal and pump it full of grease. This works, but
> eventually the seals are full of needle holes. This time I decided on a
> different approach.
> 	The ideal fix would be to drill the outer joint for a grease fitting, but
> there is not a lot of metal there and I've been kind of leery about drilling
> a hole large enough to take even a small grease fitting in case it weakened
> the joint. I took a micrometer to my grease needle and picked a drill 0.002"
> smaller (No.51 in my case). I drilled a hole through the top of the joint's
> outer housing and then drilled a larger hole just long enough to make a
> couple threads for a (very short) stainless 6-32 machine screw to seal the
> hole.
> 	Inserted the needle, pumped grease until it came out of the seals, and
> inserted the sealing screw to keep the grease from coming back out of the
> hole. Ah, blessed silence. Wait, what's that pool of oil under the car -
> arghh, the left side diff seal is leaking.....
> 	Did discover a few things about these joints. The OEM joint has a heavy
> plastic insert between the inner bushing and the outer joint case. The
> cheaper aftermarket replacements I bought are metal on metal - no plastic
> insert. Maybe that's why they started squeaking in 6 months and it took the
> OEM joints 9 years. Maybe there is a reason the OEM joints are more
> expensive....

Fred, how deep was the metal cap of the join?

I have just done the same exact thing with the notoriously squeaky lower 
control arms in my wife's A4. I used the M6x1mm, 90° grease fittings 
from McMaster (1105K76). They come in a package of 10.

The cap thickness in one arm was 6.5mm, in the other was 7.5mm. The 
grease fitting itself was 6.5mm long so in the first case I used a small 
metal washer. I also put the Red Loctite on hate thread. It's the one 
that is permanent.

So far so good. Sure beats replacing 4 lower arms at $300/ea and doing 
the alignment after that.

FYI folks, Pep Boys sells the 90° grease fittings with the 0.25" thread. 
I am not sure about the pitch, but given the choice I would recommend 
the fine pitch.
I didn't buy those and bought the metric ones from McMaster instead 
because I hardly have any non-metric tools in my garage, much less taps 
and dies.

-- 
Igor Kessel
two turbo quattros in the stable,
the third one is in the works