Gmc grease fittings

[SDM]

Have a 2011 GMC 3500 Duramax. Two of the grease fittings are hard to get to, would like to change to 90 degree fittings. Does anyone know the tread size of the fittings.

[wintersun]

The first time I greased the fittings on my Duramax truck it was a pain. Then I bought a Lumax 90 degree coupler and a new grease gun and it made it a relative snap.

The new grease gun was a Plews pistol grease gun so I could use one hand to hold the right angle fitting in place and the other hand to pump the grease. Well worth the $25 for the pistol grease gun.

I add grease every 3,000 miles and the truck really needs the grease at this mileage mark. No way could it wait for the oil change to be done.

[RCMAN46]

Bigfoot affair wrote:
#4 & 8, no zerks on the inner tie rods.

Thank You

[Bigfoot_affair]

#4 & 8, no zerks on the inner tie rods.

[RCMAN46]

Sport45 wrote:
Good info, but his 2011 should only have 9 fittings.

Post from LML Duramax Forum

Using benk's pictures which two are missing on the 2011?

[Sport45]

Good info, but his 2011 should only have 9 fittings.

Post from LML Duramax Forum

[BenK]

Never had a problem with my flex/rubber hosed grease gun. Yes, a good
one where the tip hangs no TIGHT. Mine won't come off if pulled straight
off...gotta pull at an angle

This application is a good one for Teflon particles or any of the solid
lube additives. Main or key to this is doing it often and never allowing
them to go dry. More so with the weight of a diesel or big block



This link is for GMT800, but it looks like my GMT400 and guessing
GMT900's very similar (corporate parts bin stuff)

There is a 12th, but not a zerk. it's on 4x4's front drive shaft and
requires a rubber nosed or some such attachment and this is where a
solid tube works better than a rubber/flex hose

GM GMT800 Grease Fitting Locations



1 - Drivers side, Upper ball joint
2 - Drivers side, Outer tie-rod end
3 - Drivers side, Lower ball joint




4 - Drivers side, Inner tie-rod end
5 - Drivers side, Pitman arm (at relay rod)




6 - Passengers side, Idler arm (at relay rod)
7 - Passengers side, Upper end of idler arm mount




Close up view of the 90 degree, 6mm, zerk that was replaced on the end of the idler arm, where it connects to the relay rod. With the factory straight zerk, it's next to impossible to get a grease gun fitting on it because of the AC compressor/mount that is above it. If you turn your wheels to the left side you can access the straight zerk.




6 - Passengers side, Idler arm (at relay rod) (Different view. Same as #6 above)
8 - Passengers side, Inner tie-rod end




9 - Passengers side, Lower ball joint
10 - Passengers side, Outer tie-rod end
11 - Passengers side, Upper ball joint

[jmaotto]

The most difficult one is what I call the eleventh fitting. Many people do not know it is there. It on the idler arm high up where it is attached to the frame.

[N-Trouble]

Even with a flex hose on my grease gun the inner three zerk fittings are tough to get at. 90* fitting makes it much easier...

[RCMAN46]

BenK wrote:
Change out the metal tube to a flex hose

Have NOT had one I could not get at

X2

Buy a quality flex hose that has a quality zerk fitting and it will stay on the zerk while pumping grease. The cheap ones do not grip the zerk very well.

[BenK]

Change out the metal tube to a flex hose

Have NOT had one I could not get at

[Bigfoot_affair]

It isn't that bad of a job....

[N-Trouble]

I have a 2012 and yes the inner three grease fitting are a bit tough to get to. I first picked up a set of the 90* zerks but found them to be a pain to point in the direction I wanted and also be snug. You have to shim them with small washers to get them to line up the way you want. I ditched them and picked up a 90* adapter for the grease gun. Problem solved and much simpler.

[Majja13]

I have what sport45 did. Love the 90 degree adapter on the grease gun

[fj12ryder]

Like Charles said the best thing to do is take one out, if you can, and shop for a replacement. There are usually 2 types of thread so you can't say for sure until you take the old one out.

Don't forget that there are press-in zerks too, these can be spotted by the fact there's no flats on the zerk, so no way to unscrew them. I wouldn't be surprised to see these as OEM.