Tailwheel grease zerk fitting size?

[Kooshball]

Does anyone here know what size zerk I would need to replace the zerk on an RV4 tailwheel assembly (pictured)? I need to replace the one shown as it has stopped accepting grease.

Thx!

 

[Sam Buchanan]

Forget the grease fittings, they are practically useless. The bearings in the wheel are shielded and don't accept grease. If the bearings get noisy they can be inexpensively replaced.

The yoke needs to be disassembled (easy to do) for proper cleaning and maintenance. While it is apart, clean thoroughly, inspect the locking pawl and spring, and grease prior to reassembly. Your tailwheel will thank you.

 

[rv6n6r]

LPS-2

Lots of threads on this but after 24 yrs trying different grease and oil regimes on the swivel mechanism, what works best for me is LPS-2. Specifically, coat the shaft and bushing at annual, then a squirt past the top washer every few months seems to keep it from drying out or gumming up longer than other methods.

Also I'm now sporting one of those lightweight tailwheels after many years with the standard one. Expensive but nice, and the bearings seem a lot more robust.

 

[Sam Buchanan]

I was gifted one of those fancy tailwheels, looks great and the lighter weight is a good thing since I recently replaced the 0.016" rudder with the 0.020" version. But it is considerably noisier on our grooved runway than the old Vans tailwheel and is more prone to track irregularities in the pavement.

 

[Kooshball]

Thx folks! Disassembly / clean / lube is in order as it just started requiring more force than usual get it to break out and swivel (seems normal when I lift the tail and move it around). Based on this thread I won’t waste any time on replacing the zerk though.

Thx!

 

[RV6_flyer]

Does anyone here know what size zerk I would need to replace the zerk on an RV4 tailwheel assembly (pictured)? I need to replace the one shown as it has stopped accepting grease.

Thx!

The Zerk fitting is the same as what is used on automobiles.

More info here.

Below is Copy/Paste from my notes:


Zerk fittings

¼” – 28 Taper thread
¼” – 28 Straight Thread hole but taper on the fittings

1/16” NPT

PTF and NPTF (Dryseal) threads are compatible with NPT threads. UNF and UNEF threads are similar to threads on a machine screw or bolt. They require a sealant, such as an O-ring, to minimize leakage. SAE-LT threads are tapered but designed to be installed into a 1/4"-28 straight-thread UNF hole.

Drill Size for ¼ – 28 tap = #3 or 7/32” 7/32=0.21875 #3=0.213


Drill hole #3
Tap 1/4-28
Insert Zerk

 

[andoman]

what works best for me is LPS-2. Specifically, coat the shaft and bushing at annual, then a squirt past the top washer every few months seems to keep it from drying out

+1!!! Easiest most reliable tailwheel maintenance method, IMHO.

I, too, have the jarring lightweight tailwheel. Every time I fly my -4 I swear I’ll throw the old heavy tailwheel back on. Haven’t done it after 2 years. I guess I’m getting used to my molars aching. Haven’t decided if the pain is from the tailwheel clunking or from the angry teeth grinding at each chunk…

 

[gnuse]

Amazing that there is still the thought that the Zerk fitting on the tailwheel stem is used as a grease fitting.

It is there to locate the bushing in the stem.

 

[Kooshball]

Amazing that there is still the thought that the Zerk fitting on the tailwheel stem is used as a grease fitting.

It is there to locate the bushing in the stem.

Seems like a strange thing to use as a locator…can’t fault folks for thinking it is there to accept grease.