Wet bolt zert fittings

[bigred715]

I want to replace my straight zert fittings with 45 degree fittings for easier attachment with grease gun. It takes a 5/16 wrench to get them out, but what is the size to buy as far as thread dimensions to get new ones?

[hickory]

I don't know the size offhand, but why not take one out and take it with you to the auto parts,hardware, or farm store?

[Tom S.]

quote:Originally posted by hickory

I don't know the size offhand, but why not take one out and take it with you to the auto parts,hardware, or farm store?

Agree, plus that way you can make sure the threads on the Zerks are the same thread (metric vs. SAE).

[Irlpguy]

I replaced mine with 45 deg ones and they were 1/8" pipe thread. I believe the metric ones still use pipe thread, the difference is the wrench size to install/remove them and the other measurements for height and so on.

[jcurtis934]

What I used to replace the missing ones on my monty said 1/4 inch on the box. John

[Irlpguy]

quote:Originally posted by jcurtis934

What I used to replace the missing ones on my monty said 1/4 inch on the box. John

John here is a picture of a 1/8" npt on the left and a 1/4" on the right, I don't think they drill that size hole in the bolt. I would say the box was marked wrong. I also just went and checked on mine and they are definitely 1/8".

[WaltBennett]

I put in the Mor/Ryde kit and they were 1/8".

[Overlord]

I installed my wet bolts with the zerk fittings towards the center of the trailer, not on the tire side. Makes it much simpler to grease them up, so long as you able to crawl under the rig, and it gives you an opportunity to check out other things while you are under there, like the u-bolt torque, inner sidewalls of the tires, etc.

The 1/8" NPT designation of the thread size refers to the diameter of the hole that goes through the threads, not the threads themselves.

[woodtic]

quote:Originally posted by Overlord


The 1/8" NPT designation of the thread size refers to the diameter of the hole that goes through the threads, not the threads themselves.

Not quite. 1\8" NPT is a standard threading designation just as is 1\2" NC (1\2-13). You are correct that1/8" is the reference to pipe inner diameter, which can actually vary significantly with the schedule(wall thickness) of the pipe.

[bigred715]

Thank you for all the replies. I think to be safe I will take one out and go to auto parts store and get the right ones. My zerts face the inside of trailer and will get 45 degree fittings to make it easier attaching grease gun. Wet bolt system was put on by factory when in Indiana.

[astrungis]

I bought a right angle grease gun fitting for the tip @ $4 in AutoZone. Works well.

[jcurtis934]

Irplguy, I can believe the box was incorrectly marked. Will have to go out in the morning sometime when the temperature is low enough that I feel like crawling under the monty to recheck some of the ones that were already there. Too hot and humid now...florida at it finest. John

[shovelhead86]

Since there seems to be a discussion of size. NPT stnds for notional pipe thread. It is the size of the hole in the pipe. The od of the threaded part is about 1/4 in larger to accommodate the wall thickness of the pipe. Maybe a little less but not much.

[bigred715]

Went to local auto parts store and bought some 45 degree zerts. They were1/4 x 28. Some went in easy and others were a battle. Not a very good job tapping the holes by Mor/ryde. Got them installed for about $16 and will be putting the grease to them tomorrow.

[Irlpguy]

quote:Originally posted by jcurtis934

Irplguy, I can believe the box was incorrectly marked. Will have to go out in the morning sometime when the temperature is low enough that I feel like crawling under the monty to recheck some of the ones that were already there. Too hot and humid now...florida at it finest. John

John after doing some research and talking with MOR/ryde "again" I reckon the fittings you used were indeed 1/4 - 28. They are of course not NPT and the 28 is the number of threads per inch and are what MOR/ryde uses in their "wet bolts".

The picture I posted in an earlier post and here again, shows a 1/4 - 28 on the left (the smaller of the two) and the one on the left is in fact a 1/8" NPT fitting (not 1/4" NPT as I previously stated). It has 27 threads per inch but is much larger than the 1/4 -28.



I apologize if I added further confusion to what zerk is used, we just need to understand the 1/4 - 28 is almost exactly the same as a 1/4" fine thread bolt and is the one used.

A 1/8" NPT zert has 27 threads per inch but is too large for this application.

A 1/4" NPT zert has only 17 threads per inch and is much too large to be used in this application.