Jam nuts for SE adjustable push rods ???
Road Master
Joined: Jul 2006
Posts: 886
Likes: 4
From: Virginia
SE Tapered Adjustable Pushrods. When I was chasing valvetrain noise, I replaced lifter manufacturers and I varied pushrod lengths a number of times and ended up snapping one of the nuts in two while tightening. It broke straight across two points. The nuts are very hard, brittle etc. From repeated tightening, I think I fatigued them to the point one broke.
The nuts are undersized from a standard 3/8-24UNF nut. Standard is 9/16" hex, these are 1/2" hex. What I did was to take some grade 5, 5/16-18UNC nuts, drilled them out and tapped them to 3/8-24UNF to replace all 4 SE nuts.
The nuts are undersized from a standard 3/8-24UNF nut. Standard is 9/16" hex, these are 1/2" hex. What I did was to take some grade 5, 5/16-18UNC nuts, drilled them out and tapped them to 3/8-24UNF to replace all 4 SE nuts.
Road Warrior
Joined: Sep 2008
Posts: 1,465
Likes: 16
From: Nor Cal
I don't remember where, but someone has said that all the SE pushrods that have the manufacturing date around 2011, have a better, thicker lock nuts, and mine (original) are appeared robust enough that I don't think they will break. 1000 miles after the installation, and still running smoothly.
Road Master
Joined: Mar 2011
Posts: 988
Likes: 1
From: Ashevegas
I had one of the nuts in the tapered set break during a cam install a couple weeks ago (PITA). I don't know what the manufacturing date was because I have since trashed the packaging. I replaced with a new set from the dealer, and all seems good so far.
HDF Community Team
Joined: Jun 2006
Posts: 12,776
Likes: 2,607
From: san antonio
It happens I'm sure, I just think its magnified on the Internet and made out to be a bigger problem than it really is. I think a lot of times they are over tightened. I've seen one break during an installation and it was because the guy was really cranking down on it to tighten the jam nut which is totally unnecessary.
It is my understanding that the problem was acknowledged and addressed but I don't know when or how. Having been burned, I still won't use the nuts but I like the pushrods.
Originally Posted by HogYild
The nuts are undersized from a standard 3/8-24UNF nut. Standard is 9/16" hex, these are 1/2" hex. What I did was to take some grade 5, 5/16-18UNC nuts, drilled them out and tapped them to 3/8-24UNF to replace all 4 SE nuts.
Last edited by djl; Feb 17, 2012 at 11:09 AM.
Ultimate HDF Member
Joined: Jan 2008
Posts: 6,532
Likes: 132
From: SoCal
FYI, the SE Tapered Quick Install pushrod sets were first available in 2008. I bought my first set in March 2008. I had adjusted enough pushrods by then to know what I was doing. The problem with the adjustor nuts was a quality issue; the metal was brittle and porous. Some would crack from the inside under normal tightening pressure but unless they were over tightened, the nut would not break and you could not see the crack from the outside. Of course, under heat, they would expand enough to "unthread" and the pushrod would collapse. This is what I observed and it happened to me twice; first time I was close to home and limped back but the second time, it happened so fast all I could do was shut down before major engine damage occurred from the loss of oil pressure when the lifter retaining clip hit the oil pump. I never had a nut actually break while tightening but apparently more than a few did break them while tightening. If they are going to come loose, they will come loose in less than 20 miles of riding; at least that was my experience.
It is my understanding that the problem was acknowledged and addressed but I don't know when or how. Having been burned, I still won't use the nuts but I like the pushrods.
This fix will work. The nuts that Poorboy machines are G8 3/8-24UNF nuts that have been machined to the 1/2" diameter.
It is my understanding that the problem was acknowledged and addressed but I don't know when or how. Having been burned, I still won't use the nuts but I like the pushrods.
This fix will work. The nuts that Poorboy machines are G8 3/8-24UNF nuts that have been machined to the 1/2" diameter.
HDF Community Team
Joined: Jun 2006
Posts: 12,776
Likes: 2,607
From: san antonio
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Intermediate
Joined: Aug 2009
Posts: 28
Likes: 0
From: West Seneca New York
Thanks for all the info! Not sure yet, after reading these comments what I will do. I was thinking about reusing the stock ones. Not much more work and save a few bucks to boot. Now that spring is in the air I'm thinking the faster I get it done the better. I am getting the itch to see what the ride will be like. Andrews 48H cam, Khrome Werks 3 1/2 inch slip ons and Thunder max ECM.Thanks again ...
