Steering Knuckle inspection port thread

Joined
May 27, 2017
Messages
18
Location
Australia
Hi
Does anyone know the thread of the plug that goes into the steering knuckle inspection port on a HZJ80/HZJ105 ?
It is P/N 90345-53020.

Also I gather it is a tapered thread...

I am looking to replace it with a Relief Pressure Grease Fitting to prevent overfilling of the hub when you regrease using a greaseable CV joint. There is at lease one cv joint kit I have seen that includes the fitting.. but I would prefer to get my CV from a different supplier .,..
 
Joined
Oct 6, 2018
Messages
69
Location
Kansas City
I know the Nitro Birfields have the zerk fitting, but I am also pretty sure that the RCV units do as well. I would trust RCV over anything else if you desire the strength, as the company builds the best C/V joints in the business and have run their custom stuff behind a few crawlers with zero issue. The only thing is would recommend if you run these high strength Birfs is that you go part time 4WD if you haven't already. There are a bunch of threads shoing the reasons why as most of the Chromoly Birfs have a very short life in the full time 4WD trucks.

I am running the Wits end ABS plugs with the grease zerk fitting on them. They make for a super easy way to keep up on maintenance for the knuckles as you unscrew the fill port plug to relief pressure from the greasing, as well as aid in being able to check fluid level while greasing.
 
Joined
Dec 10, 2007
Messages
8,669
Should be British Standard Pipe Taper (BSPT) 3/8"-19 TPI, but double check that.

Gearing Dynamics in your neck of the woods sells the correct PRV. I recall looking for another source years ago, didn't have much luck IIRC.

One option might be to tap the stock knuckle grease plug for a more common PRV size/thread type.

FWIW, I have greaseable CV joints in one of my 80 series and IME they don't need much make-up grease as long as the seals aren't leaking. Are you doing frequent deep water crossings??

Have you done the axle housing breather bypass mod??

Wait for others to chime in.

Chart of BSPT Thread sizes with definitions:

 
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Joined
May 27, 2017
Messages
18
Location
Australia
Good suggestion with Gearing Dynamics.. they are only about an hours drive from home :) I will lookup the axle housing breather mod.. I only run a standard breather setup ..
 
Joined
Dec 10, 2007
Messages
8,669
The breather mod is just bypassing the factory breather with a section of rubber fuel hose running up to the engine bay, zip tie it off somewhere (I use the coil bracket) and stuff a small filter in the end. I also put one loop of tubing (360' turn) in mine at the upper end. You'll want to leave some slack in the line for axle movement.

Some people have drilled out (opened up) the ID of the factory pipe that screws into the axle housing as the factory pipe tends to get clogged with grease. One person recently tapped the axle housing for an even larger pipe.
 
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Joined
May 27, 2017
Messages
18
Location
Australia
Managed to get some from here (CMS) Actually the workshop that does maintenance on my cruiser.. I just had to ask :). It is a 'cruiser specialist workshop that mostly specialises in Troop carriers.. but also has excellent knowledge of other 'cruisers. Is also a terrain tamer dealer and the valves are a terrain tamer part .. Terrain Tamer include them in some of their greaseable birf kits. Also suggested to use them if you use there spindle bearing greaser to avoid over filling the swivel housing .

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