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Re: Suspension Parts List

Posted: 11 Feb 2017, 20:52
by Def
Those M16 tube adapters look to be LH thread. I believe you'd want this to adapt to the Moog balljoint (mine looks RH thread on inspection, and it makes sense, given I've never seen a LH threaded tie rod). ... results=13

That said, an M16x1.5 mm RH tap and some 1" OD x 0.25" WT DOM tubing would get you a suitable bung. You don't necessarily need the OD machined down in the middle of the threaded section. The only benefit I could see would be slightly reduced bending stress at the weld, and it needing to be a well prepped butt weld (nothing out of the question given you're building an entire chassis with primarily butt welds!).

Also, your rear outer toe rod ends being 5/8" bore and 1/2" shank - I believe you've got that backwards. The P/N you're listing is going to a 1/2" bore, 5/8" shank. Typically bore/shank "mismatches" in rod ends are going to upsize the shank, not downsize. You were probably trying to keep a 1/2" tube bung on that arm, but I don't think that rod end exists. Plus I think it's best to keep the bore and shank the same, which generally makes it easier to get replacements since the volume is magnitudes higher on those sizes. Plus, as I mentioned, you can only upsize the shank, so in our case it's going to end up with some monster shanks for the usage like 3/4".

On the subject of tube bungs/adapters - I'd maybe group them by what size tubing they're interfacing with. I also looked at a few McGill parts you've got linked, and I don't think they'll work in some of the locations, like most/all of the front suspension (1" x 0.083" book tubing size I believe). I think it's worthwhile pointing out what tubing you're intending all those bungs to adapt to, especially if it's not a book size. Keep in mind that there are 3 things you've got to control on the tube bungs - internal thread size, internal thread direction, tube size it mates to as a slip fit. Any one of the three that's out and you've got a piece that's probably going to take more time modifying than making one from scratch!

Re: Suspension Parts List

Posted: 11 Feb 2017, 20:58
by Def
These guys look to have a wide variety:

Re: Suspension Parts List

Posted: 11 Feb 2017, 21:04
by Def
And of course MWC has them as well:

Re: Suspension Parts List

Posted: 12 Feb 2017, 13:22
by steveo
Yeah, the sheet even says they should be a RH thread and then I linked to the left hand thread. That needs correcting.

Sure, they wouldn't be too hard to make, just trying to make decision about what I'm prepared to fab and what I'm not. These are borderline, but if they're out there for a fair price then I'd rather buy.

They should all be 1/2" bore and 5/8" shank, so that's an error in the table. I think it's linking to the right part though.

I think I'm getting confused by the bores on the bungs.


The specs say 1"x0.0625" for the BUN8R. As you say, the book specifies 1" x 0.083" tube, so the internal diameter of a 1x0.083 tube is 0.834" which as you say won't fit the specified tube.

What am I missing here? The BUN10 clearly doesn't fit. I was under the impression a number of folks had already used these hence why I didn't detail check the specs there as I assumed (ooops!) they would be OK.

No intent to change the planned book tube sizes. I am now structural engineer and wouldn't even think about doing that as I am nowhere near competent to do so.

OK folks! Who used what bungs on what tubes so far????

I'll check further tomorrow. I've just flown almost half way round the planet so may be a little punchy right now. We'll take another look after some sleep!

Re: Suspension Parts List

Posted: 12 Feb 2017, 13:35
by steveo
An exhaustive list of all of Mid-West's Imperial bungs: ... hTerm=bung

Now that's a lot of variety in bugs, so we're after the one where the diameter of the insert part (d2 in the McGill Drawing) is less than 0.834" (1" - ( 2 x 0.083") which gives us:

I think that's right yeah? And indeed their specs say so:

Part Number System Thread A B C D E F G Fits Tube OD Fits Tube Wall
WTF-8R-0.819 Inch 1/2-20 RH 0.819 1.0000 0.6250 0.7150 0.060 0.7500 2.0000 1.0000 0.0830

So weird that the McGill ones don't fit. Ah well! I'll update the list tomorrow!

Re: Suspension Parts List

Posted: 12 Feb 2017, 18:54
by Def
It seems like I'm 50/50 on having stuff work by trusting the internets. Sometimes it works out, other times you get a "well, I dunno" on the other end. :)

The outer lower toe rod ends/bearings all need to be 5/8" bore, just reiterating that detail in case I wasn't clear before.

Re: Suspension Parts List

Posted: 13 Feb 2017, 02:43
by steveo
OK, awake at 02:30 local time thanks to the wonder of jet lag.... :shock:

So went through a few things:

a. Changed the numbering referencing format so that it's easier to relate joints, tubes and locations
b. Changed the table format so that joints and their bungs/cups are on the same line therefore they directly reference each other
c. Added the tube OD, wall and ID so that the bungs can cross-ref these
d. Reformatted the data so it's more consistent for pivot tables
e. Came up with a pivot table that allows you to cross-ref each item against the other parts on the same arm and the tube sizes
f. Checked the snot out of everything! (but I bet there's still errors)

See what y'all think:

Re: Suspension Parts List

Posted: 13 Feb 2017, 13:19
by Def
I don't see arms E and F (front tie rod?) shown on your diagram/figure, but if it's actually the tie rod, you'd only need one rod end there if you do an outboard rod end vs. stock outer tie rod. Be careful with lack of brake rotor clearance and lack of rod end articulation as well.

It's shaping up though!

Re: Suspension Parts List

Posted: 13 Feb 2017, 13:57
by steveo
Yeah I haven't modeled those yet. I do think there should be two rod ends though as there would be the that connects to the lower a-arm and at the other end another that connects to the rocker arm
Itself right?

The picture is clearing for my order now though. Basically rod ends fromMcGill and bungs/cups from MWC. Impressed with their range of bungs. They do have bungs for 1"x0.083" wall that have a 5/8" thread allowing to use *ahem* bigger balls if you want something a bit tougher :shock:

Re: Suspension Parts List

Posted: 13 Feb 2017, 15:22
by Def
Oh, is that for the push rod? That's separate from the tie rod, which controls steering.

Any particular reason 0.065" is used there? Seems kinda low to save maybe an ounce. I'll do a buckling calf, maybe share a buckling spreadsheet tomorrow.