M38A1/M170 Instrument (dash) Panel Screw Size?

brachus12 · Post by **brachus12** » Sun Nov 01, 2015 5:43 pm

Manual seems to call for a 2-5/8 hex hd screw for this? That seems absurdly long and does not match what we pulled off the M170. Is there a more updated screw for a 1962 M170?

brachus12 · Post by **brachus12** » Sun Nov 01, 2015 5:53 pm

Manual says "1/4-20 NC - 2 x 5/8" ... so does that mean 2-5/8" or something else? like grade 2, 5/8" length?

4x4M38 · Post by **4x4M38** » Sun Nov 01, 2015 6:21 pm

1/4-20 NC is 1/4-20 National Coarse thread, the 2 should be
the grade, 5/8" long as you suggest.

Take a look at another bolt or screw spec that you are familiar
with and you'll confirm.

Post by **wesk** » Sun Nov 01, 2015 7:35 pm

The -2 is not the grade. It is the tolerance in thread pitch fit. The bolt itself is 5/8" long.

4x4M38 · Post by **4x4M38** » Sun Nov 01, 2015 8:56 pm

Thanks for clarifying Wes.

BullRun · Post by **BullRun** » Sun Nov 01, 2015 10:53 pm

Dzus (pronounced Zeus) quarter turn fasteners (supplied by Shakespeare Products Company, probably a distributer) are used in the 0607 Plate (gauges)and SEM's (current trade name) fasteners are used in the 1804 Body Panel (dash).

The language in the parts manual is overlapping and interchanged for these parts too.

Your looking for the SEM's fasteners which are of a very specific design unique to SEM's fasteners.

4x4M38 · Post by **4x4M38** » Sun Nov 01, 2015 11:56 pm

You know, I was wondering about that. I was under the impression
the gauge panel on the M38 and M38A1 were nearly identical
and shared the same Dzus mounting fasteners.

The M170 must be different...

keats · Post by **keats** » Mon Nov 02, 2015 12:14 am

the m170 dash panel is different in several ways but still uses the same fasteners used on the m38 and A1 for attachment to dash.

brachus12 · Post by **brachus12** » Mon Nov 02, 2015 8:52 am

BullRun wrote:Dzus (pronounced Zeus) fasteners and SEM's fasteners are the trade names for the dash fasteners.

I'm talking about the main dash panel that goes the entire width of the Jeep and is held in place with 11 bolts, not the small gage panel with those special fasteners.

4x4M38 · Post by **4x4M38** » Mon Nov 02, 2015 9:11 am

Hah!

Lucky you. My M38 dash is held on with spot welds...

Post by **wesk** » Mon Nov 02, 2015 9:44 am

The little panel is properly referred to as the Custer, Instrument ( or Instrument Cluster) and the four fasteners factory installed were Shakeproof by name as shown in the Parts Manual Group 0607. Dzus and Sem show up later as these hardware companies gobbled each other up.

The full width panel is properly referred to as the Panel, Instrument Assy (or Instrument Panel). It is fastened with 11 screws as was the custom to call them during the 40's / 50's but which we more commonly refer to today as bolts.

We've managed to misinterpret and string Brachus12's post out quite a bit. Although Brachus12 was a wee bit vague in his post it was clear to me he was not trying to thread a bolt into a Shakeproof fastener receptacle and his subject title:

M38A1/M170 Instrument (dash) Panel Screw Size?

was clearly about the panel and not the cluster.

We are all anxious to help fellow members out but we are also obligated to take a moment to carefully read their question and then offer a well thought out answer which we hope will do it's job and answer the question CORRECTLY and not inject confusion into the topic.

If the question is not clear to you then ask for some clarification so you do not un-intentionally give the incorrect answer.

Granted this is a minor issue here but had the question concerned Fuel, steering or brake systems a wrong answer can send a hobbyist out to his shop for his last trip. None of us wants to be responsible for a fellow member's injury/death or loss of their project. Just try to use these steps when helping with information:

1-Carefully read the question.
2-If the question is vague/unclear then ask for clarification first.
3-Think out and verify the accuracy of your answer.
4-Then offer the answer.

BullRun · Post by **BullRun** » Mon Nov 02, 2015 3:36 pm

You can find what you want from just about any vender as NOS.

Those vehicles were built similar to the early 1960's USMC M38A1's. Unless you can find a 1960's M170 parts manual, the only way to come close to verifying the correct part specifications is to find the 1960's USMC M38A1 parts manual that lists part variations used at that time in manufacture. It is not encyclopedic in scope.

These later vehicles have many minor detail differences from the earlier M38A1 production that "might" be undocumented in the literature. If not listed in the USMC manual as a variation, in my experience with M38A1's the part would be the same as the earlier 1950's production. Keep in mind many parts especially small parts like fasteners have been superceded with later versions.

My 1956 parts manual lists the screw size as 1/4"-20NC-2-5/8th"

Portrayal Press carries reproduction manuals.

Post by **wesk** » Tue Nov 03, 2015 1:03 am

We carry the manuals in PDF format on our downloads page right here.

The Sep. 1956 ORD 9 SNLG-758 parts manual covers both the M38A1 and the M170 parts common to both jeeps up thru 56.

There is no M170 only parts manual.

To date no one has produced a copy of any USMC published M38A1 or M170 Parts Manual.

Here are the 3 primary M38A1/M38A1C/M170 Parts Manuals:

1956 ORD 9 SNL G-758. This is the most detailed manual available. 450 pages. This manual list all parts for cluster (Stud 7526590, Washer 7526591, & receptacle 7539255) attachment to dash and dash panel attachment to cowl.

1966 TM 9-2320-208-20P Organizational M38A1/M38A1C/M170 Parts Manual. This has very little detail. Has 143 pages. It has no partls listing for the full width instrument panel. It does list the gauges but not the cluster assy however it does list the stud retaining washer 7526591 and receptacle 7539255 for the gauge cluster. There is also a 1959 edition of this manual.

1966 TM 9-2320-208-34P Direct Support & General Support M38A1/M38A1C/M170 Parts Manual. This manual also has very little detail. It has 180 pages. It has no parts listings for the instrument cluster mounting hardware or the full width dash panel.

So the latest and earliest parts manuals show the same Quarter turn fastener setup for the instrument cluster attachment to the dash panel for the M38A1/M38A1C/M170 thru 1966 at least. The lack of any references or illustrations of the dash panel to the cowl installations in the later manuals indicate there was no change from the earlier manuals.

BullRun · Post by **BullRun** » Tue Nov 03, 2015 7:50 am

Although rare, there is a parts manual for the 1960's USMC M38A1 vehicles published not by the Army but by the Marines in 1966.

It is not comprehensive.

I have never seen any M170 manuals from the 1960's.

Post by **wesk** » Tue Nov 03, 2015 11:31 am

I would guess the USMC M38A1 manual you are referring to is the one used at their Barstow and Albany depots to rebuild older A1's to the same spec as the 60 to 64 contract USMC A1's. Their brevity can be attributed to their purpose being to identify changes to be made.

The primary use by the Marines for the M170 was as a radio jeep. Most well known as the MRC-87.

You are looking at two M170 manuals above.

The manuals can be downloaded here:
https://0hobaq-bn1305.files.1drv.com/y3 ... pdf?psid=1

https://0hobaq-bn1305.files.1drv.com/y3 ... pdf?psid=1