Speedometer issues

1950 - 1968, M38, M38A1, M170, modifications, sugestions, and ideas, official MWO's and unofficial field mods.
wardo74
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Speedometer issues

Post by wardo74 » Thu Nov 01, 2012 12:47 pm

So I'm looking at replacing my speedometer as the lens is cracked and it bounces around. My mechanic said that I could lubricate the speedometer cable, and that may solve the problem. Any ideas? If that works would it be possible to just replace the lens on my speedometer?

Thanks
First Love (& car): 1957 Willys CJ5
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Re: Speedometer issues

Post by Joe Gopan » Thu Nov 01, 2012 1:58 pm

Or you could buy a nice clean used OEM AC or SW speedometer removed from Salvage M-38A1 Jeeps that have never seen civilian use.
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Re: Speedometer issues

Post by artificer » Thu Nov 01, 2012 3:01 pm

Your mechanic knows what he is talking about & is not the usual parts changer type, we see here often.
Of course you can get a glass or one cut [inexpensively] if you like.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

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Re: Speedometer issues

Post by wardo74 » Thu Nov 01, 2012 8:35 pm

Yes, he is good. The speedo unit itself does not make any noise so I am inclined to try and oil the cable as I am wanting to save every penny I can for more important stuff like, new tires, 12V gauges, a whole new steering assembly because some redneck put in a power steering assembly!
First Love (& car): 1957 Willys CJ5
1999 graduate Vehicle Research Institute. Western Washington University
Current Project: 1952 M38A1 Ser # MD 26799

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Re: Speedometer issues

Post by Marty, SoCal » Fri Nov 02, 2012 11:07 am

Thin grease will work better than plain oil. If you have some engine assembly grease, Lubriplate, or CV joint grease in your shop, that will work well. Disconnect the cable from the back of the speedo, pull out the center core, pack grease into the opening of the sheath, insert the cable and twirl it around in the grease as you feed it back in, as the grease in the end of the sheath gets used up, add more, until the cable is all the way back in. You will have to rotate it a bit to get it to fully seat back into the drive gear mounted in the t-case.

Hope this helps!
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Re: Speedometer issues

Post by Joe Gopan » Fri Nov 02, 2012 1:30 pm

Try not to pack grease more than 2/3 of the length as too much will work up to the Speedometer Head and make a mess.
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HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
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Re: Speedometer issues

Post by wardo74 » Fri Nov 16, 2012 3:00 pm

Thanks guys,

I will try that in the next couple of weeks & let you know how I make out.
First Love (& car): 1957 Willys CJ5
1999 graduate Vehicle Research Institute. Western Washington University
Current Project: 1952 M38A1 Ser # MD 26799

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Re: Speedometer issues

Post by Joe Gopan » Sat Nov 17, 2012 3:52 am

Not all mechanics are speedometer technicians, and not all speedometers respond to lubing the cable or tinkering.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: Speedometer issues

Post by wardo74 » Tue Nov 27, 2012 1:46 pm

So i pulled the inner speedo cable out today, and put a small amount of engine grease on the cable, but as I was feeding it back in it got stuck 2/3 of the way back in. I backed it out and rotated the cable back in but it still hung up. After spending almost 10 minutes of trying to feed it back through I ran out of time. Tomorrow I will try inserting it from the tranny side instead of the speedo side as I think its' getting stuck on a sharp turn in the cable close to the transmission. If that doesn't work, I might just buy a whole new inner cable. The outer cable looks in great shape with no deterioration.
First Love (& car): 1957 Willys CJ5
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Current Project: 1952 M38A1 Ser # MD 26799

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Re: Speedometer issues

Post by Joe Gopan » Tue Nov 27, 2012 2:39 pm

It only goes in in one way, from the Dashboard end, the original has a groove with a retainer clip at the blade end where it attaches to the transfer case, the clip has to be removed before it can be pulled out.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
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Re: Speedometer issues

Post by artificer » Tue Nov 27, 2012 3:54 pm

Joel wrote:It only goes in in one way, from the Dashboard end, the original has a groove with a retainer clip at the blade end where it attaches to the transfer case, the clip has to be removed before it can be pulled out.
Even so....the inner speedo cable [was pulled] out today.
Both the inner & outer cable are wound materials.
Be sure the cable doesn't have one of the wound wires broken over any of it's length.
If it doesn't, but hangs up half way through the outer cable....the outer cable is bad & should be replaced [best as a pair].
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

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Re: Speedometer issues

Post by wardo74 » Tue Nov 27, 2012 4:23 pm

I'll take a look at it again tomorrow, I probably will end up getting a new outer & inner shaft.

Incidently I just referenced Page 224 of my TM 98014 manual. According to what I read it has you basically use long nose pliers and pull out the inner core, and didn't mention any kind of a clip in the shaft attaching to the transmission.....I also noticed part of my transfer case seal hanging out of the transfer case. Good thing I have an extra transfer case, cause that one may be toast now :(
First Love (& car): 1957 Willys CJ5
1999 graduate Vehicle Research Institute. Western Washington University
Current Project: 1952 M38A1 Ser # MD 26799

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Re: Speedometer issues

Post by Joe Gopan » Tue Nov 27, 2012 4:39 pm

The M-38A1 cables do have a retainer clip at the drive end. (C-Clip)
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

wardo74
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Re: Speedometer issues

Post by wardo74 » Tue Nov 27, 2012 6:49 pm

Ben Dover wrote:The M-38A1 cables do have a retainer clip at the drive end. (C-Clip)

I believe you. I hope I did't screw up the clip when I pulled the speedometer cable out of the Tranny. It took awhile and then it finally popped out. Hopefully it's not stuck in the outer cable. Ugh!!
First Love (& car): 1957 Willys CJ5
1999 graduate Vehicle Research Institute. Western Washington University
Current Project: 1952 M38A1 Ser # MD 26799

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Re: Speedometer issues

Post by wardo74 » Sat Dec 01, 2012 9:42 pm

So I pulled out the outer cable assembly and sure enough there was a hole through the rubber, but not all the way though to the inner shaft. I think the metallic braiding was damaged and pinched the inner cable. I know your supposed to change them both at the same time, but I'm going to replace the outer cable. Hopefully it didn't fatigue the inner cable enough to wear it will shear in the future, but given the option of spending $25 or $100, I'll choose the former. Also I didn't see any deformation of the inner cable.
First Love (& car): 1957 Willys CJ5
1999 graduate Vehicle Research Institute. Western Washington University
Current Project: 1952 M38A1 Ser # MD 26799


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