NP205 speedo gear replacement - The 1947 - Present Chevrolet & GMC Truck Message Board Network

asphaltburner · 11-26-2008, 02:02 AM

After installing my twin-stick NP205 I find I have no speedometer function. T/case doesn't turn the cable. Not sure if this newly rebuilt t/case has a speedo gear (which would make sense).
Can anyone tell me,...will I find the speedometer gear within a "retainer" that the speedo cable screws onto? Any pics of the gear and retainer? Emailed stephen@offroaddesign, but I'm sure they're busy as hell with this economy! Thanks, Todd.

asphaltburner · 11-27-2008, 01:14 AM

Hello!
Anybody replaced a speedometer gear in an NP205? Todd.

Prong · 11-27-2008, 07:54 AM

IIRC, the cable should plug into an adapter, then into the T case. Lemme see if I can find that pic of the adapter...

Here you go: http://67-72chevytrucks.com/vboard/s...d.php?t=313774

Those gears inside should be all metal if I recall. I had to have the speedo shop regear mine after a mishap with my transfer case a few years ago.

*Edit* I see you're probably after the hard gear inside. The best thing I can tell you there is if the gear needs replaced, try to match the teeth count, or else you'll have to have the speedo recalibrated.

asphaltburner · 11-27-2008, 01:19 PM

Yo! Prong!
How do? And thanks! Happy Thanksgiving!
Mine does not have the right-angled part, but I believe that the coned piece that's pictured may be similar to what I do have. Mine has a hex collar for a wrench and must unscrew from the t/case. I still have the NP205 core from my donor flatbed, so I'll pull it today. It has a gear that was working, so I'll use it. I hope that's what the problem is,...haven't heard back from stephen@offroad design.com yet. But those guys are WAY busy, especially with the economic changes we're going through,...and the holiday sales season, I hope!!
Thanks again. I'll post a pic of the parts in question once I recover from last night and get back to work on FRANKENTRUCK. Todd.

worthirt_99 · 11-27-2008, 02:53 PM

I found all of my tranny parts and speedoparts here. You will have to look closely since they have all makes.

Transmssion and speedo parts

1-tonmudder · 11-27-2008, 03:16 PM

Quote:

Those gears inside should be all metal if I recall.

Yeah they will be up until about 1974-75,after that they splined the shaft and used a plastic gear.The pre 74ish 205's will not have splines that the speedo gears rides on,just has a metal gear and thrust washer.The gear is sandwiched between the bearing and thrust washer.

worthirt_99 · 11-27-2008, 03:24 PM

try here also
NP 205 stuff

asphaltburner · 11-27-2008, 04:37 PM

Yo! Y'all!
Recovered nicely now, pulled the gear and retainer from the donor flatbed's NP205 and here it is:

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Name: 112708 003 (Custom).jpg
Views: 11589
Size: 26.9 KB

Identical to the one in my ORD twin-stick NP205, and appears to be the same for the old FRANKENTRUCK NP203 (but it has the right-angled reduction gear attached in addition to this).
Thank you very much for the links and info, I hope this will also help someone in the future. You can also tell if you have a speedo gear in place by simply looking at the end of the retainer after removing the speedo cable. The end of the speedo gear fills the end of the retainer, otherwise there'd be an empty hole.
Happy Thanksgiving dudes!
Todd.
P.S. Found my speedometer to be faulty,...swapping for the donor flatbed's. Fuel gauge too (as it's now suspect since it doesn't work either) Thanks again.

asphaltburner · 11-28-2008, 01:21 PM

Yo!
Replaced the faulty '78 speedometer with the donor flatbed's '73,...worked great but the "H" stamped gear (18 teeth) made the speedo indicate that I was going 70 when I couldn't have been going but 55-60, so pulled the "J" stamped gear (19 teeth) from the donor flatbed's NP205 and that helped alot. I'll have to do some road testing to see how close it is now.
Still have a pegged fuel guage, so I'll start checking the wiring. New senders, and both guages indicate beyond full when the key is turned on (infinite resistance). Thanks again, Todd.

Prong · 11-28-2008, 07:39 PM

Your gauge problem is most likely a ground problem (lack of). Do your ground wires off the sender(s) have a good bite into clean steel on the frame?

asphaltburner · 11-29-2008, 01:36 AM

Yo! Prong!
Naw,...perfect grounds on the new senders, this is a sensor lead wiring problem,...the gauge is sensing infinite resistance instead of the 40 - 90 ohms that the sender would provide it.
I posted a FRANKENTRUCK update post,...check it out.
Thanks,...I'll get it tracked down soon.
You should PM me with where you're at in Colorado, I'd sure like to know! Todd.

11-26-2008, 02:02 AM	#1
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	NP205 speedo gear replacement After installing my twin-stick NP205 I find I have no speedometer function. T/case doesn't turn the cable. Not sure if this newly rebuilt t/case has a speedo gear (which would make sense). Can anyone tell me,...will I find the speedometer gear within a "retainer" that the speedo cable screws onto? Any pics of the gear and retainer? Emailed stephen@offroaddesign, but I'm sure they're busy as hell with this economy! Thanks, Todd.

11-27-2008, 01:14 AM	#2
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: NP205 speedo gear replacement Hello! Anybody replaced a speedometer gear in an NP205? Todd.

11-27-2008, 07:54 AM	#3
Prong Registered User Join Date: May 2007 Location: CO Posts: 475	Re: NP205 speedo gear replacement IIRC, the cable should plug into an adapter, then into the T case. Lemme see if I can find that pic of the adapter... Here you go: http://67-72chevytrucks.com/vboard/s...d.php?t=313774 Those gears inside should be all metal if I recall. I had to have the speedo shop regear mine after a mishap with my transfer case a few years ago. Edit I see you're probably after the hard gear inside. The best thing I can tell you there is if the gear needs replaced, try to match the teeth count, or else you'll have to have the speedo recalibrated. Last edited by Prong; 11-27-2008 at 08:05 AM.

11-27-2008, 01:19 PM	#4
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: NP205 speedo gear replacement Yo! Prong! How do? And thanks! Happy Thanksgiving! Mine does not have the right-angled part, but I believe that the coned piece that's pictured may be similar to what I do have. Mine has a hex collar for a wrench and must unscrew from the t/case. I still have the NP205 core from my donor flatbed, so I'll pull it today. It has a gear that was working, so I'll use it. I hope that's what the problem is,...haven't heard back from stephen@offroad design.com yet. But those guys are WAY busy, especially with the economic changes we're going through,...and the holiday sales season, I hope!! Thanks again. I'll post a pic of the parts in question once I recover from last night and get back to work on FRANKENTRUCK. Todd.

11-27-2008, 02:53 PM	#5
worthirt_99 Registered User Join Date: Jun 2008 Location: Moore, OK Posts: 41	Re: NP205 speedo gear replacement I found all of my tranny parts and speedoparts here. You will have to look closely since they have all makes. Transmssion and speedo parts

11-27-2008, 03:24 PM	#7
worthirt_99 Registered User Join Date: Jun 2008 Location: Moore, OK Posts: 41	Re: NP205 speedo gear replacement try here also NP 205 stuff

11-27-2008, 04:37 PM	#8
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: NP205 speedo gear replacement Yo! Y'all! Recovered nicely now, pulled the gear and retainer from the donor flatbed's NP205 and here it is: Identical to the one in my ORD twin-stick NP205, and appears to be the same for the old FRANKENTRUCK NP203 (but it has the right-angled reduction gear attached in addition to this). Thank you very much for the links and info, I hope this will also help someone in the future. You can also tell if you have a speedo gear in place by simply looking at the end of the retainer after removing the speedo cable. The end of the speedo gear fills the end of the retainer, otherwise there'd be an empty hole. Happy Thanksgiving dudes! Todd. P.S. Found my speedometer to be faulty,...swapping for the donor flatbed's. Fuel gauge too (as it's now suspect since it doesn't work either) Thanks again. Last edited by asphaltburner; 11-27-2008 at 04:39 PM.

11-28-2008, 01:21 PM	#9
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: NP205 speedo gear replacement Yo! Replaced the faulty '78 speedometer with the donor flatbed's '73,...worked great but the "H" stamped gear (18 teeth) made the speedo indicate that I was going 70 when I couldn't have been going but 55-60, so pulled the "J" stamped gear (19 teeth) from the donor flatbed's NP205 and that helped alot. I'll have to do some road testing to see how close it is now. Still have a pegged fuel guage, so I'll start checking the wiring. New senders, and both guages indicate beyond full when the key is turned on (infinite resistance). Thanks again, Todd.

11-28-2008, 07:39 PM	#10
Prong Registered User Join Date: May 2007 Location: CO Posts: 475	Re: NP205 speedo gear replacement Your gauge problem is most likely a ground problem (lack of). Do your ground wires off the sender(s) have a good bite into clean steel on the frame?

11-29-2008, 01:36 AM	#11
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: NP205 speedo gear replacement Yo! Prong! Naw,...perfect grounds on the new senders, this is a sensor lead wiring problem,...the gauge is sensing infinite resistance instead of the 40 - 90 ohms that the sender would provide it. I posted a FRANKENTRUCK update post,...check it out. Thanks,...I'll get it tracked down soon. You should PM me with where you're at in Colorado, I'd sure like to know! Todd.



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