NP 205 and speedo gears - The 1947 - Present Chevrolet & GMC Truck Message Board Network

utvaquero59 · 10-18-2007, 01:52 PM

OK, I've been searching for the last 1/2 hour with little success. I've got a '71 4x4 w/NP205 t-case and I'd like to get my speedo working again. I've got a new cable on the way and wanted to replace the drive and driven gears with the appropriate ones to get my speedo accurate. I called a couple places and one told me I needed an 8-tooth drive gear and a 20-tooth driven gear for a TH-350/NP205 combo, 4.10:1 gears, and 31 5/8" nominal tire height 33x12.50 R16.5's.

So, assuming he's correct--WHERE THE CRAP can I find such gears? Everything I've found that's the right tooth count is for TH-350 trannies but nobody can tell me if those gears fit in the t-case. My guess is they don't so can you guys help me out here?

72Cheyenne454 · 10-18-2007, 02:19 PM

Try Quad 4x4. They specialize in NP205 parts. I know I've seen speedo gears on their website.

www.quad4x4.com
1-406-446-2427

utvaquero59 · 10-18-2007, 02:40 PM

72Cheyenne,
Thanks, they've got a drive gear available (7 tooth) assuming mine's plastic--can anybody confirm whether '71's had plastic or metal drive gears? The only thing left to decide, assuming the plastic gear works in my t-case, is where to find an 18 tooth driven gear. These fit into the base of the speedo cable, right? It's been a long time since I messed with speedo gears and cables. But, if it does, I just replace whatever gear is there with an 18-tooth gear that fits and I think I should be in business.

utvaquero59 · 10-19-2007, 01:32 PM

So, a little more digging shows me that "early," NP205s had steel drive gears, "late," NP205's had plastic ones but no clear definition of what years comprise "early," and "late," t-cases. Any more help?

Yes, I know, climb under the truck, pull the speedo cable and look. Arghh!

bdozeraz · 10-19-2007, 02:29 PM

I haven't seen any different speedo gears for the 205. I took mine to a local speedo calibration place and they made an adapter that hooked to the speedo output on the 205 and the cable hooked to it. It cost around a hundred bucks for the whole deal. It seemed a little pricey for what took them about 10 min, but my speedo is correct now.

utvaquero59 · 10-19-2007, 08:02 PM

OK so I got up under there today to discover steel drive and driven gears, 5 tooth count on the drive gear and 19-tooth count on the driven gear. I also have a question for those more knowledgable than me: what's the proper lube for the 205? One source said Dexron II, another said GL-5 or its Mil-spec equivalent.

10-18-2007, 01:52 PM	#1
utvaquero59 Registered User Join Date: Aug 2007 Location: St. George, UT Posts: 70	NP 205 and speedo gears OK, I've been searching for the last 1/2 hour with little success. I've got a '71 4x4 w/NP205 t-case and I'd like to get my speedo working again. I've got a new cable on the way and wanted to replace the drive and driven gears with the appropriate ones to get my speedo accurate. I called a couple places and one told me I needed an 8-tooth drive gear and a 20-tooth driven gear for a TH-350/NP205 combo, 4.10:1 gears, and 31 5/8" nominal tire height 33x12.50 R16.5's. So, assuming he's correct--WHERE THE CRAP can I find such gears? Everything I've found that's the right tooth count is for TH-350 trannies but nobody can tell me if those gears fit in the t-case. My guess is they don't so can you guys help me out here?

10-18-2007, 02:19 PM	#2
72Cheyenne454 Registered User Join Date: Apr 2007 Location: San Diego Posts: 457	Re: NP 205 and speedo gears Try Quad 4x4. They specialize in NP205 parts. I know I've seen speedo gears on their website. www.quad4x4.com 1-406-446-2427

10-18-2007, 02:40 PM	#3
utvaquero59 Registered User Join Date: Aug 2007 Location: St. George, UT Posts: 70	Re: NP 205 and speedo gears 72Cheyenne, Thanks, they've got a drive gear available (7 tooth) assuming mine's plastic--can anybody confirm whether '71's had plastic or metal drive gears? The only thing left to decide, assuming the plastic gear works in my t-case, is where to find an 18 tooth driven gear. These fit into the base of the speedo cable, right? It's been a long time since I messed with speedo gears and cables. But, if it does, I just replace whatever gear is there with an 18-tooth gear that fits and I think I should be in business.

10-19-2007, 01:32 PM	#4
utvaquero59 Registered User Join Date: Aug 2007 Location: St. George, UT Posts: 70	Re: NP 205 and speedo gears So, a little more digging shows me that "early," NP205s had steel drive gears, "late," NP205's had plastic ones but no clear definition of what years comprise "early," and "late," t-cases. Any more help? Yes, I know, climb under the truck, pull the speedo cable and look. Arghh!

10-19-2007, 02:29 PM	#5
bdozeraz Registered User Join Date: Jun 2007 Location: Phx, Az Posts: 51	Re: NP 205 and speedo gears I haven't seen any different speedo gears for the 205. I took mine to a local speedo calibration place and they made an adapter that hooked to the speedo output on the 205 and the cable hooked to it. It cost around a hundred bucks for the whole deal. It seemed a little pricey for what took them about 10 min, but my speedo is correct now.

10-19-2007, 08:02 PM	#6
utvaquero59 Registered User Join Date: Aug 2007 Location: St. George, UT Posts: 70	Re: NP 205 and speedo gears OK so I got up under there today to discover steel drive and driven gears, 5 tooth count on the drive gear and 19-tooth count on the driven gear. I also have a question for those more knowledgable than me: what's the proper lube for the 205? One source said Dexron II, another said GL-5 or its Mil-spec equivalent.



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