205 tc from sm456 to th350 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

stan79chevy · 12-11-2003, 03:45 AM

is there a way to convert a 205 that was built with a sm456 to make it work with a th350. will i only need the adapter? is it possible? do any of you know any websites with good 205 tech articles.

i have a 203 now with manual front hubs and i want to be able to shift into 4wd or from 4wd to 2wd without getting out. and my 203 is going to need a chain soon i have been told

thanks

**MJN** · 12-11-2003, 11:02 AM

There is a way to convert them but it is more hassel and more money than finding one that is already off a 350 tranny. The input shafts are different from sm465 to an auto tranny.
If you have a 203 now and don't want to get out to shift into four wheel, then stay with the 203, those are the full time transfer cases and 205's are the part time cases. 205's came with lockouts and 203's came with just caps where the lockouts should be on the front axle. Otherwise with a 205 you have to get out and unlock your hubs and then shift the t-case into two wheel drive, where as the 203 you can shift back and forth anytime.

**kwmech** · 12-11-2003, 11:42 AM

You will need of course an adaptor for the automatic and you will nedd an input gear for the 205. It takes me about 20 minutes to change the input gear in the 205

Scrub · 12-11-2003, 12:47 PM

There is an input shaft on e-bay right now, but the guy has no pics and some dubious feedback.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2447737896

I think you could find the whole setup cheaper than what he is asking.

http://www.offroaddesign.com/NP205tech.htm

explains most of what you need to know.

good luck

DaHateTank · 12-12-2003, 04:39 AM

You don't have to get out to shift into 4WD with a 205, either. Same as what you have now, only with no POS chaindrive...
( since you have lockouts, Ill assume that the T-case is converted)

You just have to have enough on the ball, to lock the damn truck in BEFORE you leave. It doesn't hurt anything to drive in 2HI with the front end locked up. Wears more than unlocked, and kinda noisy, but no worse than a full-time truck with a 203...except for not having that stupid differential in the T-case.

My truck ( SM465/NP205) is locked in all winter...

shouldn't be too hard to find a TH350/NP205 setup. I actually threw one away, many moons ago...

-M

alf4444 · 12-12-2003, 02:59 PM

Im doing the same thing right now. The key is to be patient when looking for parts. I had offers from guys selling their adapters for up to $250

but finally got lucky and found one for $40. The drive sleeve on ebay is overpriced the guy emailed me his reserve he said $90 you can get them new for $110. Now that i have an adapter a local 4x4 shop is changing my input shaft and selling me the drive sleeve for $200. The only thing now to buy is my twin stick shifter from echobit $130. The only reason all this is worthwhile for me is the 205 i got was free (somewhat,I got it in a trade) and it was already twin sticked

Scrub · 12-13-2003, 10:06 PM

350 to 205 Adapter on e-bay

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2448652364

The guy has 100% positive feedback

Good luck

stan79chevy · 12-14-2003, 12:05 AM

it just has the hubs..helped on gas milage..the kit for the 203 is around 200 and you still have to buy all the extras. i have a buddy who will give me a 205 from a sm456 another buddy has an adapter for the 350 so all i think i need to do is change the input shaft. i think im going to wait and do the 203/205 doubler since my 203 is still good. thanks for all the help everybody that website has the stepby step instuctions should be easy to do just hard on the wallet for them adapters

thanks
stan

12-11-2003, 03:45 AM	#1
stan79chevy Registered User Join Date: Sep 2003 Location: COVINGTON GEORGIA Posts: 477	205 tc from sm456 to th350 is there a way to convert a 205 that was built with a sm456 to make it work with a th350. will i only need the adapter? is it possible? do any of you know any websites with good 205 tech articles. i have a 203 now with manual front hubs and i want to be able to shift into 4wd or from 4wd to 2wd without getting out. and my 203 is going to need a chain soon i have been told thanks __________________ 79 chevy k20 350/350/205/D44/14bFF 4.56 gears rock LWB pimer black 01 S-10 ZR2 extended cab 4.3/4L60E/233 3.73 gear 31" DICK CEPEK CRUSHERS

12-11-2003, 11:02 AM	#2
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 2,974	There is a way to convert them but it is more hassel and more money than finding one that is already off a 350 tranny. The input shafts are different from sm465 to an auto tranny. If you have a 203 now and don't want to get out to shift into four wheel, then stay with the 203, those are the full time transfer cases and 205's are the part time cases. 205's came with lockouts and 203's came with just caps where the lockouts should be on the front axle. Otherwise with a 205 you have to get out and unlock your hubs and then shift the t-case into two wheel drive, where as the 203 you can shift back and forth anytime. __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com

12-11-2003, 12:47 PM	#4
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	There is an input shaft on e-bay right now, but the guy has no pics and some dubious feedback. http://cgi.ebay.com/ebaymotors/ws/eB...tem=2447737896 I think you could find the whole setup cheaper than what he is asking. http://www.offroaddesign.com/NP205tech.htm explains most of what you need to know. good luck __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

12-12-2003, 02:59 PM	#6
alf4444 Registered User Join Date: Dec 2002 Location: taylorsville, UT Posts: 778	Im doing the same thing right now. The key is to be patient when looking for parts. I had offers from guys selling their adapters for up to $250 but finally got lucky and found one for $40. The drive sleeve on ebay is overpriced the guy emailed me his reserve he said $90 you can get them new for $110. Now that i have an adapter a local 4x4 shop is changing my input shaft and selling me the drive sleeve for $200. The only thing now to buy is my twin stick shifter from echobit $130. The only reason all this is worthwhile for me is the 205 i got was free (somewhat,I got it in a trade) and it was already twin sticked __________________ 2011 CCSB GMC 2500HD DMAX 73 GMC 3/4 ton 4x4 96 Chevy 1500 STD Cab Shortbed Z71 Owner of WickedWolfRC.com

12-13-2003, 10:06 PM	#7
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	350 to 205 Adapter on e-bay http://cgi.ebay.com/ebaymotors/ws/eB...tem=2448652364 The guy has 100% positive feedback Good luck __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

12-11-2003, 11:42 AM	#3
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,405	You will need of course an adaptor for the automatic and you will nedd an input gear for the 205. It takes me about 20 minutes to change the input gear in the 205

12-12-2003, 04:39 AM	#5
DaHateTank Registered User Join Date: Aug 2002 Location: Iowa Posts: 119	You don't have to get out to shift into 4WD with a 205, either. Same as what you have now, only with no POS chaindrive... ( since you have lockouts, Ill assume that the T-case is converted) You just have to have enough on the ball, to lock the damn truck in BEFORE you leave. It doesn't hurt anything to drive in 2HI with the front end locked up. Wears more than unlocked, and kinda noisy, but no worse than a full-time truck with a 203...except for not having that stupid differential in the T-case. My truck ( SM465/NP205) is locked in all winter... shouldn't be too hard to find a TH350/NP205 setup. I actually threw one away, many moons ago... -M

12-14-2003, 12:05 AM	#8
stan79chevy Registered User Join Date: Sep 2003 Location: COVINGTON GEORGIA Posts: 477	my 203 has not been converted it just has the hubs..helped on gas milage..the kit for the 203 is around 200 and you still have to buy all the extras. i have a buddy who will give me a 205 from a sm456 another buddy has an adapter for the 350 so all i think i need to do is change the input shaft. i think im going to wait and do the 203/205 doubler since my 203 is still good. thanks for all the help everybody that website has the stepby step instuctions should be easy to do just hard on the wallet for them adapters thanks stan __________________ 79 chevy k20 350/350/205/D44/14bFF 4.56 gears rock LWB pimer black 01 S-10 ZR2 extended cab 4.3/4L60E/233 3.73 gear 31" DICK CEPEK CRUSHERS



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