np435 transmission rebuild - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kauaiman · 10-27-2020, 02:05 AM

I have a 1969 c-10 with a np435 4speed transmission. I have been scouring the internet ,but cannot find a good tutorial or write up on rebuilding one. I am getting a grinding noise when shifting into fourth gear. all other gears work fine.
Anybody have a good set of rebuilding instructions I could use? I have rebuilt other manual transmissions, but would like detailed instructions so I only have to do it once. Thanks

Wrenchbender Ret · 10-27-2020, 12:54 PM

They are easy to work on. The early ones had a weird syncronizer setup. They broke real easily. I imagine a replacement will be hard to find.
George

Orange Crate · 10-27-2020, 01:41 PM

Quote:

Originally Posted by kauaiman

I have a 1969 c-10 with a np435 4speed transmission. I have been scouring the internet ,but cannot find a good tutorial or write up on rebuilding one. I am getting a grinding noise when shifting into fourth gear. all other gears work fine.
Anybody have a good set of rebuilding instructions I could use? I have rebuilt other manual transmissions, but would like detailed instructions so I only have to do it once. Thanks

What is wrong with the factory overhaul manual?

**WorkinLonghorn** · 10-27-2020, 05:39 PM

X-2 on the factory manual. These guys supposedly have instructions too;

https://www.novak-adapt.com/knowledg.../manual/np435/

https://www.novak-adapt.com/catalog/...s/np435-parts/

Orange Crate · 10-27-2020, 06:32 PM

Here is the linky I couldn't find earlier for the overhaul manual for 1969.

http://67-72chevytrucks.com/vboard/s...d.php?t=558016

TwoFiftyShifter · 10-27-2020, 07:47 PM

What is the deal with these 435s? They appear to be like an SM465 but with closer ratios. Better ratios than the 465 for most of us. But only came in a few of our trucks, mostly came in Fords?

**WorkinLonghorn** · 10-30-2020, 01:33 AM

All of the Fords had the wide ratio model. The one that GM used in the light trucks was the 4.56 low gear model. Short throw, smooth shifting close ratio (well, a lot closer than a 465 anyway) transmission that is as stout as a 465. I like mine much better than the 465s I've had but if I was pulling a large trailer near the max gross combined weight limit, I'd like a 465 (or a TH-400). My truck was ordered as a camper hauler and I heard somewhere that these NP435 were considered better for this type of usage.

10-27-2020, 02:05 AM	#1
kauaiman Registered User Join Date: Jul 2010 Location: kapaa kauai Posts: 19	np435 transmission rebuild I have a 1969 c-10 with a np435 4speed transmission. I have been scouring the internet ,but cannot find a good tutorial or write up on rebuilding one. I am getting a grinding noise when shifting into fourth gear. all other gears work fine. Anybody have a good set of rebuilding instructions I could use? I have rebuilt other manual transmissions, but would like detailed instructions so I only have to do it once. Thanks

10-27-2020, 12:54 PM	#2
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: np435 transmission rebuild They are easy to work on. The early ones had a weird syncronizer setup. They broke real easily. I imagine a replacement will be hard to find. George

10-27-2020, 05:39 PM	#4
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,886	Re: np435 transmission rebuild X-2 on the factory manual. These guys supposedly have instructions too; https://www.novak-adapt.com/knowledg.../manual/np435/ https://www.novak-adapt.com/catalog/...s/np435-parts/ __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme.

10-27-2020, 06:32 PM	#5
Orange Crate Registered User Join Date: Feb 2011 Location: Under the Truck Dreaming Posts: 755	Re: np435 transmission rebuild Here is the linky I couldn't find earlier for the overhaul manual for 1969. http://67-72chevytrucks.com/vboard/s...d.php?t=558016 __________________ 72 K20 Custom Camper, D60, 14BFF, full roller 406 TPI w custom built ECU and yes..it has tow hooks...and a 5 speed

10-27-2020, 07:47 PM	#6
TwoFiftyShifter Registered User Join Date: Nov 2008 Location: Gwinnett GA Posts: 1,803	Re: np435 transmission rebuild What is the deal with these 435s? They appear to be like an SM465 but with closer ratios. Better ratios than the 465 for most of us. But only came in a few of our trucks, mostly came in Fords? __________________ 1982 K10 SWB 1987 V20 - Sold - Doh!

10-30-2020, 01:33 AM	#7
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,886	Re: np435 transmission rebuild All of the Fords had the wide ratio model. The one that GM used in the light trucks was the 4.56 low gear model. Short throw, smooth shifting close ratio (well, a lot closer than a 465 anyway) transmission that is as stout as a 465. I like mine much better than the 465s I've had but if I was pulling a large trailer near the max gross combined weight limit, I'd like a 465 (or a TH-400). My truck was ordered as a camper hauler and I heard somewhere that these NP435 were considered better for this type of usage. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme.



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