Author Topic: 4 wheelin' with the NP205 Transfer Case & 4-speed 117 mm Transmission  (Read 1093 times)

Offline DouglasBeale

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So I got this truck a few months ago and have been working on it to get it ready for winter. I'll use it for plowing my driveway, hauling materials like gravel, hay, or mulch. I wouldn't call my property a farm, but maybe it'll be a gentleman's farm someday (just bought the place this past spring). To get in the field behind my house is a big hill with no proper road, and the driveway is also severely sloped. Both the driveway and fields access look like about 30 degrees at the steepest parts.

I have the granny gear (stick says L, 1, 2, 3), but normally don't use the low, except going up to the field with the 4 wheel low engaged. It sounds like it's winding out, but it goes up really smoothly and this is basically a grass covered hill with exposed topsoil in places- it's steep and slick. I read about the low gear for throwing hay without a driver, pulling stumps and heavy loads, but not really driving anywhere. First question is am I using this low/low-4 gear wrong? Someone told me I should using it for plowing, but it really sounds like its winding out at a very low speed.

I actually don't like to put it in 4 wheel drive too much because it feels real hard to move the shifter. Actually it doesn't want to shift at all at times so I put it in 1st gear bump it a bit maybe once or twice, then it seems to shift normally. At this point I can catch all 4 positions relatively easily... it's still just a little punchy, but I can feel it moving from one position to the next. Getting it out of 4low is basically the same thing - It's a pain in the butt. I would have to say I haven't really driven in 4h so I couldn't give any details for that gear. I've tried it hot, cold, engine on, engine off, in gear out of gear..., but usually operate the transfer case with the truck running, and the transmission in neutral and of course the hubs locked.

I've read the NP205 is super reliable, so I'm wondering does this sound normal, or am I doing something wrong?

I'm also having a little trouble when I turn into my driveway. It's steep from the get-go, so I kinda glide in, and slide it into first as soon as it'll allow, I might get a little bucking right off and have to feather the throttle down and crawl up always in first gear.

Also, if any of you guys are pushing a plow... Any advice would be greatly appreciated.








« Last Edit: November 05, 2018, 08:54:13 AM by DouglasBeale »
1986 Chevy K30
4WD Dually
Four Speed 117mm Transmission
NP205 transfer case
Quadrajet

Offline csdineley

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Re: 4 wheelin' with the NP205 Transfer Case & 4-speed 117 mm Transmission
« Reply #1 on: November 06, 2018, 11:47:47 AM »
Don't know if it's normal or not. But my np205 is the same. As for Low Gear it's really handy to have, but I hardly ever use it. Unless you want to crawl along under 5 mph. Or have a heavy load your trying to move.   
1987 V20 Custom Deluxe, Vortec 350, SM465,Np205 14Bff 3.42

Offline Irish_Alley

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Re: 4 wheelin' with the NP205 Transfer Case & 4-speed 117 mm Transmission
« Reply #2 on: November 06, 2018, 08:54:09 PM »
personally ive only used 4 low when in a mud pit, other than that im in 4h and granny in the snow or just creeping around. as far as sliding into the driveway is this in 4wd? if so the axles will bind up and fight each other when in 4wd and thats normal. i wouldnt do it too much and it may break something like an axle shaft or the ring and pinion.
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Offline DouglasBeale

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Re: 4 wheelin' with the NP205 Transfer Case & 4-speed 117 mm Transmission
« Reply #3 on: November 11, 2018, 05:43:29 PM »
as far as sliding into the driveway is this in 4wd?

No, that's 2 wheel
1986 Chevy K30
4WD Dually
Four Speed 117mm Transmission
NP205 transfer case
Quadrajet

Offline wildweaself

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Re: 4 wheelin' with the NP205 Transfer Case & 4-speed 117 mm Transmission
« Reply #4 on: January 18, 2019, 07:46:07 PM »
Your trans is the SM-465/NP205 combo. The exact same as what im running in my truck. They are pretty much indestructable but they can be difficult to operate to someone that hasnt used a setup like this before. Its a true machine that you have to make do what you want. Its not your modern day trans or t case that just glides in and out of gear. Chevy put this trans in everything from their 1/2 ton trucks all the way up to dump trucks.

Just a couple things to note of the "problems" you have which are pretty normal ops for this setup.

1. The whining you are hearing in L is because the "granny" gear is straight cut gears so they will be noisy. If you go much more than 5 mph or so it will scream and your engine will be revved out quick. The ratio for L is 6.55 to 1 and it is unsynchronized so it will be impossible to shift down into L while moving.

2. The transfer case being difficult to come out of 4 hi and 4 lo is because you are not relieving the tension on the drive train before trying to shift it. If its giving you problems put the truck in neutral and release the brake then shift out of the 4wd gears. If it still doesnt want to go then roll foreward or backwards without turning and try again. If its still a little rough then get the truck rolling just a very small bit and shift out of the gear. Its only hard because of the tension in the shafts from turning and such while you were using 4wd.