Transfer case sprocket and chain

[strantor]

Who knows something about transfer case sprocket and chain? I had the idea to use it to transmit some rotary power, as I found the specs for standard ANSI roller chain are actually not that impressive. I can't find any specs for the t-case chains and sprockets, but given they're used in vehicles making 400+hp from the factory, I assume someone has the numbers, and signed off on the components being grossly overkill for my application (just like I like it).

The sprockets look like ordinary spur gears. Are they?

There "seems" to be less than a handful of different pitches & chain widths, with most OEMs using the same parts in their transfer cases, so it "seems" as though you could potentially take a chain out of a dodge, a sprocket out of a jeep, and another sprocket with a different tooth count out of a GMC, and as long as they're all the same width, you could put them together for other-than-1:1 gearing. Am I deluding myself? Surely it's not as simple as that? Nothing is ever that easy.

 

[Ulma Doctor]

the Borg Warner corporation made the predecessor and the Qudra-Trac back in the 70's and 80's
it had spur gear like teeth on the gears and a modified toothed chain profile
Borg Warner made transfer NP204 cases for Jeep, Ford, Doge, GM
so these gears would be interchangeable, because they are the same gears.

roller chain is sometimes very strong, #80-1 chain is highly improbable of breakage unless you can develop in excess 40,000 lbs of pressure
even milder chain #35-2 will still take in excess of 4,300 lbs to break

your normal 10 hp 3phase motor develops less than 50 ftlbs of torque @1740rpm

 

[pontiac428]

New Process Gear was owned by Chrysler. They sold transfer cases to GM until GM acquired/started up New Venture Gear. Borg Warner is a conglomerate corporation that buys other companies. It's hard to tell who owns what, but one thing is for sure, those chains are strong. Take that 400 lb-ft and multiply by the 1st gear ratio and the low range ratio- that's tons of torque.

 

[Superburban]

Not near an expert, but I did stay at a holiday inn once.

Within models, I believe you can swap many parts. Ie, a NP 241, between a dodge, cheby, and ferd. The only exceptions I know of, the old NP203 had two different chain sizes throughout its run. I also think the NP241DHD (came behind a dodge cummins), also has a different chain then a more or less normal NP241. I don't know how much different gearing you can get, all I have taken apart, looked to be about the smae sprocket size.

I do not recall running across any capacity specs, but did find some places that could make them to your requirements. Search for morse chain.

the Borg Warner corporation made the predecessor and the Qudra-Trac back in the 70's and 80's
it had spur gear like teeth on the gears and a modified toothed chain profile
Borg Warner made transfer NP204 cases for Jeep, Ford, Doge, GM
so these gears would be interchangeable, because they are the same gears.

The NPXXX transfercases & Transmissions were made by New Process, a spinn off from spicer gear corp, and later merged with GM's Muncie gear, to make New Venture gear corp. Then GM sold out to Chrysler, which later sold it all to Magna international.

Borg Warner, went through many mergers and acquisitions, and on to bigger and better things.

 

[strantor]

the Borg Warner corporation made the predecessor and the Qudra-Trac back in the 70's and 80's
it had spur gear like teeth on the gears and a modified toothed chain profile
Borg Warner made transfer NP204 cases for Jeep, Ford, Doge, GM
so these gears would be interchangeable, because they are the same gears.

Thanks for the tips. Ill check and see if all np204 have the same # of teeth, or if it would be possible for me to achieve gearing other than 1:1.

roller chain is sometimes very strong, #80-1 chain is highly improbable of breakage unless you can develop in excess 40,000 lbs of pressure
even milder chain #35-2 will still take in excess of 4,300 lbs to break

your normal 10 hp 3phase motor develops less than 50 ftlbs of torque @1740rpm

Yeah the tensile strength is as good or better than one would think from looking at it. Tensile strength isn't the problem though, speed is. Your example of #80 chain on a 10HP electric motor is only achievable with a 4 pole/1800 rpm motor, and only with sprockets >=13 teeth, in an oil bath. If it were a 2-pole/3600 rpm motor you're screwed, all you can get out of #80 chain with any combination of tooth count and lube scheme is 5.25hp.

Now in my case, coupling a 50hp+ internal combustion engine @4k+ rpm, that's nowhere near on this chart

 

[strantor]

one thing is for sure, those chains are strong. Take that 400 lb-ft and multiply by the 1st gear ratio and the low range ratio- that's tons of torque.

Good point. These chains are after transmission gearing so they might not be any good for high speed either. In order for the t-case sprockets to see 4000 rpm you'd need to be in 4-hi flying down the highway in OD at 140mph. I think that would be generally advised as a bad situation to be in with 4wd engaged, but I'm sure it's been done, sometime, by someone. I need to find that guy and ask.

 

[pontiac428]

I need to find that guy and ask.

That guy is right here, amigo!

 

[Superburban]

Any drive system (Chain, V-belt, serpentine belt), will be affected by centrifugal forces, For higher RPM's, look to something lighter.Like maybe the big wide drive belts that some motorcycles used, or blowers on the big engines. Or use several Vee belts.

Some of the first front wheel drive transmissions used a chain, that ran at or close to engine speed. maybe some still do.

 

[strantor]

Any drive system (Chain, V-belt, serpentine belt), will be affected by centrifugal forces, For higher RPM's, look to something lighter.Like maybe the big wide drive belts that some motorcycles used, or blowers on the big engines. Or use several Vee belts.

Some of the first front wheel drive transmissions used a chain, that ran at or close to engine speed. maybe some still do.

Ah, yeah motorcycle drive belt is probably the ticket. Or motorcycle chain*. Thanks!

* I wonder what is the fundamental difference between motorcycle chain and ANSI roller chain that makes it ok to wrap motorcycle chain around a tiny sprocket running 12k rpm, which is not possible with ANSI roller chain.

 

[Asm109]

Two things. Motorcycle chain uses better grades of material and parts made more precisely.
Second. ANSI chain is rated for continuous hp. 24/7 for 50,000 hours.
Motorcycles dose out full hp a few seconds at a time. Mostly cruising the chain sees 1/10 peak hp or less.