NP 200 oil cooler?

[Barrman]

Some of us long time members have a personal theory or experience with this and stick to that. Here is mine.

If drive shaft rpm exceeds 2500 rpm on a NP200 for more than 30 minutes 9 out of 10 will over heat. Even with synthetic oil and a direct drive conversion.

Either keep below that speed which is 48 in a stock truck with stock tires, rebuild the transfer case which seems to fix it for just about every one that reports back or get a different model transfer case.

I found a divorced 205 after mine would get hot. But, while still driving the truck collecting parts and pieces I discovered anything faster than Warp Speed is just noisy with so much more buffeting with the top off. I decided to just drive slower and enjoy. If I need to get somewhere fast I drive something else or plan ahead enough to take the M715.

To me that is what this all comes down to. If speed is your goal, the M715 will never satisfy in my opinion.

[Nailhead]

I took mine on a 300-mile summer road trip a few years back, and had no issues with T-case overheating, but I almost never exceeded 50 mph indicated, and I have Amsoil 75-110 oil in it. Exhaust heat got the floor hot enough to melt a plastic tool case, but the transfer case (with that exhaust right next to it) worked just fine.

Based on my experiences with a diesel-converted M37 running the same t-case & 4.89 gearing & this truck, I also believe avoiding heat-related issues with the transfer case is all about keeping drive shaft RPM below a certain figure: I could drive that M37 all day long at 65-70 with no problem because of its taller gearing, and 50 works fine in the M715 with stock gearing. It might put up with a higher speed, but I’m not interested in trying it.

[Don Cavey]

I wonder if my truck in Germany had a warm NP-200 after this trip on the Autobahn? Yes, the speedometer was wrapped up rather tightly.

[plumas.placer.miner]

Again, not having driven my truck for more than 4 miles, I am not sure it the T-case will overheat or not. I am just thinking ahead.

My claims are 3 hours away from where I live. It's no problem if I am driving in my Tundra pulling a trailer...two hours on hwy (up and down hills) and another hour up a single wide dirt road for another 26 miles (15-20 MPH).

But consider that drive in the M715... pulling a loaded trailer! The truck and the trailer will be loaded down with camping and mining gear for an entire month in the woods. Suffice it to say, if I overheat that T-case, I had better change the T-case oil before I head up the dirt road or risk being inoperable on that single-wide road, blocking traffic. Not a comfortable scenario for anyone on that road.

I am just trying to plan ahead. I hate inconveniencing other people because I was a dumba** and didn't think things through. If I can think of a way to keep that from happening, by planning ahead, I want to do it.

By the way, I once got a truck stuck in those mountains and had to hike out 20 miles one night after a full day of clearing roads with a chainsaw. Then I had to go back up the next day with a tow truck. That was 36 hours of hell! I'd rather avoid that scenario again, if'n you know what I mean.*

[brute4c]

I would have thrown in what Barrman said...although probably not as well said as he did....
That is the sum total of the topic over the last 20 years of real world experience and discussion.
Its a good tcase to a point...that point is where the old flat head engines with their limited rpm potential end and the modern, ohv, motors with higher rev potential start. The NP200 was designed for the flatheads...the NP202 and NP205 were designed for the ohv types...with the NP202 being scarcer, larger and higher rated. Either will work in the M715 as both have been used.
This is the easiest, most durable and least long term problems solution to the NP200's propensity for heat creation.

[plumas.placer.miner]

At the beginning of my build thread, some months ago, someone told me they thought I had an NP 205 in my truck based upon a photo I posted.

Can someone tell me how to tell the difference between the NP200 and the NP205 from looking at it?

Thank you in advance!

[Nailhead]

At the beginning of my build thread, some months ago, someone told me they thought I had an NP 205 in my truck based upon a photo I posted.



Can someone tell me how to tell the difference between the NP200 and the NP205 from looking at it?



Thank you in advance!

The 205 is larger and will have a round aluminum NP identifier tag on it.


Sent from my iPad using Tapatalk

[Barrman]

The 200 has no PTO port.

[plumas.placer.miner]

I don't see an identifier tag, but it definitely does have a PTO port. It must be a 205. YAY!

I was looking online to see if I could find one last night. If I wanted one, it seems like I would have to buy a donor truck with a NP205 already in it, or do all those mechanical conversions myself.

[Barrman]

Is there an aluminum panel on the passenger side rear in the same shape as the rear drive shaft output housing?

6 or 8 bolt PTO?

Trying to narrow down between 205 and some of the others.