Printable View
I have heard that someone has found a passive oil cooler that bolts to the PTO flange on the NP200. Do any of you think that would work to keep temps down?
I know that they make 'em for some t-cases, like this:
https://imagizer.imageshack.com/img921/8308/b5XFLk.jpg
It's about 3 hours of driving to my claims in the M715, and the first two hours are highway hours (45-50 MPH) and some real hills. I can see (and smell) the overheating NP200 coming.
I don't want to install a pump and run lines.
I have wondered about cooling fins, too. Not sure how to try some and keep my PTO winch.Quote:
Originally Posted by plumas.placer.miner
Sent from my moto x4 using Tapatalk
I thought that the PTO unit is mounted on the side of the T98 transmission, and not the NP200 transfer case.
Oh, duh. Of course it is. [emoji849]Quote:
Originally Posted by jeepdan
Sent from my moto x4 using Tapatalk
I have read on other fora that some people just put extra oil in the T-case, and that solves the overheating problem.
I dunno though...My Gramps was a Ford mechanic and he always told me that too much oil is worse than too little oil...up to a point.
Others just say to get used to the idea that the NP200 overheats at highway speeds...period. If I don't like it, change to the NP205. I think I read that on this forum somewhere.
Some on other fora said that AT Fluid is best used in the T-case, while others recommend 50 wt oil. I used the 85-90 gear oil, but I can't say if it overheats because I haven't driven more than 4 miles yet. I know...that sucks.
I'm trying to get in front of the T-case overheating issue, if possible.
try Charles at :
http://www.mseriesrebuild.com/index.html
he at one time was offering some type of cooler
Sounds great.Quote:
Originally Posted by bmac6026
"NP-200 transfer case, with a cooling system. Features a 12 or 24 volt pump, cooling core with electric fan, and a spin-on oil filter. On dash monitoring system including an oil temperature gauge, and pilot lamp for monitoring pump and cooling fan functions. This system offers the oil cooling necessary for heavy hauling, towing, and sustained operation at on highway speeds. All system components are protected from damage by expanded metal shielding."
Sent from my moto x4 using Tapatalk
I've driven my M715 on the highway at 65-70MPH all day (800 miles in one day) and never had any heat issues. But I do have 4.10 gears...
Given that the gears are the same as in a NP205 and the bearings are not all that different, it is a great mystery to me why these things generate so much heat.
I think the extra heat is caused by not having a direct drive, which lead people to switch the yoke on the backside of the t-case. Some 200’s build up more heat or noise than others. I’d see if it heats up or not and leave well enough alone. My 200 was crazy loud and got super hot. I swapped in a 205 and it fixed both heat and noise.
Mine is direct drive. The only noise I get is when coasting on the highway. GRRRRRRRR :confused:Quote:
Originally Posted by gonz
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.
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.
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.
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.*
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.
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!
Quote:
Originally Posted by plumas.placer.miner
The 205 is larger and will have a round aluminum NP identifier tag on it.
Sent from my iPad using Tapatalk
The 200 has no PTO port.
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.
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.
I went and climbed under the truck again to take a look. I was going by memory, but my memory isn't what it used to be... apparently. There's no PTO port on my T-case (just on the transmission), and the circle on the passenger side on the rear is blank.
That spells NP200 alright.
Sorry for the false set of parameters, but thanks for helping me sort it out.
I am wrestling with the windshield wipers at the moment.