NP200 Heat

[rboltz]

I know there has been reams of info here about the NP200 but I can't find my exact answer in the archives.

Hot day here today and I took the truck for a 30 min. ride around the country roads, just to warm her up and charge the batteries. It's been sitting in the garage for many weeks. Got back and decided to crawl under and feel the transfer case as I have never done that. It was warm to the touch. Not hot, just warmer then body temp so I would guess about 110-120 degrees as you can put your hand on it comfortably.

Is that too warm for such a short period of 45 mph or about normal? Do they always get warm, even if everything is fine?

[Duane]

the seals would survive forever if thats all the temp got to, if I remeber right, when I worked on the race team, we use to see seal failure when we went past the 250 degree mark, Mobil 1 gear oil brought down the temp 30 plus degrees. some of these trucks never see an overheating problem for some reason. so if thats all you see, you will be fine

Duane

[Barrman]

Anything less than around 220 is nothing for the NP200. Just driving around will get it warmed up some. What about your T98, differentials and hubs? They were probably all about the same "warm to the touch."

I flat towed my M715 to an event a few months ago behind the M35 Whistler. Never hitting more than 53 mph gps speed. 92 miles later and the t-case was at 232 from just being pulled. That is with Mobil 1 synthetic in it.

[randyscycle]

Yeah, if you could reach under and actually keep your hand on the transfer case, you're doing great.

With my temp gauge in mine, it will hang around less than 180F if I drive around under 45MPH for about 30-35 minutes on a hot day like ususal summer here in VA. If I push it up to around 50-55 it will climb up to 220F. If I keep pushing and drive at 55 for more than 10 miles or so, it will rapidly rise above 230F and keep going until I slow down or stop. The trans temp gauge ends at 320F and it has been there if I pushed it home above 55MPH.

All this said, I have not had the seals give out yet, and they were replaced with new ones from Memphis equipment two years ago.

Keep in mind, all this is information from running 38" tall tires too, not the stockers, which will actually make this happen a little faster.

[rboltz]

Today we went to the Jeep show and drove at 40-45 for an hour. When we came back, I checked temperatures again. Front Differential; cool, transmission; high warm, transfer case; hot, rear differential, warm.

I would guess the transfer case at 180 or so. No leaks, no hot smell but boy does it sing!!!

[fng]

I haven't made it yet but before I'm done I plan to make an airscoop of sorts for mine. It may be a little crude looking once I get it installed but in my pea brain it can't do anything but help. Probably use some scrap sheetmetal and attach it to the frame beneath. I'll post pics when I get it done.

[randyscycle]

40-45 is right in the happy zone for the NP200. You'd probably never have any overheat problems there at all. Push it above about 52 MPH and thats when the heat becomes an issue. And yes, they do sing!

Nice meeting you yesterday!

[brute4c]

Mine doesnt like over 50 mph if one drives for more than an hour in the spring hrough fall...in the dead of winter at -20 or so, it doesnt seem to matter too much.

I have thought about a scoop...sheet metal with a large font opening and a small one in the rear close to the case...something that could be unbolted easy for off road...

but...

in the end, I see the het as a sysmtom of the design made for a purpose that I no longer have...keeping it to 50 ma on the highway isnt hat I want...so an NP205 and poof...problem solved.

Although I understand keeing it stock.