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I found a great deal on a M715 with no motor that I am thinking about buying for a tow rig. It would recieve a fuel injected engine most likely. I need some links to pages about these great trucks that do not just give specs. Any help or pictures would be greatly appreciated.
 

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You will need to replace the T-case and tranny as well (if you have not already planned to) The T-case-NP-200 (IIRC)-that came stock in those is not rated to much over 50 mph and can burn up. Brad gave you the best link for them. Alot of people over at the IFSJA have them as well. Follow the link in my sig.
 

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I have an M-715 that I use as my daily driver/tow rig. I love it. I have a Cummins turbodiesel/ NV4500 combo in mine.

Couple of things to be aware of:

The 715's early 70 rear can only be geared to 4.56 as high speed carriers are impossible to find for it.

The brakes are a bit of a pain to get parts for.
 

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The T-case-NP-200 (IIRC)-that came stock in those is not rated to much over 50 mph and can burn up
I have heard this before, but no one can explain why. Bushings instead of bearings? High rotating mass? What? Also, the 202 seems to survive at speed, so whatever it was must have been fixed by then. Just curious to find this out, as i like the early NP cases better than the 205, due to factory twin sticks anda (seemingly) stouter design.
 

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www.m715zone.com is the best bet. (I am a founding member of this and the yahoo group/club from before as well). If it isn't here, they will have links to what you want to find.

www.m715.com is my other site, and unfortunately I haven't had the time to update it. And my truck is about 2100 miles away from me right now, so it will stay that way for a while.

The gear oil will heat up, boil, froth up, and loose all lubricating properties when the 200 is sustained for continual high MPH. This is not exact because many people reports different variants in possible speeds and time frames before frothing.
People have added Lucas oil to keep it under better control. And people also relocate the rear output to the center out instead of using the stock passenger out for the rear. Swapping the Ebrake drum for the driveshaft. Otherwise you are constantly running power through all the gears and generating a LOT of heat.

Most people who drive them often and far swap to a 205. Or the IHC version of the 202 is another choice, but not usually as easy to find.

And if you want an OD unit, search for one in the power wagon lists. They used the same Tcase. And they have the OD that bolts onto the back of the tcase. No drivesaft mods needed (I think any way).
 

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I have heard rumors that the heat is caused by corrosion due to moisture. These rigs usually have extremely low mileages (never seen one over 50K miles) and they tend to sit for quite some time. Then the internals of the TC could get some surface rust, or maybe the gear oil breaks down. This makes some sense, but why does it only happen to NP200's??? :)

Mikel
 

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People have reported a lot of pitted bearings in the Tcase. I would imagine that this is a large part of the issue. Also that the bearings seem to be pretty loose in a lot of aplications.

Never mind that this tcase is ancient! The M37 ran this tcase for it's life term as well. VERY strong, but has issues.

A friend replaced all bearings in his and ran synthetic oil. Never had any problems with it after that, and he would do long tows with way too much weight at 75 mph continuously. WillieM715 on the boards. I felt his tcase after some driving and it was pretty cool to the touch all things considered.

And when you run with the lower rear output you are putting strain on all the gears creating a lot of heat.
If you want to run the tcase, inspect/replace the bearings. Consider moving the rear driveshaft (202 is the only other lower drop rear output that fits right in place), and run some Redline Shockproof gear oil. I recommend running the redline in the tranny as well for similiar reasons.

Btw, many of these had synthetic gear oil in the axles from the military. So gears are usually in great shape, even after sitting. It is usually the bearings that develop pitting where it has been sitting.
 
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