1968 M715 - Highway Drivable

[harkless25]

First let me say, I am really glad you all are here. My wife just bought Gilberto's M715 and we are super-excited. I had a 1948 Willy's as a kid and a 1967 Baja Bug, but both of those off-roaders bow to the beast that we just purchased. The only real issue we have is getting it to off-road locations that are 1-200 miles away.

So here are the fundamentals: She is a stock M715 cargo carrier with the PTO winch, except she has a very strong 1980 Chevy 350. Our strong lean is to preserve this where possible. I am concerned about burning out the NP200 transfer case, were we to go on road trips that require highway driving.

1. If we have the NP205 installed and leave everything else (transmission, gearing ratios, rims and tires, etc), will she be able to sustain 1-200 miles of 60mph driving?

2. Is this the best way of achieving this (without sacrificing off-road capability) with the smallest amount of changes to stock set up?

3. if there a preferred method of making the adaptations necessary to put the NP205 in (it is hard to gather all the different threads into a coherent build plan)?

4. Do any of the adaptations impact my PTO winch? and if so, what can i do to get her highway drivable without losing the PTO winch?

If my questions show my ignorance, bear with me. I am new o this set-up and only a little mechanical, this job will be farmed out to a local 4WD shop - but even they are ignorant of what was best for an M715.

Thanks!

Harkless25

[militarypotts]

That is a nice truck, congratulations on it. My truck is a 1968 bone stock original, except for the 1100x16 XL Michelens. (you can click on little picture to see it). Their are plenty of people on this site that will be answering all your question, so don't hesitate to ask any and all questions you have about the truck. Since I don't have a winch, I'm not sure about the effects of a NP205. I don't believe their will be a problem, but just check back here, and I'll guarantee you'll have a whole lot of responses to your question. Welcome to the Zone, you'll enjoy the interest we all show for our M715's.

[md1970]

60 Mph is a lot of mods to make happen. tires,r&p gears, engine swap just for starters

[Troop ISP]

If you go to the Grim Jeeper website, you can enter information to figure out RPM's at a given speed. With 38 inch tires and stock transmission, you will be running 3000 RPM at 58 MPH. Now that is manageable for a SBC, but your fuel economy will be terrible. Of course these trucks were never built for economy.

You can search for threads on 205 transfer case conversion. There are members on here who have adapted the parking brake from the 200 to the 205. You could always do a spring over/shackle flip and run bigger tires. That would bring you engine RPM's down on the highway.

There is a great deal of information available. Go to the archives and search for transfer case swaps, spring over conversion, and other information. There are a lot of great ideas that have been written about over the years.

Welcome to the Zone.

[Blitz]

Your stock Braden LU-4 winch should be run off of the T-98 transmission that you have now.

Switching out to an NP 205 transfer case , should not affect the winch operation.

*** "Although" ***

You "could" run the winch off of the NP 205, if you wished to do so...
with a PTO for the NP 205, and a longer winch drive shaft.

** You cant do that with the stock NP 200 transfer case, as it has No PTO port. **

Yep, You are good to go **winch wise**, switching the transfer case to an NP 205, and leaving the winch controls and driveshaft AS IS, stock.

No change required...
But... Yes, you have another option with the 205 *if you wish.* that the NP 200 stock T case does not allow you.

I personally would leave it stock for now ( the winch) and seriously consider the np 205 case.
( And front wheel hub lock outs, so you are not full time 4WD ) Warn M 13's

Nice Truck.

I bet You guys are smiling ear to ear.

welcome to the zone !

[Blitz]

One more thing...

finding WARN lock out hubs that fit our trucks is very difficult.

It IS possible to "twin stick" the NP 205 transfer case, where you can disable the front wheels ( front drive axle )... so you can go down the road in 2 WD.

( Please members, correct me if I'm wrong )

Transfer cases get confusing...


it also is possible to retrofit the existing emergency brake drum and band and controls, on your existing NP 200... to retrofit the NP 205 and still function.

Its gonna require fabbing up some mounts and parts, and I cant walk you through it easily...

But when you switch to the NP 205... you will otherwise lose Your parking ( emergency ) brake drum and controls.


Jump right into rocket science why dont ya


Welcome again to the Zone.

were you known as "Doug" in School... Harkless ?
Just curious.

Blitz

[md1970]

forgot to add you need to update the brake m/c to split system for safety reasons

[brute4c]

The 205 is an updated version of the 200...BOTH allow for one to drive without the front axle being driven by the driveline...all one needs to "turn off" the front axle is the lockout hubs.

As far as driving a stock trans truck with a 350, stock gears and tire size at 60...I drove a STOCK 230/trans/tcase/gears and tire size at 60 mph until I got a temp gauge on the tcase and found that to be a problem for the NP200...in the winter when heat is not a problem, I would drive up to 60 mph all over...in the summer, the tcase limited me to 45-50 until evening/night cooling let me go faster.
I would say that if your 350 can take the 3500 rpms at 60 due to it being in good condition, then you can do 60. I would use lockout hubs on the front axle and I would avoid paying your fuel costs...you know it will cost more than other stuff to run at 60 though so I hope you are already prepared for that.

Bottom line, the trans and axles WILL handle 60 mph...if your engine and a decent condition and well mounted NP205 is installed with that and lockout hubs on the front, I see no problems here...I would run one that way and I have run one that way...with a 230 even.

[harkless25]

This is great information. The truck already has power steering and selectro lock outs on the front hubs. And i am not overly concerned about fuel efficiency, just don't want to be stranded on the side of a highway or in the middle of nowhere with burned up transfer case. question, where do you get a temp gauge for the transfer case? and how do you put it on?

And we don't want to go fast, just drive at a safe speed on the highway. Sounds like the NP205 could get us there.

So if I have the 4WD shop put the NP205 on what should i expect to pay?

Scott

[harkless25]

curious as well, what temperature would be normal and high ranges for a transfer case?