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Flat towing, Do the drive shafts neede to come out..

84CUCV

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One said yes and one said no, so i am askinf here, one trip will be about 14 miles the other will be about 80. Thanks mike
 
If it is a 4x4, just lock in the hubs and put the tcase in neutal. Leave the transmission in gear or park. /forums/images/graemlins/thumb.gif

If it is a 2wd auto pull the driveshaft or start it before towing and drive slow.

If it is a 2wd manual for that short of a distance just drive slow. For long distances I would say pull the driveshaft. I just lost a 4 spd after about 1000 miles of flat towing.
 
Why lock the hubs? I was just going to put the SM465 and 205 in neutral. thanks
 
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Why lock the hubs? I was just going to put the SM465 and 205 in neutral. thanks

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Put the SM465 in neutral, and UNLOCK THE HUBS.
I have been doing this for the past 3 years about 4k miles total, no problems.
 
Locking the hubs keeps the NP205 lubricated properly where as spinning the rear driveshaft only will starve bearings of lubrication and slowly kill the tcase. The reason for putting the transmission in gear or park is to keep it from turning. With the tcase in neutral the tranny doesnt need to be in neutral.
 
[ QUOTE ]
Locking the hubs keeps the NP205 lubricated properly where as spinning the rear driveshaft only will starve bearings of lubrication and slowly kill the tcase. The reason for putting the transmission in gear or park is to keep it from turning. With the tcase in neutral the tranny doesnt need to be in neutral.

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I could be wrong but if it's in neutral and no load if the gears spin, they get oiled from being in the oil no need for oil pumping or slinging to oil it, and as for the tranny and Tcase being in neutral, it's just a safety measure in case something falls on one of the shifters on hard braking and it pops into gear, I have a deisel that doesn't need ignition to start.
/forums/images/graemlins/dunno.gif
 
The NP205 does not get lubricated when in nuetral and only the rear output spinning (same with most 4 spd transmissions). The gear oil does not go high enough to reach that part of the rotating assembly. The gears will not be spinning unless the front hubs are locked in or the tcase input is spinning. Locking the front hubs and leaving the tcase in neutral is the way New Venture (New Process) recommends flat towing with their tcases. Though if you are only going a short distance you probably wont hurt anything. It took me over 700 miles to kill the rear bearings in a 2wd 4 spd with out pulling the driveshaft.

I know on the 6.2 diesel you may not need ignition to start it but you do need fuel and with the key off there is no fuel. Cant remember how your diesel was set up though.
 
I know you guys are dealing from real life instances,but when I was in the towing industry, it was a good rule of thumb, if over five miles pull the shaft, it only takes 5 minutes and is alot less trouble then replacing a trans. just my .02 /forums/images/graemlins/thinking.gif
 
Newbie member here, but will throw a recent flat tow into the mix. You guys with much more moxie than I on the subject can determine if what I experienced is the norm, or was it a operator (me) malfunction?

After action report for flat towing of the 85 K-5 Jimmy.

Towed the Jimmy (4 speed. 700 R-4 auto tranny) 250 miles up to Arizona high country behind motor home. Front manual hubs locked out, 700 R-4 tranny in neutral, 208 NP manual transfer case in neutral, key in first notch to allow steering wheel freedom of movement.

Towed for ten miles and checked, all appeared OK, checked again at 100 miles and found transfer case very warm & vent line was burping small amount of fluid. Checked again at 150 miles and found the transfer very hot, (sizzled saliva when spat upon) also by this time, it was really blowing tranny fluid (what it uses) out the transfer case vent line.

I proceeded to drop the rear drive line, continued trip with no other problems. reinstalled rear drive line on arrival and all seemed fine. Drove a couple hundred miles HWY and (very) rough back roads & 4x4 trails with no adverse effects noticed.

Dropped rear drive line, trip back home was uneventful as to towing. Now using Jimmy for local driving and have noticed no problems, so apparently no permanent damage occurred.

Have no idea as to problem unless the transfer case components do not take well to becoming driven, instead of drivers. The 208 NP transfer case does have an oil pump, so maybe it did not perform as intended. The thing is, there is no cooling of transfer case fluid under normal driving conditions, so what really gives, I have no real idea?

One thing I did noticed that seemed odd, with the transfer case in neutral, no input is induced into the R-4 tranny, (it stayed cool as the proverbial cucumber) but, the front drive shaft rotated when Jimmy was under tow and rear drive line was bolted up. (was locked in solid with rear drive line and couldn't rotate by hand, versus when in 2 wheel drive high, the front drive line does not turn when driving, but can be freely rotated by hand)

Any constructive input would be appreciated for enlightenment.
 

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