Towing on a cross country roadtrip

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TooManyIdeas
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Towing on a cross country roadtrip

#1

Post by TooManyIdeas » 14 years ago

I recently bought my 720 and have heard that it can tow 6000lbs. Since I have no further use for my old truck I'm going to give it to my Step Dad. I was planning on dollying it from Albuquerque NM (where I live now) to Philadelphia PA (where my parents live) this x-mas. It’s about 2000 miles. Am I nuts or can the 720 do it? Also The OD reads 98,000 miles so I was wondering about any pre 100k maintenance that may need done before the trip.
82 Datsun 720 King Cab Diesel - FOR SALE !!!!
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asavage
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Re: Towing on a cross country roadtrip

#2

Post by asavage » 14 years ago

TooManyIdeas wrote:I recently bought my 720 and have heard that it can tow 6000lbs.
:shock:
?????
Since I have no further use for my old truck . . .
What is the make/model of that truck?
Am I nuts or can the 720 do it?
Likely, yes!
Also The OD reads 98,000 miles so I was wondering about any pre 100k maintenance that may need done before the trip.
I'm not thinking of anything other than the usual: change the transmission oil!. Fuel filter on schedule, of course. Wheel brgs if you don't know how long it's been since they've been done. Alternator brushes are easy to check, and when they get worn they can damage the (expensive) rotor -- it's unique to the diesel version.

==============

I do a fair amount of vehicle towing (see these pics, the last pic in this post (that's about 6000 lbs, trailer & junk truck combined), and some of these pics), and I don't think that 61 HP is enough to reasonably & safely pull more than about 1500 lbs. And the brakes are definitely NOT up to towing more than 2000 lbs, IMO. If your dolly has its own brakes, you *might* get away with 3000 towing with a small pickup, but even that's pushing it.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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asavage
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#3

Post by asavage » 14 years ago

When towing an un-braked load (trailer, dolly, whatever), it's a good idea to keep the weight ratio at 1000 lbs more on the towing vehicle than the load. If the load has its own brakes, the ratio can go the other way, depending upon the number of towed axles.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

redmondjp
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#4

Post by redmondjp » 14 years ago

Towing that much weight with a truck that weighs under 3K lbs. is a very bad idea IMO. When your trailer weighs much more than the towing vehicle, it's easy for the trailer to push the back of your vehicle sideways, and really bad things happen if trailer tongue starts oscillating side-to-side. Trailer brakes would be a must, and they must be operating correctly as well (this is not a given--a lot of people seem to ignore maintenance on their trailers until one of the wheels falls off while they're on the freeway somewhere . . .).

A couple of months ago I used my 720 to tow a LIGHT flatbed trailer (used for moving riding lawn tractors) with a medium-sized upright piano on it. I'd guesstimate that the trailer and load together weighed 1000-1100 lbs.

Had to go up some fairly steep hills--was only able to do about 20 mph max, in a 35 zone. Braking, well, the brakes aren't that super to begin with. I'm glad that I only had to go a few miles across town. I definitely wouldn't use this truck to tow anything heavier than what I did, especially if I was out on the highways.

This towing experience made me really appreciate the towing capabilities of my '79 Chevy 3/4T 4x4, which can handle a twin-axle flatbed trailer with a 4K lb. car on it with no problems (and it's not scary to tow with unless the weight is unequally distributed on the trailer with more being behind the trailer's axles--then watch out!). But this truck weighs in at over 6K lbs. and gets 9 mpg at best, so it only gets driven when I need to haul something big and/or heavy.
1982 Datsun 720 King Cab, SD22, 86K miles (sold)
1981 Rabbit LS 4-door, 1.6D, 130K miles (sold)
1996 Passat TDI 4-door sedan, 197K miles

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TooManyIdeas
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#5

Post by TooManyIdeas » 14 years ago

The truck being towed is a 1990 toyota pickup 2wd about 2500lbs. The dolly was only going to be one of those 2 wheel uhaul jobs. So you guys think it would be that bad of an idea

oh as for changing the fluids, I know in gassers its a bad idea to switch to synthetic after about 50k miles is this true for diesels as well?
82 Datsun 720 King Cab Diesel - FOR SALE !!!!
85 Chevy Monte Carlo CL
90 Toyota Pickup -SOLD
05 Kia Spectra 5
02 Dodge Dakota Quadcab
-OOOOOOOOHHHHHHHHH YEAH!!!!!

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#6

Post by glenlloyd » 14 years ago

TooManyIdeas wrote:The truck being towed is a 1990 toyota pickup 2wd about 2500lbs. The dolly was only going to be one of those 2 wheel uhaul jobs. So you guys think it would be that bad of an idea

oh as for changing the fluids, I know in gassers its a bad idea to switch to synthetic after about 50k miles is this true for diesels as well?
I switched to synthetic in my Dodge B250 at 170k miles...no problems. I recommend switching to synthetic for most vehicles, except Mazda RX-7's of course.

I also can voice my appreciation for a large tow vehicle. I don't use the Dodge much anymore EXCEPT for going and fetching vehicles. There's nothing like it for towing.

my .02

sa
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Re: Towing on a cross country roadtrip

#7

Post by kassim503 » 14 years ago

TooManyIdeas wrote: Also The OD reads 98,000 miles so I was wondering about any pre 100k maintenance that may need done before the trip.

I would certainly change out the trans fluid/gear oil with some high quality synthetic, especially if you are going to do the tow. I switched to synth on my maxima at 170k miles and didnt have a problem.

Also I would change out the diff fluid with synth as well, usually the differential is forgotton and the fluid resembles molasses.

I would say itll be ok if you drove the trip, even tho its really dicey and you would have to play nice (especially on the hills in PA), and you have a great chance of some kind of brake boil over when going down the hills on the east coast, but I guess with the proper downshifting and whatever its doable, just dont lose the brakes. Also you would probably go really slow up the hills as well, but traffic can wait and if you dont stall it out it dosent matter :D

I had a towing mishap back in the day when I used to race circle track at the local racetrack (now cars just rot on my driveway). I had a 86 ranger towing a car carrier w/ a car, could be chevy caprice I dont remember but it was heavy enough for me to lose control on a turn (I had it coming), good thing I wasnt going fast and all I did was bend the bumper, bed, tailgate and crack the tounge on the trailer. So mistakes do happen and it sucks when it does.


Do you have a good friend with a full size pickup? I would rather tow with that and pay him/her for the time you have the truck, and let him/her drive your truck in the time being. Full size pickups tow so much better than compact pickups.
'83 maxima sedan, l24e, a/t, black

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asavage
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#8

Post by asavage » 14 years ago

TooManyIdeas wrote:The truck being towed is a 1990 toyota pickup 2wd about 2500lbs.
I thought that was wrong, but it turns out you're right: 2560 lbs.
The dolly was only going to be one of those 2 wheel uhaul jobs.
I own one. They weigh 400lbs or so (without brakes). Mine is rated for 3350 llbs "towed weight" (including weight of dolly), so I assume yours will be within spec for the dolly itself.
So you guys think it would be that bad of an idea
If you try to rent it from U-Haul . . .

You've seen the shorty '89 Aero I drive (in the pics I linked to upthread). Years ago, I used to be able to rent U-Haul's 6'x12' covered trailer, and I used to rent it about twice a year to move things covered.

Then in about 1999 or 2000, they refused to rent it to me anymore. Why? When you rent a trailer from U-Haul, they want to know what's going to tow the trailer, and they get sort of specific. About 2000 they decided that the GVW of the 6x12' trailer was too high a percentage of the combined weight. Never mind that I might be carrying a trailerfull of styrofoam: from U-Haul's perspective, I might be loading a trailerfull of broken sidewalk.

So, for a while, I rented the 5'x10' covered trailer instead. Then I got sneaky and just told them that I had the "long" version of the Aero, which is something like 200 lbs heavier, and now they don't bug me anymore. I could also have told them it's the 4WD version, which would work as well.

'Nuther story: In Feb-1981 I towed a 1959 Cadillac Eldorado/Seville (a rare combination model, one of only 975 made) from Phoenix to Seattle. The trick is, I towed it behind a 1973 Volvo 145 Wagon. I was young and very stupid. I have a pic somewhere buried of that combination. I have a couple of harrowing tales of the three days drive it took me to get to the PNW. Summary: I wouldn't do it again on a bet. I could have died several times, I used up a decade's worth of luck. So, when you ask . . .
So you guys think it would be that bad of an idea
I'd have to say, Yes, I think that the 720 diesel PU does not have enough margin in both the pulling and braking depts. to safely pull 3000 lbs 2000 miles in the dead of winter.

I'm not saying it can't be done -- I've proven that it can. But an older, wiser Al has to say that it wasn't one of my best decisions, even if I got away with it.
I know in gassers its a bad idea to switch to synthetic after about 50k miles is this true for diesels as well?
You are mistaken about the "bad idea" part as well.

Back in the bad old days of Mobil 1's debut (circa 1974?), shaft seal technology in automotive engines was still at the point where a good many of them were "rope" seals (really), and the rest were pre-elastomer technology that depended upon light aromatics attacking them and keeping them pliable. It was possible, therefore, to have a problem when switching to a synthetic oil that didn't have all the light aromatics, because "rubber" seals could harden without that crap in the oil, and rope seals didn't have enough heavy crap in the oil to keep them plugged. So started the "don't switch to synth. on an old engine" reasoning -- and it made sense, say pre-1980.

Engine seals are constructed of entirely different materials now. While modern seals can still harden, they do not depend upon the lube oil to keep them pliable. "Rope" seals are long history. And some synthetics even have plastisizing agents to try to keep seals pliable (this is not unique to synths: "high-mileage" oil blends are primarily STP-like polymers and seal swell agents added to regular base stocks).

The other arguement you'll sometimes hear is that the synthetic oil will "clean out" the gunk in your engine and Bad Things will happen.

1) Synthetic (or other "detergent") oil will not clean out accumlated gunk. It is not a "cleansing" fluid. The term detergent in the tribology sense does not refer to cleansing action, but to additives and properties the tend to reduce the suspended crud in the oil from adhering to the metallic internal parts. IOW, the rate at which crap will build up on the inside of your engine will be drastically reduced, but existing crap will not be magically (or otherwise) cleansed away. Remember this: oil detergent additives are not like Tide.

2) If your engine has so much gunk that great sheets of it can come loose and clog some vital orifice, you don't have an engine that's going to be around for a great long while anyway.

The SD is old-tech, even for its day. However, I'm confident that switching to synthetic lubes everywhere on your 720 is a good choice, and that's what I did to mine.

All the foregoing was engine-related. Transmissions, diffs, and chassis components (as well as brakes: don't forget DOT5/synthetic brake fluid) have no problem with synthetic switchover. In the case of the trans, being as there is a known weak area (the front brgs, read the FS5W71b thread), my opinion is that synthetic lubricant is the only sane choice for that transmission.

Chassis lube is often neglected too. Pump the grease in and flush out contaminants, esp. the idler arm. Grease is cheap, ball joints aren't.

Clutch fluid and brake fluid: DOT3 fluid is hygroscopic (is miscible and attracts water) and should be flushed/replaced every two-four years. Usually doesn't happen, of course. I flush DOT5 fluid through, which is non-miscible and doesn't attract moisture (and is actually a lubricant to boot, which DOT3 isn't), plus it has a much higher boiling point, in case that ever becomes a concern -- such as towing.

The clutch fluid should be changed too.

If you switch to DOT5, you really do need to try to remove as much of the old fluid as possible. I budget two quarts of DOT5 when I switch a vehicle over. Yeah, you throw a lot of it away, but it's cheap insurance against for a good job.

Std. coolants are only good for two years/30k miles, and then the corrosion inhibitors (primarily silicates) die off and your expensive oil-to-water heat exchanger starts getting eaten up. So change the coolant too.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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philip
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Re: Towing on a cross country roadtrip

#9

Post by philip » 14 years ago

TooManyIdeas wrote:I recently bought my 720 and have heard that it can tow 6000lbs. Since I have no further use for my old truck I'm going to give it to my Step Dad. I was planning on dollying it from Albuquerque NM (where I live now) to Philadelphia PA (where my parents live) this x-mas. It’s about 2000 miles. Am I nuts or can the 720 do it? Also The OD reads 98,000 miles so I was wondering about any pre 100k maintenance that may need done before the trip.
Completely nuts.

I had an estimated 1300-1400 lbs payload in my truck once ... Beatty, NV (north-east of Death Valley) to Los Angeles. Plenty of mountain passes. The power was barely adequate and the BRAKES were not. The truck weighs about 2850.
Image

Here's a handy guide to matching towing vehiles to hitches, trailers, and weight limits.
Reese Trailer Hitch tables

Suggest also that you call a U-Haul dealer for hitch class and maximum weight information for such a light duty truck. 720 2wd are essentially the same through 1986 for comparison.
Last edited by philip 14 years ago, edited 2 times in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

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philip
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#10

Post by philip » 14 years ago

asavage wrote:snip-
Clutch fluid and brake fluid: DOT3 fluid is hygroscopic (is miscible and attracts water) and should be flushed/replaced every two-four years. Usually doesn't happen, of course. I flush DOT5 fluid through, which is non-miscible and doesn't attract moisture (and is actually a lubricant to boot, which DOT3 isn't), plus it has a much higher boiling point, in case that ever becomes a concern -- such as towing.
I learned a different lesson from a DOT 5 experience. This was in a Ford Ranger. I thought I'd be "smart" by replacing the 3 yr old Dot3 by simply bleeding all four corners. Well ... two years later a caliper started leaking fluid. So I tore everything down and discovered that:

DOT 5 will not suspend water so ... ALL water finds its way to the lowest points in the system.
The bleed screws are NOT in the lowest points in the system
So ... there was solid RUST at the lowest points in the caliper bores AND wheel cylinders which resulted in piston seal damage.

So I do not suggest changing to DOT 5 unless you are doing a full brake system overhaul.
Last edited by philip 13 years ago, edited 1 time in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

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#11

Post by asavage » 14 years ago

With DOT3, the water is suspended. I run quite a bit of DOT5 in behind the DOT3, and am confident that little DOT3 is left in the system.

After conversion, water should not be introduced to the system. If water *is* introduced, that's not a fluid spec problem.

I live in what is probably the wettest part of the US. I have not touched the hydraulics on this van since 1999. (I'm on my second set of rotors and I've turned them four times, but I haven't touched the hydraulics).

Water-in-brake-fluid is definitely a problem with DOT5 -- there was some kind of TSB-like thing issued about DOT5 and a GA airplane -- IIRC, water ran off the cowl and directly onto the brake reservoir vent, which was not a conventional sealed vent as is common today. Once water got in, it quickly made its way to the lowest point, and corrosion was the result.

But that's not a fluid problem, IMO. YMMV.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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TooManyIdeas
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#12

Post by TooManyIdeas » 14 years ago

I was hoping you guys would say otherwise. That puts a damper on my plans. oh well. Not saying I'm going to do this all at once but If I upgraded the brakes say with Hydroboost, and added a propane kit (company claims 80hp cooler egt and better mpg), maybe even a turbo down the line would I be able to pull off this trip. Or is this truck not able to pull it off reguardless.
82 Datsun 720 King Cab Diesel - FOR SALE !!!!
85 Chevy Monte Carlo CL
90 Toyota Pickup -SOLD
05 Kia Spectra 5
02 Dodge Dakota Quadcab
-OOOOOOOOHHHHHHHHH YEAH!!!!!

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asavage
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#13

Post by asavage » 14 years ago

TooManyIdeas wrote:If I upgraded the brakes say with Hydroboost,
That won't increase the swept area of the pads & shoes. That's not an upgrade that is any good for towing more weight.
. . . and added a propane kit (company claims 80hp cooler egt and better mpg)
No.
maybe even a turbo down the line would I be able to pull off this trip. Or is this truck not able to pull it off regardless.
If it was a summer trip and completely on the flat, towing 3000 lbs, and with a dolly with surge brakes, I would maybe say that it's not a completely nuts idea. But in winter, hilly route . . . it's just way too marginal.

And I seriously doubt you will be able to rent a surge-brake tow dolly if you tell them what you're going to tow with a 720 -- gas OR diesel.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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philip
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#14

Post by philip » 14 years ago

TooManyIdeas wrote: I was hoping you guys would say otherwise. That puts a damper on my plans. oh well. Not saying I'm going to do this all at once but If I upgraded the brakes say with Hydroboost, and added a propane kit (company claims 80hp cooler egt and better mpg), maybe even a turbo down the line would I be able to pull off this trip. Or is this truck not able to pull it off reguardless.
TooMuchImagination: Forget it. You'd be mucho money ahead to pay someone to drive the Toyota out and then pay their plane ticket home. Or, ever hear of Auto DriveAway?
Last edited by philip 13 years ago, edited 1 time in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

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philip
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#15

Post by philip » 14 years ago

asavage wrote:When towing an un-braked load (trailer, dolly, whatever), it's a good idea to keep the weight ratio at 1000 lbs more on the towing vehicle than the load. If the load has its own brakes, the ratio can go the other way, depending upon the number of towed axles.
Reminds me of the time (actually twice) when I tow-barred a '74 Toyota Landcruiser (est 4200 lbs) from Indio back to Anaheim (90 miles) using an '84 Ford Ranger (est 2900 lbs).

There was NO WAY I could make a right turn as the Toyota would push the Ford sideways. WIDE lefts could be made. The immediate solution was 50psi in the Toyota's front tires and 25psi in the Ford's rear tires.

STOPPING was a white knuckler!
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

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