Flat-towing a full-size 4x4 pickup?

[SRath]

If anyone here has any tips or advice on flat-towing an '86 Chevy K20 4x4 with an identical '81 Chevy K20 4x4, I'd sure appreciate hearing it.



Both trucks have 350 motors, TH400 transmissions, NP208C t-cases and lockout front hubs. I have about 1900 miles to drive. The tow vehicle already has a factory oil cooler and I will be adding an auxilary transmission cooler to the very strong TH400 in it. Sadly, both pickups, though supposedly 8600 GVW 3/4 tons, have semi-floater rear axles rather than true full-floater Corporate 14-bolts, but that shouldn't make any difference unless there's a potential lubrication problem, should it? Both have factory lockers in the rear diffs as well.



I can remove the driveshaft(s) of the towed vehicle if necessary, but would need to plug the back of the slip-yoke NP208C t-case. I figure I can probably just unbolt the rear shaft from the the rearend and leave it in the t-case and just strap it securely off to the side under the truck (and tape the u-joint real well, of course), leaving it to plug the slip-yoke. With lockouts, I wouldn't think removing the front shaft would be necessary; just make sure they're in the "Unlocked/Free" position.



I have literally millions of miles experience with heavy loads and semis, but almost none flat-towing passenger vehicles. It isn't the potential hazards of towing, braking, etc that concern me, I'm well-versed in those, but I know some vehicles are not easily flat-towed due to problems with axle, t-case, and transmission lubricants not being circulated.



I'm a bullet-proof NP205 fan, and all I know for sure about an NP208C is that the fastest way to kill one is to starve it for lubricant and I'm pretty sure it relies on an internal pump running off the input shaft that would probably not be operating while being towed, which is why I lean towards removing the rear shaft. Right or wrong?



So what's the best transmission and t-case shifter positions for the towed vehicle? Neutral and neutral? Or neither; just remove the rear driveshaft? Should I unlock and bungee the steering wheel to the brake pedal so it turns with me but tracks straight? There are some details to get right and I don't want to learn the hard way by tearing anything up. I'll just be using a stout homebuilt A-frame towbar I picked up cheap and I'll make an equally stout matching base plate to fit the truck frame; no "clamp-on" bumper crap.



I know many of you RV guys flat-tow frequently, so hit me up with some do's and don'ts! Thanks!

 

[Hoefler]

Pull the drive shaft as you described, front hubs unlocked for sure. Transfer case and transmission park and in gear. DO NOT lock or tie the steering wheel! Let it rotate freely as the front wheels will track and self center as you drive. If you don't let it, the front tires will want to go there own way and fight you all the way and destroy your front tires. Make sure the front end is in alignment and will track straight when you let go of the steering wheel. Have a safe trip!

 

[NIsaacs]

Not knowing how the 208 lubes, I would just remove the drive shaft. Will the oil be high enough to leak out with the shaft removed?



I always left the steering wheel free. Just try not to turn real sharp or sometimes they will lock and not straighten out. Also try not to get in a position where you have to back up. The key is a towbar mounted with no slop and longer the better. Keep the towbar level.



The biggest problem I have had, is towing like for like, weight for weight. If the towed vehicle is smaller/lighter then the tow vehicle it works good. Like for like or smaller tow vehicle it can be scary at times:-laf



Sometimes light hookups are a pain.



Nick

 

[AClayton]

According to my Blue-Ox handbook, the 67 thru current Chevy pickup can be flat-towed behind a MH just by placing the Transfer case into nuetral and trans into park. The front hubs will need to be unlocked-whether they are manual or automatic.



I am unaware of any laws that state otherwise but as Nick stated... . it will be a much more pleasent tow when the tow vehicle outweighs the towed vehicle by at least a 1/3. However, with your driving experience and the fact that you are aware of that will give you the edge. Are you using a bumper style towbar?? I hate those things and never had much security in them... ... especially 1900 miles at Interstate speeds!



I wouldn't put much faith in those 14 bolt semi-floaters in your truck. They are about as reliable in a 3/4 ton truck as the 10 bolts are in a 1/2 ton. No 3/4 ton trucks should be sold with semi-floater axles... . junk! The Gov-locks in them will fail sooner than later also... ... . my College yrs will back that up!!! You put much bigger than a 33" tire on a 14 bolt semi-floater and use it off road it will be a recipe for disaster. Now the 14 bolt full-floater is a different story!!



BTW... ..... Blue-Ox is a vendor I use that manufacture tow-bars and baseplates for towing vehicles behind Motorhomes. I am certain you are aware that you need lights on the towed vehicle and of course, safety cables. Turn the key on to let the steering wheel unlock and remember that when re-fueling or stopping for the night... ... . that you cannot back up a towed vehicle!!





Alan

 

[mwilson]

I agree with Alan, transmission in Park, key to off not lock, and Transfer Case in Neutral with hubs unlocked. You can tow them a million miles that way.

As far as your lights go I am pretty sure that there is a plug-in / junction for the rear lights right by the steering column/firewall area. I would find an end at a junkyard that mates with it and make up a cord that would plug into your tow vehicle trailer connector and feed it in thru the grille or under the forward frame of the towed truck, then unplug the factory connector on the towed truck and plug yours in. That would give you all the rear lights and plate light which should be legal and adequate.

Easy Peasy, Brighty Lighties. Oo.



One great thing about that generation of GM trucks is there are acres of room under the hood to get at stuff. When I was younger and a lot more limber I used to sit inside the engine compartment on the inner fenders when I was working on the motors.

Now I wouldn't be able to get back out of there. :-laf

 

[HBarlow]

That trip you're planning is not one I would look forward to. 1900 miles on an interstate highway with an old truck wandering back and forth in the wind pushing and pulling, trying to swing your tow truck from side to side will not be much fun.

I don't know if they have the weight carrying capacity but a rented U-Haul tow dolly to dolly the front end of the towed pickup would surely make the journey a little easier.

 

[SRath]

Thanks guys, I knew you would have some answers for me.



I know the like-for-like towing setup is not ideal; but they are both pretty capable trucks. The tires on both are excellent, as are the brakes. The gearing is 4. 10 and the brakes and suspension on the front truck are extra-heavy duty (it's a Camper Special), so it will pull hard all day long. That old 350 Chevy and TH400 combo is as reliable as anything ever put on the road.



The 9 1/2 ring gear semi-floater rear axles will just have to survive until I get home where I have some real 10 1/2" full-floaters to replace them with. They aren't carrying any weight, so no big deal; but as Alan said: they don't even belong on a real pickup, imo. Both are technically "Corporate 14 bolts"; but like the pseudo 'dana 60' front axles in our dodges with their wimpy dana 44-sized axle shafts and lousy balljoints, the semi-floater is just a pretender compared to the real deal.



And Lord knows I have pulled thousands of sets of doubles over 1. 2 million miles, often in the worst weather Iowa can throw at you, so I have a near-phobia of ever driving into any place or situation I cannot drive out of and I know what not to do if having the tail wag the dog (or even pass the dog!) is not your idea of fun. :-laf



Trying to back up a set of doubles is like trying to push a length of chain. lol. I can do it straight, and have more than once backed the rear trailer into a dock on a bet, but it isn't easy and if you have to back around a corner, well, you're just pretty much screwed. The secret to backing doubles, btw, is all in the setup: get 'em straight & keep 'em straight or fail. They also need the heavier trailer in front; but occassionally someone calculates wrong (you can tell immediately and it won't make you happy) and nearly half of my doubles miles were with both trailers empty and equal -- which is the 2nd worst scenario on icy roads.



So I plan to load my tow pickup up with all the rust-free Dodge and older Chevy pickup parts and such that I can lay my hands on! That will add a little bit of weight to the front and help offset my massive fuel costs once I get home and sell them.



If I have any trouble, my brother can chase after me and use his diesel dodge to finish the job or, if I'm closer to home, my son or nephew can do the same with my diesel dodge and a trailer. Or sell the troublesome vehicle, or park it and fly back and get it or any number of things. I'm fairly handy with a wrench and know those trucks pretty well. Besides, I'm only a wireless connection and a few mouse clicks away from TDR!



I have planned a southern route away from the mountains and bad weather as much as possible (sorry CF, I'll have to bypass Colorado this time). The second truck is waiting for me at 4000 feet elevation in the california high desert. Interstate 8 is all downhill and then flat as a pancake for a very long ways from there. Luck was on my side there as its a pretty good climb from here to there! And I know not to get in a hurry. Steady and consistent is what eats up miles. Put in a good audio book CD and just cruise...



Like I said before, I will not even consider a bumper-mount tow setup and will build a stout frame-mounted baseplate to match the stout (and long) A-frame I bought made out of heavy-wall 2" square tube and 2" channel. The receiver hitch is class V, so that will all be well and good.



If I have any trouble with getting the towed pickup's lights to work with the front one's, I have a set of magnetic towing lights as backups.



All in all, I'm pretty durned good at the towing/hauling heavy end of things. It is the mechanics of driveshaft in or out; steering wheel free or bungee'd (I know not to lock it); etc that most concerned me.



I know the towbar should be level or maybe slope down just a little towards the tow vehicle to prevent the towed vehicle from trying to get underneath the front one in a hard-brake situation. Safety chains are all good.



The finicky Np208 t-case is the most worrisome thing and the best way to make sure it isn't a problem will probably be to just go ahead and remove the rear shaft.



I didn't know the famous Blue Ox towbar company had a "book" of what vehicles can be flat-towed and which ones need special treatment. That's pretty cool if it is reliable, Alan. That long list of chevy years includes at least 4 or 5 different t-cases, so I'm a bit skeptical. NP205, NP203, NP208C, NP241(?), maybe even a dana 20 way back when(?), and I have no idea what new chevy's have since I don't like new chevy's (which is ever since they abandoned live axles in front). Some of those t-cases are chain drive; some gear drive, one both; one full time; the rest part-time; etc. Saying "all from 67 to now" covers a mighty lot of different innards...



Harvey, I considered a tow dolly, but they really don't help with anything in this case that I can see. They just add weight to be towed. Same number of wheels on the ground. They would be great for a small front-wheel-drive towed vehicle, but I see no advantage to one here. And not all (many? any?) are built to handle a full-sized 4x4 pickup. If I were at home I would probably borrow a full-sized car hauler trailer and use my Cummins-powered truck, but that's not in the cards here. Flat-towing should work fine. As for the wandering, swaying, out of control road trip... well, I do own a Dodge, so I am all-too-well aquainted with extreme death wobble without even needing to tow anything...



For years, once a week like clockwork, an entire convoy of Mexicans would converge on a local auto auction place near home on auction night and would slap on some of the most questionable-looking generic towbars and hitches and head off to parts unknown down I-80 and I-35 with similar-sized cars pulling another. Upwards of twenty of them at a time. I always expected to eventually see them wrecked or broke down somewhere along the interstate, but never did, so it must work fairly well.

 

[NIsaacs]

Keep us posted on how the trip goes. With your writing skills it should be an interesting story. Not to mention some new experiences we can all learn from.



One good thing about Chevys, you can buy parts from Circle K stores



Seriously tho, if you should encounter a non repairable breakdown in Arizona, on the weekend, like you said I am only a click away. Good luck.



Nick

 

[AClayton]

Blue-Ox is a huge company and a very reliable source. There are exceptions to any rule but for the most part, any transfer case that has a nuetral setting can be flat towed. If the vehicle is auto, it goes in Park - manual, it goes in 2nd gear. Again, these are general rules of thumb and some foriegn vehicles can be an exception. But there are specific rules to follow if a manufacture states their vehicle can be towed four wheels down. Most vehicles that have a viscous clutch type transfer case can be towed four wheels down but NOT on a dolly.



I had a 99' Chevy before I purchased my 01' Dodge and towed it behind my old MH with no problems... ... ... . it had the 'autotrac' transfer case. it had a nuetral setting and therefore could be towed four wheels down. However, with a gas powered MH and the weight of a fullsize pickup behind me, the RV was very slow and got even worse mileage..... around 6mpg compared to 8mpg when I towed my X-wife's CRV.





With what I can recall, the 14bolt full-floater is a direct bolt-in. The full-floater is a bit bigger but a 4" lift can be installed and the driveshaft will fit perfectly. The driveshaft will bolt in but the slip-yoke will slide in way too far into the 208' when loaded to full GVW - OR full suspension compression on the trail!



Alan

 

[BLNRAY]

i have towed my 3500 dually many thousands of miles behind another 3500,while hauling fema trailers to fla and la. it is a much different tow than a trailer. you need a really good tow bar,i have a 10,000lb blue ox,any looseness in receiver or truck attach points will translate to road wander at high speed. your vehicles are pretty close in weight,i wood add some weight to the rear of the tow vehicle,unlike a trailer,noneof the flat towed truck weight is transfered to the tower. cornering can be trickie,your towed vehicle tends to want to go straight and has to be pulled around instead of following you. then there is the stopping. got brake hook up?

 

[Simplysmn]

I know alot of people don't like this site (uship.com) but look into it you might beable to save yourself a headache ?

 

[SRath]

Pulling doubles IS flat-towing, guys, (way beyond little pickup trucks) and if I were the least bit unsure or worried about being able to handle the driving aspect of this little trip, I would turn in my CDL and chalk 28 years of accident-free big rig driving up to nothing but dumb luck. I'm really not some weekend warrior wannabe behind the wheel, but thanks for thinking so.



I posted this because I wanted to make sure I didn't cause any inadvertant drivetrain damage to my towed vehicle by flat towing it since some vehicles can be damaged if certain precautions aren't taken. That's all.



Thanks for the tips on that aspect, guys! Catch ya on the flip-flop...

 

[NIsaacs]

????..... Now why did you go and ruin the thread by getting defensive? I didn't see where anyone questioned your big rig ability/experience. With your join date and post count you know you are going to get more advice then you ask for, thats a given. We are all guilty of getting off topic also



I will say that big rig doubles are somewhat different then two pickups going down the road with a towbar between them, the topic of this thread. The big truck is big, it is hauling about 25% of the net load on it's fifth wheel with about 75% on the remaining three trailer axles. Keeping in mind the second trailer is being towed with a fifth wheel mounted dolly not a tow bar. Also this total 5 axle combo has brakes on all axles. I know, you know all this. I also know you know the difference between this combo and the pickup combo. It's not the same. You will not have any "truck driving issues" with your trip.



Again, I ask you to post the story after the trip. I am interested in any type trucking, from 1/2 tons to 11 axle lowboys.



Nick

 

[Simplysmn]

Srath hope you have a safe trip and most of all have fun and enjoy the drive

 

[fest3er]

If you've ever pulled one or two old grain wagons behind a P/U or tractor, you'll be very familiar with the dynamics of dragging a P/U. As you said, you need rock-solid hitching. As someone else mentioned, be sure the towee's front end is fairly well aligned and fairly tight so it tracks straight. Make sure the axles are full-up with lube; you can drive many, many hours on old lube, with water in the lube, and with bad bearings. You can even drive a good distance on a failed bearing if you really had to, especially if you are going to pull the axles anyway.

You know how to drive. Just keep an ear, an eye, a foot and your nose on alert. You know how to see and hear. You might be surprised that odors can move forward, at what you can sense through your shoe.

People pilot less-capable rigs every hour of every day without trouble. You've covered what you reasonably can. The rest is adventure, often the only form of adventure we're allowed any more. For this trip, tweak your comfort zone so you can appreciate the adventure and maybe even enjoy it. Run outside your comfort zone, if you dare; how far outside is up to you.

 

[SRath]

I did get a bit defensive, didn't I? My apologies. It just sounded like the thread was heading into the "it can't or shouldn't be done" zone. It must be done, and I do plan to enjoy the trip, but I mostly need to just get home. I've been gone since September 11 and have missed everything back home with my boys, and you can never get that time back... But maybe once I get home with these two old, but rust-free, Chevy 4x4 beaters and toss each boy a set of keys, they'll forgive my extended absence (and maybe even give me my Cummins Dodge back?). You can't find good ol' trucks like these in this condition back home in the rust belt; certainly not for what I got them for here in the land of smog-it-or-junk-it, which was barely more than scrap price.



On that note, and to go well off-topic myself in explaining my motivation, I was sure thankful for modern technology (for a change) last night as I got to watch, on my computer and my brother's big-screen HDMI TV, my younger son and his state champion school jazz choir open the semi-final round of the state football playoffs with an absolutely stunning rendition of the National Anthem. I could both see and hear him! The broadcast commentators and the sports writers today even gushed over their performance!



I have never, ever got to see and hear him sing before. Not since grade school anyway. I always had to work... He was selected to that elite and tiny group of vocalists as an incoming freshman; which is nearly as unheard of as a freshman playing on their state champion varsity football team. Everyone always told me he was very, very good; now I have finally heard the proof. (he never sings at home or in the truck, believe it or not)



Then I got to watch his older brother's varsity football team whup the undefeated and top ranked team in the Class 3A state tournament. All via the miracle of live-streaming on the internet. The football team is going for a historic, never-been-done-before, 4th straight State Title after losing all their 'superstars' to graduation last spring and then being bumped up a class this season to boot. No school has ever won the Title the first season after being bumped up a class, either. This team intends to do both on Saturday in the Championship game.



I intend(ed) to be there, but it isn't looking likely now as this week progresses... but I'm sure going to try!