How far can you flat tow an auto trans before...

My pickup went by-by today. Had a tear in my eye as I was counting the $100 bills.
Tomorrow night I'm picking up my "new" car. My 39 Plymouth has a newer Mopar drive train with an auto in it. I have to tow it home on a two wheel dolly, about 30 miles, give or take. Its suppose to be cold (below zero), it will be dark, and I'm getting fat and lazy. Do I need to pull the driveshaft? Will the 30 miles be enough to screw up the trans? That would piss me off.

If I do pull the driveshaft, what do I do toplug the tailshaft hole so ATF doesn't run out? Don't have much experance with the dollys, always used trailers before.

Pictures: Yes boys-n-girls, that is suppose to be factory black paint! The car is a low miles Arizona body. Comes with all the paper work, the motor starts with a turn of the key. I can't wait to get it home and strart screwing it up. Gene
Gene

 

Gene,
You have to remove the driveshaft before you flat tow, or your gonna be real pissed at yourself because the trans WILL be trashed.

 

Hey, I just towed a pickup with an automatic about 70 miles, I just took the driveshaft loose at the rearend yoke, left it plugged in the tranny, pulled it over to the frame and tied it off with a rope, just tie it secure where it won't vibrate out of tranny. I checked it once, worked for me........with no trans fluid coming out..................

 

Back it on the dollie, tie the steering wheel.

 

If it runs, could you maybe leave it running in neutral, as long as your not going that far?

 

Back in the day when our race car had an automatic in it, we just pulled the drive shaft and threw it in the back. I don't remember fluid coming out, but it was an early 3 speed Ford-o-matic and it may be different. Anyhow, I would pull the drive shaft loose from the rear end at least and tape up the U-joint parts real good.

 

The car has no exhaust past the mainfolds so I don't think I want to let it run. The steering column is only bolted to the dash with one bolt right now, so loading it backwards probably wouldn't be a good plan either. Guess I better drop the drive shaft. Crap.

Oh well, at least I will have it home.
Gene

 

Gene -if that drivetrain is 70's or newer, you can just load it up and drive.
I have towed many cars on a Dolly up to 500 miles with no problems.
I think the misconception that it ruins a trans is cause it used to always be the case with the early models.
I towed my A Roadster down to the drags last Aug on my dolly -6-1/2 hrs one way.......and after I broke an axle I loaded it on my Bros rollback and towed his T coupe BACK HOME....same deal!
I will say this- NEVER tow one with the motor end of car you are towing on the ground.
It will whip and sway till you stop and reverse it!

 

He's right with the older style pumps this would have been a problem but with a newer 70's transmission you should be ok. Somethign about pump pressures and the governor but think about how many cars you've seen being towed by tow trucks or whell lifts. Have you ever known one driver to pull the driveshaft before he towed it?
Besides 30 miles isn't all that far yo can pull it out for piece of mind sakes but I don't believe it's really necessary.

 

People with big RV's have the same situation. They don't pull out and put back in the driveshaft everytime they tow their cars.

 

I wouldnt be towin it without pulling the driveshaft. It is one of those things that can change so much from year to year to model to model that for the amount of effort it takes to take out a driveshaft just have the piece of mind. Even if you have to take the shaft right out and let the fluid drain would you rather buy 20$ worth of tranny fluid or 200$ worth of tranny? As for how often do you see a towing company disconnect a driveshaft. I see it at least 5 times a week when we get pickups towed into the shop. It really isnt worth the risk if you dont know for sure.
Just my $0.02

 

Thats why you see so many Saterns behind RVs. You can flat tow them no problem.

 

The trans in this thing is a late 80s or early 90s. It might be an overdrive auto. This aint no $200 trans. Gene

 

dont know the cut off year but the reason you couldn't flat tow earlier automatic cars is they had 2 pumps in them and the rear pump would work if it was towed with the wheels on the pavement.You could push start these cars but you needed to get them up to around 30 before the pump put out enough pressure to turn over the engine.My dad used to start cars this way alot I think your safe on anything newer than 70the rear pumps were done away with in earlie 60s

 

looks a lot like my wife's old 39 plymouth...is the black paint brushed on?

 

It's all a matter of lubricating the output gearset and planetary on most auto transmissions. A few of the older auto transmissions did have front and rear pumps, the rear pump could provide some lube pressure to keep everything cool. I can't say for sure about that MOPAR trans but our GM stuff most of the FRONT wheel drive stuff can be flat towed without a problem but the rear drive stuff is a no-no. A couple of months ago we took apart an SUV that was flat towed and we almost had to torch it to get it apart, from the middle of the trans to the output shaft was welded together from the heat/lack of lube. Now I heard that if you overfill the trans and dolly it with the nose really high that enough fluid will flood the back end of the trans to keep things from getting toasty. Just my nickle.

 

here's a pic, same primer spot on the fender, and red primer showing thru....

 

i would be safe and unbolt the shaft and strap it up to the frame rail after taping the caps up good with duct tape.

 

From someone who knows transmissions, especially MoPar ones... pull the driveshaft. Tie it off to the frame as mentioned earlier to keep the yoke in to prevent fluid loss.

The problem with backdriving any transmission (usually caused by towing) is the lack of lubrication. It doesn't matter whether it is a stick or an automatic.

How long would you spin an engine over without any oil in it?

 

i have towed many cars with no problem but we usualy dont pull them to fast

 

That thing is definitely sweet lookin......needs a little off the top though.

 

Unhook the driveshaft. I learned that the hard way using a tow dolly to get my 65 imala ss back home. The powerglide blew up after about 3 miles. I had to pay for the rebuild then twice at about 5oo-600 bucks a pop... I learned an expensive lesson. Don't take the chance. Unhook it.

 

The old powerglides had a rear pump and it circulated the whole time you were towing if you didn't drop the drive shaft. I'm thinking that some of the other autos had the same setup.
Once the rear pump was gone it didn't make any difference; it is a good idea to tow in neurtral. Trust me before the rollback became popular you didn't see the tow jockey crawling under everyone's car and dropping the drive shaft. They just hooked up and towed.

I've towed autos long distances at highway speeds no problem. I wouldn't worry about a 30 mile tow.

 

I can't say whether or not to pull the driveshaft, but when we towed my '62 Thunderbird we did, and to plug the tailshaft we cut the bottom off a 20 oz. coke bottle, slipped it over the end and duct taped it on. Worked great for 1000 miles.

 

Big Daddy31 towed the galaxie from here to houstin, I'm not sure why it would have been cheaper to fly in a drive it home, but...
anyway I degress, I don't think he pulled the drive shaft, got home and started driveing it. he may still be driveing it, at least I hope so.

 

WATCH that the tow dolly fenders do not cave in
the CAR fenders when you make a turn!


No need to ask how I know.

 

a few more pics....we sold it to a guy named Larry Isenberger, in Mesa, in April or May 1998. I'd be very surprised if it's not the same car....

 

Didnt mean any offence with the dollar number just trying to put the idea in perspective that its better safe than sorry.

 

I know the 60's Mopar autos have a front and rear pump, so flat towing was not an issue. You could even push start those models.

 

here are the last 3 pics we took of the car, when we sold it.

I guess the body is nice by IL standards, but it was dented up, had been sandblasted and brush painted, and had some holes in the floor fixed with brazed in flat metal patches, as I recall. We pulled the 6 out and I set in the junkyard 318, then later took it out for use in another car, and sold the car without the motor.