SIMPLE questions about towing 4-Down

[toolsonboard]

To address the debate around flat towing an e39 5 series BMW - it has a 5 speed ZF transmission that will be fine with flat towing. I've dragged an e36 3 series BMW more than 15k miles behind my class A without issue - it has the same clutch and trans. Baseplates are available for that vintage 3 series, and the subsequent e46 3 series cars through the model year when BMW started using 6 speed manuals (2003 iirc). I would not tow a 6 speed car - the internals of the trans require a lube pump internally to keep the tail shaft lubed.

[Mr_D]

Originally Posted by bamaboy473

That said, any manual tranny can be towed 4-down, just as it can be towed on a dolly.

Not true, there are some that are lubed only when the engine is running. Not many but it is possible.

[Gumpster808]

Originally Posted by Crasher

Where did you come up with that bit of information? I've been towing 4 down for 20 years and have backed up with all of them. I haven't backed up more than a hundred feet at a time, but have never damaged the toad alignment or the tow bar. It can be done safely if done with caution.

Not true in all cases. The installer that did mine said don’t try it.

He had an owner that decided to try and back up towing four down...busted the struts on both sides of the front end of the Toad.

[NeilV]

Originally Posted by DryCreek

I think that the advice to not back up is an old wive's tale that is faithfully passed down through the ages by folks who never had any experience flat towing vehicles.

Will the wheels spin to one direction and crab? Sure, if you take a big turn with the towing vehicle. How do you prevent that from happening? You start the engine and have someone inside the toad carefully moderating wheel turn. Oh no! It'll break their wrists - that's what you'll hear next from the ones who've never tried it. Why? Because that's what they've been told.

We grew up flat towing Jeeps and four-wheel flat wagons. You get used to their idiosyncrasies. My wife's family towed their Jeep to the Blue Ridge Mountains all the time. They learned how to be proficient at backing out of an unplanned situation too.

It can be done. It has been done. I will continue to be done as needed by many people who understand towing and have been doing it for a very long time. Just take it nice and slow, don't try to make a tight arc, keep the engine running to assist steering, and if you have a ready Brake system, disconnect the cable so that the brakes won't lock on you.

You just listed why the majority of people should not try to back up with a flat towed vehicle hooked up. Defeat the brake, put a second driver in the toad (which in many jurisdictions will be illegal) to start it up and steer it since it may not be humanly possible to overcome forcing the caster angles backwards and requires a level of expertise/experience many (probably most) may never be able to master.

[bamaboy473]

Originally Posted by screamingbir

Wow no wonder there are so many accidents on the roads.

Accidents happen for a number of reasons, often just surprise situations.

However, in cases where something new is being constructed, we like to reduce or limit the chances of accident by passing the concept by those that know.

[StubbyBus]

Originally Posted by pasdad1

I believe there might be a difference because with the front raised ....the transmission oil is not flat in the pan...it is sloped towards the back. Just something to consider....if the tilt is somehow keeping the trans lubricated more effectively than when It’s level.

Exactly what I was referring to. The output shaft bearings might be bathed with the front wheels up on a dolly where they might not be level for four flat. I know about neither case with the transmission in question, just something that is different between the two cases and in my mind invalidates the test on a dolly without further information.

[DryCreek]

Originally Posted by NeilV

1 - You just listed why the majority of people should not try to back up with a flat towed vehicle hooked up. Defeat the brake, put a second driver in the toad 2 - (which in many jurisdictions will be illegal) to start it up and steer it 3 - since it may not be humanly possible to overcome forcing the caster angles backwards and requires a level of expertise/experience many (probably most) may never be able to master.

1 - Why? It doesn't seem to be any more difficult than the regimen for preparing the Jeep to be towed four down. If someone isn't smart enough to partially undo what it takes to pull forward so that they can get out of a bind by going in reverse, then maybe they should not have a toad.

2 - So, you think that we're merrily backing down the interstate or some public roadway? That's about as silly an argument as I have found yet. We're talking about less than half a block in rare circumstances, a hundred feet in most.

3 - Do you mean like backing your vehicle into a parking space? What level of expertise or experience does that take? Maybe we just get a bunch more practice than most. All five of our vehicles are backed into their assigned spot - either under a carport or in one of the three garage bays. Heck, even both tractors are backed into the barn. You have to guide whatever implement is on the rear (normally a shredder) while keeping an eye on the bucket of the front end loader. I guess my wife, sons and myself are some sort of superhumans.....

[Crasher]

Originally Posted by DryCreek

1 - Why? It doesn't seem to be any more difficult than the regimen for preparing the Jeep to be towed four down. If someone isn't smart enough to partially undo what it takes to pull forward so that they can get out of a bind by going in reverse, then maybe they should not have a toad.

2 - So, you think that we're merrily backing down the interstate or some public roadway? That's about as silly an argument as I have found yet. We're talking about less than half a block in rare circumstances, a hundred feet in most.

3 - Do you mean like backing your vehicle into a parking space? What level of expertise or experience does that take? Maybe we just get a bunch more practice than most. All five of our vehicles are backed into their assigned spot - either under a carport or in one of the three garage bays. Heck, even both tractors are backed into the barn. You have to guide whatever implement is on the rear (normally a shredder) while keeping an eye on the bucket of the front end loader. I guess my wife, sons and myself are some sort of superhumans.....

I agree. Those of us who have had to back up a loaded hay wagon into a shed or maneuver a 40' field cultivator around irrigation drive units, or move a 12 row corn planter through town without clipping mail boxes or parked cars, have a different set of skills than the person who hasn't driven much more than a pickup. What seems second nature to some is impossible to others. Different backgrounds and life's experiences results in different skill levels.

[Reacher]

You're absolutely right Crusher. My tow bar manual says not to do it. So I don't. Hay wagons and and other farm equipment is no big deal but if you had a high dollar combine and the instructions said under no circumstances DO NOT BACK UP! Would you do it? If a freeway sign said WRONG WAY DO NOT ENTER would you see that as a challenge? just sayi'n

[bamaboy473]

OK, back to the re-design of the towing apparatus. Here is a fabrication to address two of the major concerns; a proper attaching point on the car, and safety chain attachment.
Look at what I'm thinking and give me your thoughts, please.

The safety chains will attach to a horseshoe that hangs below the plate.

I'm thinking of doing away with the Ready brake, and thinking of getting an in-car braking assist.

Is ReadyBrake or similar absolutely critical to have if we have safety chains?

[Crasher]

FWIW, my safety chains attach to a seperate plate that goes back to the base plate and not to the same plate that the tow bar attaches to. If your single plate fails, the safety chain won't do any good.

Any toad weighing over 3,000# must have braking assist by law and from a practical safety issue. Any internal brake assist is fine vs the readybrake.

[bamaboy473]

Originally Posted by Crasher

FWIW, my safety chains attach to a seperate plate that goes back to the base plate and not to the same plate that the tow bar attaches to. If your single plate fails, the safety chain won't do any good.

Any toad weighing over 3,000# must have braking assist by law and from a practical safety issue. Any internal brake assist is fine vs the readybrake.

I'm going to have to draw a pass on the attaching point for the chains, due to the design of the system. Nowhere to create a new installation point. That said, the ears coming out from behind the bumper are 1/2" x 2" x 6" welded inside a box arrangement, so I'll be comfortable that nothing will break.

The braking assist is just good sense and that will be installed in lieu of the Ready-Brake. Cable from ReadyBrake can't wind through the engine compartment, and going under isn't possible due to clearance.

The car weighs a bit over 3,000lb, but a question about the law....does it apply universally, whether a light-weight Class C gasser or a much heavier DP with air brakes?

[Crasher]

It does not matter what is towing it. Most states require auxiliary toad braking for any toad over 3,000#

[hohenwald48]

And most, if not all, require a breakaway system too.