[Jet-Black]

Hi Kids, this is grandpa calling. I am in a pickle and would appreciate your help.

I own a 2008 335XI 6 speed Manual Transmission with Sport and Cold Weather package. It is stock and I would not modify it for anything in the world, it is perfect for me as is. Well, I finally got a Motorhome; a Winnebago RV e-450 super duty with the famed Ford Triton V10 engine. My main questions are: Can I Flat Tow my BMW? Would the AWD system suffer? I am thinking it would not because all 4 wheels will be on the ground.

I know the manual says no, but it doesn’t make any reference to whether the car is Automatic or manual transmission.

I know mechanics, but have never worked on a BMW XI transfer case. My thinking is that it should be fine as all wheels would be on the ground.

Thank you for any advice/info you guys can share, I will appreciate it.

Grandpa!

[neilvan]

Its a general rule that if towing the wheels rolling on the ground shouldn't have axles driving them.

IF you are getting it towed a short distance to a shop you might get by but ya longer distances isnt an ideal; The awd system freaks out if the tires are a slightly different diameter even.

[Efthreeoh]

Flat roll towing with an automatic is not recommended because most automatics are lubed by the ATF fluid pump driven off the input shaft, which is engine driven. So basically the trans is not getting proper lubrication when being rolled-towed. Of course if you disconnect the driveshafts then it's okay. Find a lightweight aluminum trailer. Or get a Jeep or a Bronco, which have flat-tow modes.

[Jet-Black]

Thank you both I appreciate your input. I currently don't have enough money to buy another car just for Flat Towing. Even If I had, I don't have the room in my driveway for a 4th car as the RV is already taking half of it.
That's why I am inquiring about Flat Towing my 6MT. Does anyone have technical data so as to the transfer case inner works? I have been searching and can't find anything.

Thank you everyone.

[NikMN]

This is no different than putting car in neutral and coasting to an offramp or intersection. Obviously coasting usually lasts couple min at most and towing will be xx hours. But same principle applies. There is no pump to push oil in the gearbox or differentials just "power" input is reversed

This is my 2c so take it at your own risk.

[ppointer]

Tough for me to imagine the mods required to install the hardware needed for a flat tow hitch on your BMW. My money instead would go to an auto-specific flatbed trailer. They’re not too expensive, as I have looked into them for towing my Z3M.

[Jet-Black]

@NikMN - I am in TC BTW.
I agree with you, Mechanically speaking, with the transmission in neutral, my thinking is that the transfer case should be fine so long no electronics are running and requesting or sending "signals/instructions" from the sensors in the wheels. However, I would like to know if there is anything else I am missing or should be aware off.

ppointer - I also agree with you. It would require modifying a front tow plate and bolt it to the front frame. Luckily our cars do have bolt it frame face. That possibility is what makes me inquire about the transfercase, otherwise i would not even research it. getting a Trailer is brings me back to the same reason I can't buy a Tow vehicle. Money and Space to storage it afterwards.

[Bmw1939]

I'm sorry grandpa but you are going to have to rent a 4 wheel tow dolly. You could buy one, but I know you have some space issues.

[marvinstockman]

I agree with 1939, a four-wheel tow dolly is the way to go

[Efthreeoh]

Originally Posted by Jet-Black

Thank you both I appreciate your input. I currently don't have enough money to buy another car just for Flat Towing. Even If I had, I don't have the room in my driveway for a 4th car as the RV is already taking half of it.
That's why I am inquiring about Flat Towing my 6MT. Does anyone have technical data so as to the transfer case inner works? I have been searching and can't find anything.

Thank you everyone.

Apologies Pops (we're probably near the same age - Lol), I didn't see that your car is a manual transmission. I change my answer to I don't think it would harm the transfercase since it is electronically activated, but does your car have a locking steering column? I think BMW dropped the steering column lock in 2010, but I'm not sure. That needs some research on your part. When you turn off the car and remove the key, does the column lock. I'd be concerned towing with the front wheels lock in a non-straight position.

[gbalthrop]

Would you tow a 4,000 lb. Trailer with NO brakes on the trailer?
How far, & at what speeds do you intend to go?
Where do you intend to go with the 335xi that you can't go with Winnebago?
HOW/WHERE would you attach Tow Bar to 335xi?

I'd "pick one" and NOT risk damaging BOTH. (But that's just ME)
George

[Brian86]

I'm on team 'get a trailer'. Flat towing cars is super sketchy. Put it in a cheap outdoor self-storage spot when not in use.

Note @Efthreeoh above about the steering lock. Take heed.

T-case will be fine. It's being rotated by the front axle and lubricated. Default 'car not running' position for the T-case is disengaged.

I'm not sure it's safe for the transmission. Maybe somebody that has actually done it can say otherwise.

The issue with the transmission is the output shaft is up top and dry, the transfer shaft is on the bottom in the pool of gear oil. Output shaft will be spinning at road speed driven by the rear axle. Transfer shaft will NOT be spinning. No oil is moved from the pool at the bottom to the top to lubricate the bearings on the upper output shaft.

If the internal layout of the box has some of the syncho sets on the transfer shaft, then those gears will be spinning on the lower transfer shaft, which will move gear oil up top.... will those gears move enough oil up top to distribute it to all the bearings, I don't really know.

[jsunma]

Originally Posted by gbalthrop

Would you tow a 4,000 lb. Trailer with NO brakes on the trailer?
How far, & at what speeds do you intend to go?
Where do you intend to go with the 335xi that you can't go with Winnebago?
HOW/WHERE would you attach Tow Bar to 335xi?

I'd "pick one" and NOT risk damaging BOTH. (But that's just ME)
George

I'm totally with George on this one. Will you really need to have your BMW with you as you drive your RV around? Unless you are going totally on the road (i.e., you no longer have an address where you will return to and/or can garage the car), is it really worth your while to deal with buying/towing a trailer, attaching a hitch, and/or no matter what scouring your car by having it towed behind your RV?

[krhodes1]

Originally Posted by jsunma

I'm totally with George on this one. Will you really need to have your BMW with you as you drive your RV around? Unless you are going totally on the road (i.e., you no longer have an address where you will return to and/or can garage the car), is it really worth your while to deal with buying/towing a trailer, attaching a hitch, and/or no matter what scouring your car by having it towed behind your RV?

As one who RV'd with his folks as a kid, not having a "toad" is a HUGE PITA if you have an RV big enough to comfortably tow one. When you get where you are going and setup, the LAST thing you want to do is move the thing. HUGE PITA to pack up, disconnect everything, and go somewhere just because you need to get groceries or whatever. You don't want to move the RV unless you absolutely have to.

With a manual, I would just do it. In an ideal world, I too would get a trailer, but if you don't have the means, you do what you need to do. I don't think it will hurt a thing.

[e90yyc]

Originally Posted by krhodes1

As one who RV'd with his folks as a kid, not having a "toad" is a HUGE PITA if you have an RV big enough to comfortably tow one. When you get where you are going and setup, the LAST thing you want to do is move the thing. HUGE PITA to pack up, disconnect everything, and go somewhere just because you need to get groceries or whatever. You don't want to move the RV unless you absolutely have to.

With a manual, I would just do it. In an ideal world, I too would get a trailer, but if you don't have the means, you do what you need to do. I don't think it will hurt a thing.

Like my grandpa used to say: If you don’t have a toad you’re a total chode.

[Jet-Black]

Thank you everyone for your answers and insights. I appreciate them all.

My daughter decided that I can add a tow plate to her car so I take hers when I go camping. Obviously, she will be getting my 335 for that time. I would like to call this a Win-Win, but wonder if I will need new tires when I get my car back.

I truly appreciate all your comments. You guys are a great bunch.

Grandpa.