Flat towing an ix

[ForcedFirebird]

Rad! Glad it worked out. :)

[Kershaw]

It was fine! I took 2nd place in my class and 3rd (or 4th depending on how you calculate it) overall out of 62 competitors.

[nando]

It will be fine.

[Kershaw]

I'm going to give flat towing a shot. If this doesn't work out, maybe I'll use a dolly and remove the front guibo.

The plan, based on the points put forth here, is to have the engine off, trans in neutral, steering unlocked, and hope for the best. Lol.

[The Dark Side of Will]

How does it turn any gears? That makes no sense. The input shaft is moving at idle, but the gears arent doing anything. Or are you telling me that sitting at idle in neutral all the gears are moving? Come on..

Bro, do you even transmission?

Idling in neutral (manual trans, as noted), the input shaft turns the countershaft, which turns all the shifted gears, which ride on the output shaft. The only part that isn't turning is the output shaft.

It's different in an automatic... but for an automatic, as long as the pump is turning, the transmission will be basically ok. 4HP22/24's don't like to be revved in neutral, though.

[2002tiiguy]

and besides, with the transmission in neutral, theres no load on anything, you could probably flat tow a car in neutral with no oil in the transmission a long distance before it caused any real damage, someone hook up the output of a g260 to a motor and leave it spin for a month, lemme know the results

[2002tiiguy]

just flat tow it in 5th, that way when you get there, you dont have to worry about a dry startup without oil pressure, also keeps the battery charged, runs power steering, and if you turn on the ac, it keeps your beer cold in the footwells

[Kershaw]

Aside from the thought experiment, I have friends that have flat towed their race cars for many years over many miles with 0 issues. Granted they are RWD....

That's great to know. Thank you. The transmissions are identical internally.

[jeenyus]

How does it turn any gears? That makes no sense. The input shaft is moving at idle, but the gears arent doing anything. Or are you telling me that sitting at idle in neutral all the gears are moving? Come on..

This.

I towed mine for about 10 miles in the city and there was no issue. I'd say my brakes took all the beating in that towing cause you gotta keep yourself from smashing into the car towing you.

If the car is in neutral, it's not utilizing the gearing.

[nando]

The output shaft is turning in a flat tow situation.

That means that all the needle bearings where the 1st, 2nd, 3rd & 5th gears ride on the output shaft are turning, but there aren't any gears turning to get the oil moving, so there's basically no lubrication for those needles. Oh yeah, and the pilot bearing/bushing where the output shaft centers in the back of the input shaft.

Also, coasting down a hill with the engine running turns all the gears and gets oil moving.

Tie the clutch pedal down and put the trans in 5th could work.

How does it turn any gears? That makes no sense. The input shaft is moving at idle, but the gears arent doing anything. Or are you telling me that sitting at idle in neutral all the gears are moving? Come on..

[ForcedFirebird]

Understanding the argument of fluid, we are talking about a Getrag here. The fill level is only slightly below the center of the on/out put shafts an under hard braking, it will actually spit fluid out of the vent hole in a running condition. Perhaps if it were being towed static on a dyno with no acceleration, or braking to slosh the fluid, it may be an issue, but in real world dynamics, I would be comfortable to say the fluid is absolutely moving around in the box enough to be safe on a flat tow. Unless you were extremely low on fluid, should be fine. Look at the fill plug on the transmission in relation to the center of the in/out shafts.

Aside from the thought experiment, I have friends that have flat towed their race cars for many years over many miles with 0 issues. Granted they are RWD....

[The Dark Side of Will]

Again.. If nothing is moving, why does it need lubricated? It's not in gear. It makes no difference if the engine is on or off.

The output shaft is turning in a flat tow situation.

That means that all the needle bearings where the 1st, 2nd, 3rd & 5th gears ride on the output shaft are turning, but there aren't any gears turning to get the oil moving, so there's basically no lubrication for those needles. Oh yeah, and the pilot bearing/bushing where the output shaft centers in the back of the input shaft.

Also, coasting down a hill with the engine running turns all the gears and gets oil moving.

Tie the clutch pedal down and put the trans in 5th could work.

[nando]

The transmission is typically lubricated by turning the *input* shaft. Towing with the engine off means that you are spinning parts of the trans dry. IIRC, BMW says max 50 miles.

Coasting down a hill in neutral for 200 miles would be bad, too.

Again.. If nothing is moving, why does it need lubricated? It's not in gear. It makes no difference if the engine is on or off.

[2002tiiguy]

im pretty sure the only issue is with the auto cars... and bmw says even for those just add a quart of atf to the transmission

[Kershaw]

Huh, that's really interesting. Because of that comment I did some googling, some people suggest raising the idle to 1500rpm as well. Wouldn't be that hard with a zip tie.