Flat or Dinghy Tow a Tacoma - why not?

4wd has nothing to do with it. in 2hi, the front drive shaft and front driver cv are disconnected and can spin independently of everything. And 2hi input and output shafts are spinning at the same rate (what im saying is the tcase knows no difference where rotation is coming from, so if oil pumps are in there, it wont matter).

Manual trans tho, pretty sure it has an oil circulation pump on the INPUT shaft (or the input shaft is the main sloshing mechanism).... running down the road in neutral without the motor running leads to no lubrication

 

You're mixing your metaphors.


there is no pump, there is no auto trans. there is no frt. disconnect.

 

Like i said, either an oil pump or essentially the main input shaft of the RA60 trans is a main sloshing mechanism.

Also there 100% is a front disconnect at the transfercase, to disconnect the front driveshaft (also another actuator to disconnect the front passenger cv) when in 2hi.

 

transfer case is main concern, transmission will be fine.

 

Well crap! I've been flat towing my 09 4x4 auto for a while now, I just put the tranny in nooch and leave it running! Time will tell!

 

nd4spd is correct that in 2HI the driverside front axle shaft is spinning all the time with ADD, the passenger front axle is disconnected electronically. And in 2HI the front driveshaft is disconnected in the transfer case.

I see this thread where the guy determined in 2HI the transfer case chain is not turning https://www.tacomaworld.com/threads...chain-spin-in-2wd-on-a-2nd-gen-tacoma.287787/

So, with a manual trans if you disconnected the rear drive shaft, truck in 2HI, trans in neutral, seems like the internals of both the transmission and the transfer case would not be moving at all.

Seems like it would be fine to dinghy tow with only disco'ing the rear drive shaft.

 

Everything I'm Googling says that is fine. I'm also leading to believe flat tow is fine for OP

edit: or not (laughs) conflicting for sure.

 

Here is what I heard from a Toyota line mechanic FWIW - When the manual transmission is being driven by the engine, the transmission input shaft is engaged and continually driving the transmission cluster gear or counter shaft. The cluster gear is effectively submerged in transmission oil. All of the forward gears and syncronizers are spinning on the cluster and input shaft and being lubricated by the oil being picked by the spinning counter shaft gears. When being towed in neutral, engine off, the driveshaft is turning the output shaft only, but, not the counter shaft or cluster gear, just an idler at the rear of the cluster used to engage reverse. Since the transmission input shaft and counter shaft gears and bearings are dependent on constant engagement of the input shaft for lubrication, spinning the output shaft in neutral won't supply sufficient lube to the tranny. Hence, Toyota's recommendation not to tow 4 down.

 

that's what I said. It's not a theory, its's fact. tow in neutral and you're basically spinning the tranny without any lube.

 

I'm having a hard time of with "spinning the transmission with no lube". The front of the transmission is always spinning. If you pull the engine and move the car the transmission spins. Isn't that the whole point of the throwout bearing? It matches the speed of the transmission (powered by the rear wheels) with the engine (idling at whatever RMP's your foot has it on). Also, if I was going a 100MPH down a 4 mile hill your saying that my transmission has no lube and will damage it. Not buying it.

As for the front drive shaft it is disconnected from in the transfer case in 2HI. Easy to tell if when you lift the car with the rear wheels on the ground the front spins freely (yeah, yeah open diff but you can tell). So the way I look at it the rear is going through the transfer case to the transmission and it does move the transmission all the way to the front - therefore keeps it lubed. People have been towing manual transmission cars for years soo.....

I will call REMCO today but am skeptical about there answer since they are going to try to sell me a drive shaft de-coupler. No point in telling me I don't need one. We do have a 4 wheel drive transmission shop close by that I'll also ask today. I'll report back shortly.

Meanwhile the base plat (https://www.etrailer.com/qs/189943V3) arriving today and the cable for my ready brute tow bar.

Thanks for all your input and stay tuned.

 

Ok All...

I went to a transmission place close by and they do a lot of work with 4x4's. Plenty of Gen 1 Tacoma's and Jeeps in various states of beat up ness out side the shop. He had not worked on a Gen 2 but couldn't see a reason why I couldn't flat tow my truck with the current setup.

I then went over to the local Toyota dealer (one of the best) and spent 45 minutes talking with the service manager. He could find no reason in Toyota's database why you can't flat tow. After discussing my truck and the setup he could find no reason why I couldn't successfully flat tow the truck. I told him I wouldn't hold him or the dealership responsible for any advice. He said even if the input shaft was not moving there would be plenty of gears inside moving anyway to keep everything lubed up.

So I'm out to tow and will let you guys know next week if I make the 100 mile trip to the campground I'm staying at.

 

The front of the transmission is NOT always spinning....When the engine is OFF, the input shaft does not rotate.
When you are towing 4 down, the engine is off, the transmission is in neutral. When the engine is OFF, there is NO "input" to the transmission. The only thing "spinning" is the output shaft, being driven by the driveshaft, being driven by the rear wheels on the ground. In neutral, the output shaft is disconnected from the input shaft, which drives the cluster gear, which provides the lubrication for the gears, syncronizers and bearings. IF, you were going 100mph downhill, in neutral, with the ENGINE OFF, yes you could damage the tranny due to lack of lube.
Ps - your misinformed about the purpose of the throw out bearing - google it

 

I agree that the spinning cluster gear is the principle force in flinging gear oil everywhere and that gear is stationary when the engine is off and the transmission is in neutral. However, people have been towing manual transmission vehicles in neutral since the invention of the manual transmission. So, there must be something still dipping in the gear oil and flinging it around. I suspect it's the synchronizers, which are splined to the output shaft. I firmly believe that you will be fine. But, DISCLAIMER, unless someone has done it with a 2nd gen Tacoma, with success, nobody knows what the outcome will be. However, if there is a failure, it is my opinion that the failure will be that the output shaft will weld itself to the input shaft and start turning the motor.

For further evidence to back up my theory that it will be OK, read the tow truck towing part of the manual. It says they recommend putting the rear wheels on dollies, but if dollies aren't available, put the transfer case in 2H and transmission in neutral. There is no limitation given for speed or distance. For automatics, it says don't do it. Logic would tell you that automatics will be damaged, but manuals would not.

If it were my truck, I would make sure the trans is full and hit the road. What you decide to do is your decision based on information, warnings, and possible failure or liability theories.

 

Thanks for the info. Admittedly my knowledge of transmissions is limited to clutch changes and my own theories. I stand corrected on the lube aspect. I'll be towing it on Thursday so we're going to find out what happens.

 

I don't think you will experience an immediate catastrophic failure...in fact, residual oil on the main shaft, gears and bearings will keep things lubed for ??? towing miles. But, extended towing (whatever that turns out to be, and you will know when you tow too far) will put you in the market for a replacement tranny. Good Luck

 

Last fall, I bought a Jeep as a 'fixer-upper'... I did not have a chance to road test it before buying it. After repairing it, on the first drive, it would not stay in 3rd gear... I could put the transmission into 3rd, but when I would let out the clutch, it would kick the shifter back into neutral.

I pulled the trans out and disassembled it... and discovered that the 3-4 shift fork had about 1/4 inch worn off the 3rd gear pressure face.

After doing some research, I read that this happens in vehicles that are flat towed behind RVs for extended periods...

I haven't been able to wrap my head around how towing would cause that type of wear... unless something was putting constant pressure on the shifter, pushing it towards the 3rd gear 'gate' (if that is vaguely clear)... IDK...

Just repeating what I read, and also had a transmission repairman tell me the same thing.

I replaced the shift fork and now all is good...

-Bear

 

Interesting. I'll key an eye out for that behavior.

 

All set up for flat towing. 2 receivers and 1 brake cable the pulls when the surge arm on the ready brute tow bar pulls it.

 

Well I flat towed the truck 120 miles at 60mph and nothing happened. No fire, no transmission locking up, no parts falling off, no lawyers popping up.

I have since driven the truck around the DC beltway and that gives the clutch quite a workout. Again, nothing has changed in the way the truck drives. I even put it in 4 wheel drive and all is good.

Preparation for towing was as follows.
1) Warm up the engine to normal operating temp.
2) Key in accessory mode. So the steering wheel does not lock.
3) Transmission in neutral.
4) Parking brake off.
5) Tow

Now maybe there may be long term issues but so far so good.

 

You mean transmission in neutral, right?