NO Damage to auto transmission by EOC

[ScottC33]

I have an '07 Toyota Tundra and am getting 21-22 MPG (combined -- 85% highway driving) by using basic hypermiling techniques. The sticker said 16/20.

I'm looking to do some EOC, but WAS concerned about damage to the automatic transmission. I talked to the service department at the Toyota dealership, and the guy said I will do NO damage to the transmission by coasting with the engine off for a short period of time (ex. down a hill) or by shifting in and out of neutral.

As far as EOC goes, he agreed that, since the engine is off, the transmission isn't doing anything. There's no damage to be done.

Does anyone have any contrary information? People talk a lot, but often know very little about what they are talking about. It's really amazing. If anyone KNOWS that this information I got is wrong, by all means, speak up. I really want to try the EOC, but don't want to fry a $4,000 transmission in the process.

Thanks in advance for any input you may have.

Scott

[Daox]

Welcome to the site ScottC33.

The same rule goes for all vehicles. Check your owners manual to see if your vehicle can be flat towed or not.

Since you are moving, and your wheels are rotating, and the wheels are directly connected to parts of the transmission which are then also rotating, parts of the transmission are moving and it is possible they are not going to get lubricated properly with the engine off.

[millenniumtree]

Originally Posted by Daox

Check your owners manual to see if your vehicle can be flat towed or not.

Ding ding ding ding ding!!!
That's the best answer I've ever heard regarding this issue. Seems so obvious now. :P

[SuperTrooper]

The most comprehensive list I've seen for vehicles that CAN be flat towed is Motorhome Magazine's towing guide:

Dinghy Towing Basics

The Tundra is NOT on the list for 2007 vehicles.

[trikkonceptz]

I know only time and repair bills wil tell, but EOC vs Flat tow are to completely different subjects. Other than the extreme EOC'ers here I couldn't imagine anyone EOCing for more than a mile at a time and if they do they probably have manual tranny's.

I for one, EOC an Automatic also, the longest stretch I have EOC'd is 3/4 of a mile, I have no hills here. Therefore I have convinced myself that with synthetic oil in the tranny pan, there is enough sloshing around the tranny to keep it safe for short distances.

But again, that is an untested opinion, but if I'm wrong then I will simply switch to a manual tranny and be done with it ..

[Tourigjm]

Originally Posted by trikkonceptz

But again, that is an untested opinion, but if I'm wrong then I will simply switch to a manual tranny and be done with it ..

Same here, I don't EOC on the highway though, glides are too short.

I only EOC in town... Gotten out and pushed too

[Arminius]

I've never seen a manual say that coasting in neutral with the engine on will void a warranty. If people are concerned about EOC, they can still use neutral. It won't be quite as efficient, but it will be close. I will continue to EOC, however.

I EOC for more than a mile (1.2 miles) at least once a day.

[ATaylorRacing]

I know for a fact that Chyrsler trannies when coasting in neutral with the engine shut off can be ruined fairly quickly if coastibg at over 25 mph.....the engine must be runing for the pump to be circulating the fluid....if you see one being flat towed they have hooked up an electrical pump to not have any troubles. The longest EOC I did was about8 miles at one time....leaving Rock City.

[trikkonceptz]

Originally Posted by Arminius

I've never seen a manual say that coasting in neutral with the engine on will void a warranty.

And you won't because;
-It's impossible to prove a failure as a result of Coasting
-Until someone gets hurt doing it, sues and wins, you won't see it printed.

The best example of this is the customer who bought an RV, set the cruise control and left the wheel. Obviously crashed, then sued the RV company and won because it didn't say she had to stay behind the wheel while in cruise control. It says it now ... LOL

[atomicradish]

I used to EOC in an old Metro before it finally bit the dust. The auto tranny was crapped out and you had to shift using the gear shifter. Simply putting it in D would not work. Sometimes it would start off in 2nd gear and do 0 - 60 in about 30 seconds. Anyway, I was hoping I could kill it off for good using EOC... nope. I think EOC is fine in automatic as long as you're not coasting for extreme distances. I would be weary of distances over a mile, but distances less than that not so much. From my understanding, the transmission is not getting vital oil and lubricants during when being flat towed. Unless you're coasting for extremely long distances I doubt you would have enough time to burn up the transmission.

Of course my opinion is untested as well.... just don't come knocking on my door if your tranny bites the dust.