Honda Odyssey Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #1 ·
This is just a curiosity question...

Let's say you have overfilled your tranny. My understanding is that the ATF fluid will get frothy and cause shifting issues and maybe even long term tranny problems.

My question is this: When will the shifting issues become evident? Right away, like as soon as the fluid reaches normal operating temperature the first time? Or maybe you'll be fine around town and some short distance highway driving, but suddenly 2 hours into a long trip things will start to go bad.

IOW, If you haven't experienced anything strange after a few days of local driving, is it safe to relax on that 600 mile drive?

And what if it does start to slip 2 hours into the long trip? Can you safely and carefully continue on to your destination and take care of it when you get there?

Thanks for any thoughts on this.
 

·
Registered
2006 ExL, 2012 Touring
Joined
·
8 Posts
I'm actually not sure on this platform but I could be missing something. Why not just check dipstick? Get van to operating temp, pull dipstick out. Clean it off and send us a pic.
 

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #3 ·
I'm actually not sure on this platform but I could be missing something. Why not just check dipstick? Get van to operating temp, pull dipstick out. Clean it off and send us a pic.
Yes, of course that's the solution for anyone that maintains their vehicles properly. Heck, some drivers never check their own fluids. In fact, I know for a fact that there are driver's that think that Honda's "oil life indicator" means that we never have to check our oil level.

This question is just about the symptoms of an overfill.

I talking about a possible situation where someone asks a shop to do a drain and fill, they take out the "standard" 3.4 quarts and pour a full 4 quarts in. When will the issues present themselves?
 

·
Registered
2006 ExL, 2012 Touring
Joined
·
8 Posts
Ok gotcha. I'm not too sure on that one, but I've read that slightly more fluid is ok but not sure how much it will take to see issues and how long it would take. Sorry I'm not much help but I'll keep an eye on this to learn more. Best of luck 👍
 

·
Registered
Joined
·
166 Posts
Check the transmission fluid dipstick. If overfilled, get one of those cheap fluid transfer pumps and suction some out through the dipstick hole.

If your transmission is slipping, reduce your speed and drive in D4 to reduce stress on the transmission and fluid.

1/2 qt overfilled should not be an issue. Same with engine oil. I think manufacturers put in a little buffer so that a small overfill does not result in a catastrophic failure.
 

·
Registered
2016 Touring Elite
Joined
·
2,134 Posts
1/2 qt overfilled should not be an issue. Same with engine oil. I think manufacturers put in a little buffer so that a small overfill does not result in a catastrophic failure.
I don't think anyone has a good answer since every transmission (and engine, for that matter) has a different 'overfill' capacity and effects if overfilled. If it hasn't misbehaved after a 15+ minute drive, you are likely fairly safe on longer trips.

The auto trans that was in my '89 Camry would have shifting issues if it was more than a a couple ounces overfilled. That showed itself by sluggish downshifts after freeway driving. The transmission in my 4Runner can be overfilled by a quart and will show no effects. Different transmissions, different effects. Some engines MUST be overfilled by >0.5 quarts if you intend to drive the car on the racetrack (or it starves the engine of oil on corners). Other engines might froth the oil and blow oil into the cylinders and eat bearings with that much extra oil...

-Charlie
 

·
Registered
2006 ExL, 2012 Touring
Joined
·
8 Posts
I don't think anyone has a good answer since every transmission (and engine, for that matter) has a different 'overfill' capacity and effects if overfilled. If it hasn't misbehaved after a 15+ minute drive, you are likely fairly safe on longer trips.

The auto trans that was in my '89 Camry would have shifting issues if it was more than a a couple ounces overfilled. That showed itself by sluggish downshifts after freeway driving. The transmission in my 4Runner can be overfilled by a quart and will show no effects. Different transmissions, different effects. Some engines MUST be overfilled by >0.5 quarts if you intend to drive the car on the racetrack (or it starves the engine of oil on corners). Other engines might froth the oil and blow oil into the cylinders and eat bearings with that much extra oil...

-Charlie
Well put. C8 takes 2 quarts of extra trans fluid 😬
 

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #9 ·
I don't think anyone has a good answer since every transmission (and engine, for that matter) has a different 'overfill' capacity and effects if overfilled. If it hasn't misbehaved after a 15+ minute drive, you are likely fairly safe on longer trips.

The auto trans that was in my '89 Camry would have shifting issues if it was more than a a couple ounces overfilled. That showed itself by sluggish downshifts after freeway driving. The transmission in my 4Runner can be overfilled by a quart and will show no effects. Different transmissions, different effects. Some engines MUST be overfilled by >0.5 quarts if you intend to drive the car on the racetrack (or it starves the engine of oil on corners). Other engines might froth the oil and blow oil into the cylinders and eat bearings with that much extra oil...

-Charlie
Thanks for that answer. I guess I should have been more specific, but since I posted in a 2011-2017 Honda Odyssey forum, I assumed (but not consciously) that the collective group would have known that I was asking about our own beloved Ody's. ;) I can certainly see your point though. My error.

In any case, you've answered my question: In general, one would expect to see problems during the first drive and (more or less) as soon as the fluid has warmed up.

Thanks again!
 

·
Registered
Joined
·
912 Posts
Thanks for that answer. I guess I should have been more specific, but since I posted in a 2011-2017 Honda Odyssey forum, I assumed (but not consciously) that the collective group would have known that I was asking about our own beloved Ody's. ;) I can certainly see your point though. My error.

In any case, you've answered my question: In general, one would expect to see problems during the first drive and (more or less) as soon as the fluid has warmed up.

Thanks again!
My 2001, was rebuilt. And overfilled by 3.5 quarts. Drove it for hundreds of miles. I noticed the "overfill", when I checked the level. Never thought to check the tranny level, since I just had the tranny rebuilt. Anyways, 50,000+ miles later had tranny rebuild again. (however, 2001, known for poor/junk trannys. So the failure not due to overfill IMHO).
Currently on 4th tranny. Going strong. Added magnefine filter, and tranny drain/fill 8000 miles or sooner.
 

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #11 ·
My 2001, was rebuilt. And overfilled by 3.5 quarts. Drove it for hundreds of miles. I noticed the "overfill", when I checked the level. Never thought to check the tranny level, since I just had the tranny rebuilt. Anyways, 50,000+ miles later had tranny rebuild again. (however, 2001, known for poor/junk trannys. So the failure not due to overfill IMHO).
Currently on 4th tranny. Going strong. Added manifine filter, and tranny drain/flush 8000 miles or sooner.
You flush your transmission every 8000 miles?
 

·
Registered
2006 Honda Odyssey (EX)
Joined
·
3,048 Posts
You flush your transmission every 8000 miles?
They said drain/flush, so I'm assuming they mean a 3x drain and fill, commonly referred to as a "flush".
 

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #14 ·
They said drain/flush, so I'm assuming they mean a 3x drain and fill, commonly referred to as a "flush".
I don’t think I’ve ever heard of a drain and fill referred to as a “flush”, even if it’s a 3X.

AFAIK what’s more commonly said is “Don’t do a flush, do a 3X drain and fill.”

As I’m sure you know, a flush is a very specific procedure, using specialized equipment.
 

·
Registered
2006 Honda Odyssey (EX)
Joined
·
3,048 Posts
I don’t think I’ve ever heard of a drain and fill referred to as a “flush”, even if it’s a 3X.

AFAIK what’s more commonly said is “Don’t do a flush, do a 3X drain and fill.”

As I’m sure you know, a flush is a very specific procedure, using specialized equipment.
Yeah, but Honda has historically used the term flush and 3x drain and fill interchangeably IIRC.
 

·
Registered
Joined
·
2,088 Posts
Discussion Starter · #16 ·
Yeah, but Honda has historically used the term flush and 3x drain and fill interchangeably IIRC.
Right you are...found it here.


"NOTE: American Honda defines flushing the transmission as draining and filling the transmission with a drive cycle three times to help make sure the deteriorated fluid is removed. There are other aftermarket flush systems available, but American Honda does not recommend using them."
 
  • Like
Reactions: WiiMaster
1 - 16 of 16 Posts
Top