Help! Honda hitch question....

[tlhdoc]

I change the transfluid (3 qts) every other oil change during the towing season as cheap insurance against problems

Chris how do you change just 3 quarts or transmission fluid?  In our Explorer you have to drop the pan to change the fluid, so it isn't possible to change just 3 quarts.

[DiW]

Ahha, that's the question!   Although the Honda tranny holds 6.2 qts of transfluid and there is a handy-dandy drain plug, when you drain the trans, only three qts actually drain from the pan.  The remainder of the fluid is captive in the torque convertor. In order to truely change all the fluid, you have to change 3 qts three times which results in a change of ~90% of all the fluid.  All the maintenance threads on Odyclub.com talk about this.  When I do a full change I do the three 3qt changes a few hundred miles apart. After that I change the 3 quarts every other oil change to keep the transfluid fresh.  '99 to '05 Odysseys have reliability issues with transmissions so I err on the side of caution and change it frequently - it's cheap insurance.

[esclark]

Thanks for all your input!  We went with the class III hitch.  We put the Yuma on the Odyssey and it didn't move the van which is good.  I think having the electric brakes is also a huge help.  

Anyhow, looking forward to seeing you all in the forums.

E&S Clark
2005 Fleetwood Yuma
2004 Honda Odyssey

[tlhdoc]

So when and where will your first trip be?

[esclark]

We really like it up in Peninsula State Park (Fish Creek, Wisconsin).  It's in Door County which is just a really neat area with lots to do.  It reminds us of New England but it's close to home.  Before we head up there, we will take the pop-up out somewhere close to home.  It will all be weather permitting because it is northern Illinois and it's only March.

How about you?

[wynot]

Chris how do you change just 3 quarts or transmission fluid? In our Explorer you have to drop the pan to change the fluid, so it isn't possible to change just 3 quarts.

Tracy,
 
If you get 3 qts out of a normal automatic dropping the pan, you've gotten a fair amount out.  Most fluid stays up in the torque converter, and only my one vehicle has a way to drain it as well.
 
Most traditional places have only ever dropped the pan and cleaned the screen for tranny fluid changes.  Now, most of them are hooking up to a pumping arrangement (and charging you for a LOT of fluid, most of which is not staying in the transmission - because it is used for flushing the system).

[SpeakEasy]

OK, so here's a question for my own learning.

With an engine oil change, if you don't get out all the old oil, it reduces the effectiveness of the change. That is, if there's "pollution" left in some oil left in the oilpan, it continues to circulate in your new oil, causing wear. For this reason I always change the oil filter at the same time I change the oil. Some folks say to change the filter every other time, but it doesn't make sense to me to leave a pint or so of old oil circulating.

Is this different with transmission oil? If you are only removing 3 quarts out of the 9 or whatever, aren't you wasting your time? Wouldn't there be bits of metal and such continuing to circulate in the "changed" transmission oil?

[wavery]

Trans oil is a lot different than motor oil. It does not get the contaminates that motor oil does. Most of the contaminates in motor oil are derived from combustion not wear. It is a very good idea to change the filter each time.

Trans oil is pretty well in a sealed system and doesn't suffer from contaminates and acid build up (as much) . The big thing that effects trans oil is heat. There is a small amount of wear particles in the oil but not enough to be concerned about.

Changing as much of the trans oil as possible is good. The detergents break down over time and the other additives burn up with heat. Adding fresh oil, adds new additives and detergent, keeping the trans clean. If you see your trans oil getting brown, that is the additives that have burnt. If you see that, get all of the trans oil out. The burnt additives become gooey over time and will cause the tiny little valves in the valve body to malfunction. It also cause excessive wear and increases the temperature instead of acting as a coolant. If your trans oil is black, it's time to get rid of that vehicle. Chances are, there is significant damage to the trans.

I highly recommend switching to synthetic oil. The cooling properties are far superior and therefore the additives don't burn and everything, including the fluid, lasts much longer.

I would avoid having your trans flushed unless you have less than 25K miles on your car. Even if you use the flush, make sure that they drop the pan, clean it and change the filter afterwords. They will tell you that it isn't necessary but that is simply NOT true. That filer still has trapped contaminates and it falls apart over time. The flush actually increases the degradation of the filter.

If you have ever changed a trans filter or seen your trans being serviced, you will have seen that the technician takes the pan over to a solvent tank and cleans it out. Most of the contaminates in your trans end up on the bottom of the oil pan, not in the filter. That is why most manufacturers don't put a drain plug in the pan. It is essential that the pan be removed and cleaned.

During the trans flush, all of the sludge that has settled to the bottom of the pan is disturbed and circulated through the trans and gets trapped in the filter.  If the pan is not propped, cleaned and filter replaced, a flush can do more harm than good.

[wynot]

OK, so here's a question for my own learning.
 
With an engine oil change, if you don't get out all the old oil, it reduces the effectiveness of the change. That is, if there's "pollution" left in some oil left in the oilpan, it continues to circulate in your new oil, causing wear. For this reason I always change the oil filter at the same time I change the oil. Some folks say to change the filter every other time, but it doesn't make sense to me to leave a pint or so of old oil circulating.
 
Is this different with transmission oil? If you are only removing 3 quarts out of the 9 or whatever, aren't you wasting your time? Wouldn't there be bits of metal and such continuing to circulate in the "changed" transmission oil?

As someone who changes his own motor oil because he doesn't trust anyone else to do it (lest they leave a quart of dirty oil in there), you have hit the nail on the head.  I think the ATF should be able to have a complete change too, but the very nature of the A/T prevents it being done easily, unless you have a way to pump the fluid through it.
 
Automatics are funny creatures.  If you don't really abuse the tranny (like towing...), you can ignore changing the fluid and probably sell the car before the tranny fails, often in excess of 150,000 miles.  If you are religious about changing the fluid, the tranny will probably last the reasonable life of the car - and this is with the "part change", because that was the way we did it for most of the years that the automatic transmission has been in routine production.
 
Heat and slippage are what normally cause the ATF (and subsequently the A/T) to fail.  I think the number commonly used is that dropping the ATF temperature 20 degrees DOUBLES the life of the fluid.  If the transmission slips, it overheats; if it is low or high on fluid, it overheats.  And the "smoother" the A/T shifts, the hotter it will run (smooth = slippage).  One of the reasons that people doing performance mods to their cars use a trick transmission fluid with friction modifiers, to firm up and speed up the shifts.
 
If I remember correctly, ATF was one of the first "synthetic" fluids used in vehicles, so if that is correct, it probably has a certain amount of durability built in.
 
I think the short answer is that:
 
- It's better to change at least some of the fluid, and hope that you get out the older fluid next change...
 
I also believe this is why the quickie lube places recommend 3,000 mile/3 mos oil changes for engine oil - because they know they can't drain the oil oil completely in 3 minutes, and if they get you back in, you will have a majority of clean fresh oil every 3K miles.

[wavery]

Your analogy of "smooth=slippage" is true but it is not necessarily a bad thing. You want the trans to shift smoothly because it reduces the amount of impact on transmission gears during shifting. This is a good thing not a negative. Fast rough shifting causes premature failure due to warn "Hard parts" like gears and shafts.

Logic might tell you that faster shifting will eliminate wear on the fiber clutches because there is less friction. However, that is the very function of ATF. The ATF acts as a buffer between the clutches and most of the shifting is a hydraulic friction as apposed to a fiber material contact friction. When you change the properties of the ATF to cause harder shifting, you are actually causing more fiber friction, not less.

The hard shifting may be cool for getting 2nd gear rubber while shifting but not so cool if you want a transmission to last and definitely NOT cool when towing.

[wynot]

Your analogy of "smooth=slippage" is true but it is not necessarily a bad thing. You want the trans to shift smoothly because it reduces the amount of impact on transmission gears during shifting. This is a good thing not a negative. Fast rough shifting causes premature failure due to warn "Hard parts" like gears and shafts.
 
Logic might tell you that faster shifting will eliminate wear on the fiber clutches because there is less friction. However, that is the very function of ATF. The ATF acts as a buffer between the clutches and most of the shifting is a hydraulic friction as apposed to a fiber material contact friction. When you change the properties of the ATF to cause harder shifting, you are actually causing more fiber friction, not less.
 
The hard shifting may be cool for getting 2nd gear rubber while shifting but not so cool if you want a transmission to last and definitely NOT cool when towing.

Personally, I DON'T want to feel the transmission shift, which is why I let up slightly when it's ready to shift.  When I had my tranny serviced a few weeks ago, they put some trans conditioner in my normal driver which has firmed up the shifts slightly, and I wish they would have left well enough alone.

[wavery]

I never recommend additives to ATF. They often have chemicals to "Rejuvenate" seals. The fact is, they cause the seals in the transmission to swell. Although that may cause some seals stop leaking (temporarily), they also change the pressure regulation inside the trans (by swelling seals that should not be swolen) and often cause more problems then they cure. Hard shifting is a symptom of changing pressure regulation to the clutch-pack. There is NEVER a good reason to put additives in your trans IMHO. If it leaks, you have a bad seal(s), replace it. It just doesn't get any more plain than that.

The fact is, all of these garages, dealerships, etc make $ by selling chemicals. In most cases, there is some sort of incentive scheme that goes all the way from the purchasing agent, management, service salesman and even the technician. I have always hated these schemes. They are dishonest, deceptive and often time do more harm then good because they "Dump" the stuff into vehicles that don't need it. That goes for engine oil additives, fuel additives, trans additives and P/S additives. It is not uncommon for some places to dump all of the above into every vehicle that goes through the shop. If the customer complains, they simply remove it from the bill. 90% of customers not only don't complain, they have no idea how to read the charges on their bill.

[tlhdoc]

We really like it up in Peninsula State Park (Fish Creek, Wisconsin). It's in Door County which is just a really neat area with lots to do. It reminds us of New England but it's close to home. Before we head up there, we will take the pop-up out somewhere close to home. It will all be weather permitting because it is northern Illinois and it's only March.
 
How about you?

We were out for a long weekend in February and our next trip will be 5 or 6 nights at Assateague Island National Seashore for Easter.

[aw738]

With Hondas and Mazdas the trans filter cannot be changed without removing and dismantaling the transmission.  :eyecrazy: The people who design these things should be made to work on them.

[wynot]

With Hondas and Mazdas the trans filter cannot be changed without removing and dismantaling the transmission. :eyecrazy: The people who design these things should be made to work on them.

That's true of most all of them. I'm sure you don't mean removing the transmission, but instead removing the pan, then removing the screen from the valve body...DON'T you? I have a rare thing in my Audi's tranny, it's called a drain plug... Of course, it doesn't come with a dipstick - heaven forbid you don't have a specialty scan tool to tell whether you have enough fluid at 75 deg C.
 
Speaking of working on them, the engineers designing the vehicle and those designing the engine should also get together.  I've had several vehicles where the oil filter was in a relatively inaccessable place - one from GM (remove the fender inner liner), and two from Ford (where the oil filter is located over a wide subframe mount, and not accessible easily from either side.)