Changing transmission fluid

[Homer]

I drained the oil pan on my auto. transmission today and 82 ounces came out, it had a hint of red but mostly brown. Odometer says 28,600 miles.  The Haynes Toyota Pickups '79 thru '95  Repair Manual , Chapter 1  page 1-2 says in the routine maintenance that capacities  for 4cylinder is 2.5 qts.  After it drained for about 3 hours I put the plug back in and measured  76 ounces of Dexron III out of a gallon jug.  Somewhere I read that it took about 16 quarts to flush all the old out and replace it with new.  I suppose that that includes the torque converter and extra oil cooler. My son-n-law works for a Nissan dealer and does their maintenance for them. He said to just drain the pan and put the same amount of new fluid  back in. Drive it about 1K miles and do it again.  He said that replacing a little at a time is the best way to change it out. He said that some shops flush the  transmission system and it brings on problems???  Have I done wrong ? OR, is this the correct way to change it. I doubt that the fluid had ever been changed since new by the color of it ???  I meant to do it sooner but haven't taken time. It only had 26 K on it when we purchased it in 2009.

Thanks,
Tom

 

 

 

[linda s]

Yup That is the way I would and did do mine.

Linda S

[jjrbus]

Not knowing the history of my fluid I wanted to get it all out and replace with fresh fluid.   I went to  You Tube and watched several videos on automatic transmission fluid flush.  I did it the way it was shown and have had no issues. Sounds scary but no big deal actually, just letting the transmission pump the old fluid out as you install new.

[Back East Don]

I am going to suggest a somewhat different direction.  I am typically a do it yourself-er but I draw the line at certain points.  The transmission with the 4 cyl is pretty solid but has a bushing in the tailpiece that is prone to wear.  Mine had just over 50k miles when I purchased it.  Last year at around 60k I noticed I was dripping trans fluid out the end seal.  So I searched through and found a couple posts including the transmission sticky in this section.  A bit of a slog to read through but the long and short of it is that the bushing wear will affect more than just the output shaft seals and is more than just a minor issue in the long run.  If the plan is to keep this running in good condition over the long haul, it has been suggested to add this bushing to the maint schedule with the fluid change.  Perhaps you are comfortable with this type of work, I was not.  So I found a good indie shop that does a lot of hot rods and older vehicles.  He had some familiarity with this transmission.  I explained that I researched the transmission and that other than the leak, mine was running perfectly.  I asked him to replace the bushing and seals along with dropping the pan and replacing the filter screen and fluid.  I also specifically asked for a Duraprene gasket for the pan.  Those here who have done transmission work have suggested it is a better solution to other gasket materials. 

Total cost was around $400 to have it done.  Well worth it to me to have someone else do it.  Your opinion on that may differ.

[linda s]

I see no reason to change a tail house extension bushing that isn't leaking. Mine has never leaked on my 86 so I don't really think it's a widespread problem. I do change my fluid regularly though. Probably every 2 years.

Linda S

[zero]

That rear tailshaft bushing is prone to wear on vehicles that have driveshafts that use that bushing as the slip-joint for the driveshaft.  Toyota does - but when the rear suspension is good, there is very little fore-and-aft movement to cause that wear. GM is known for that problem in light-duty trucks with a one-piece driveshaft (no slip-splines). So are some Ford trucks.  I've never heard of Toyota trucks having any abnormal wear problems with that area.  I know mine is fine and my trans has 150K miles on it.  On my Chevy K5 Blazers and Suburbans - I often had to change rear seals every 40K miles and they did suffer from tailshaft bushing wear.

On a side-note - the A43D has two seals in the rear and I have come across several that when a seal change was done, one of those seals was discarded. I suspect because it is not available aftermarket. It is reusable if care is used when removing it.  It is a heavy felt dust seal in a steel cage.  It is there to keep grit from entering the other seal that is a spring-loaded lip-seal.

[Back East Don]

53 minutes ago, linda s said:

I see no reason to change a tail house extension bushing that isn't leaking. Mine has never leaked on my 86 so I don't really think it's a widespread problem. I do change my fluid regularly though. Probably every 2 years.

Linda S

I barely have any anecdotal evidence so I'm not making a definitive stance.  Only will suggest that few look that deep at their undercarriage till there is a problem.  Checking both for play and leaks is a starting point.  The transmission shop said I was at about the limit of wear and had it gotten much worse, I'd be looking at a more extensive repair.  Seems to me that by the time it starts leaking, you've already got a decent amount of damage.  The point at which it started to show leakage on the driveway happened rather suddenly.  Glad I dealt with it quickly. How much more did it cost me over just a transmission flush?  Much cheaper than a more extensive repair or transmission rebuild.

4 minutes ago, jdemaris said:

but when the rear suspension is good, there is very little fore-and-aft movement to cause that wear.

I've got the lighter 19 footer without air bags.  I've a third the miles you have.  Not sure what the causes are for the differences in service life.  The shocks might have been worn when I got it but only the steering stabilizer was to the point of being ineffective. Meaning handling wasn't bad nor was the ride at least for the shocks.  While I've owned it for over 6 years, this is only the second year where it got regular use.  The first year I put about 6k miles then it sat barely used for 3 years. Finally last year I while getting it ready for use again I found the leaking tailpiece. The wear itself would have likely happened long before the miles I put on it.  The miles I put on it were only over one summer and all smooth highway miles.

So I still think it is good to keep an eye out because dealing with it early will save you a ton of money vs a much more expensive repair.

 

[zero]

Generally speaking - tailshaft bushing wear is caused by two things.  One is excess fore-and-aft driveshaft travel.  Two - is towing a motorhome without removing the driveshaft.

[linda s]

Yes absolutely if it's leaking the source needs to be addressed. But if it ain't broke don't fix it. I have seen quite a few members go overboard prematurely repairing stuff that might go bad. Many times they end up causing more problems.

Linda S

[DanAatTheCape]

I would not do a a"power flush" to an older tranny.  You can break lose minute bits of sludge which can cause real problems...

 

I would either do the drain the pan (about 2 qts) and keep repeating -or- remove the line going to the tranny cooler (bottom of radiator) and with a helper add in new fluid as the old is pumped out (engine running).  I went for the former as that was most idiot proof.

My 93 winnie warrior 6 cyl has a drain plug on the tranny pan - about every 10k miles I drain off the 2 quarts and refill.

 

 

[bicoastal eric]

I think the drain and fill and repeat is the generally prefer method. I use Walmart dex6.

My 87 21' with 180k miles had a worn and leaking tail shaft bearing and seal. 

I drove it like that from Maine to Colorado, went through probably 10 gallons of atf. Found a good shop in Denver to fix it for about $500. No problems after that. 

But if it ain't broke....

Then just check your fluid periodically.