Changing to synthetics

[LC4me]

A newbie here. I am in the process of getting my 92 up to par to be my daily driver/commuter, after essentially being reserved as a "toy" (no off-road though). Thanks to the forum, I will be baselining and will start with replacing some of the fluids this weekend.

A few questions...

1. My local Toyota dealership replaced the diff/transfer case gear oil 2000K miles ago (4 years). Due to possible breakdown due to time, should the gear oil be replaced? Also, I want to change over to synthetic...any special "procedure" or just drain the dino and refill with synthetic?

2. Dealer flushed the transmission 50K ago (10 years ago). No other PM has been done on the transmission . I plan on doing several simple drain and fills to gradually replace the old fluid with new instead of a flush (thanks Cdan for the advice). I have Advanced Auto ATF fluid for this first drain/fill, but would like to change to synthetic eventually. Is it ok to mix dino and synthetic while doing simple drain and fills?

I have been using synthetic engine oil for the past 10 years so I don't need to covert to synthetic there.

Thanks in advance!

 

[akarilo]

A few questions...

1. My local Toyota dealership replaced the diff/transfer case gear oil 2000K miles ago (4 years). Due to possible breakdown due to time, should the gear oil be replaced? Also, I want to change over to synthetic...any special "procedure" or just drain the dino and refill with synthetic?

Thanks in advance!

Oil doesn't go bad, it just becomes contaminated. One look at the fluid should tell you everything you need to know.

 

[AShoe]

Just drain the dino and refill with synthetic. I'm doing basically the same thing to my trans so i hope it is fine.

 

[lacruiser]

Re Changing the ATF:

You won't get 100% of the fluid out, but there is a much more efficient and less wasteful method than just draining, adding, and repeating.

I identified which cooler line (from the radiator) returns the fluid to the transmission, disconnected it (at the radiator), and then ran a piece of hose from the (now exposed) hose nipple (on the radiator) into a 5-gallon bucket.

i drained the transmission pan. You can remove the plug, or pull the pan and clean and replace (more thorough).

Refill the transmission pan, then start the engine, and start pouring in fluid (through the dipstick tube) while the engine is running.

The sump in the pan will suck up new fluid, pushing out the old fluid inside the transmission, through the torque converter, then out the transmission to the radiator cooler, and into the bucket.
(the disconnected hose will simply suck air during this procedure). This is the most complete exchange of fluid you can achieve, without a drain plug on the torque converter, which none of these TC's have.

You will want to have someone inside the car, shifting through all the gears while the fresh fluid is being pumped through. Stay in each gear for about 5 seconds.

You will find that after about 15 quarts of fluid, the stuff coming out will be clean fluid. You'll also find that it's difficult to keep up with the amount of fluid being pumped out. Just pour it in as fast as you can.

This procedure will replace most of the fluid inside the torque converter, and pretty much all the fluid inside the transmission. It's a very effective method and you can DIY.

 

[Cruiserdrew]

Re Changing the ATF:

You won't get 100% of the fluid out, but there is a much more efficient and less wasteful method than just draining, adding, and repeating.

I identified which cooler line (from the radiator) returns the fluid to the transmission, disconnected it (at the radiator), and then ran a piece of hose from the (now exposed) hose nipple (on the radiator) into a 5-gallon bucket.

i drained the transmission pan. You can remove the plug, or pull the pan and clean and replace (more thorough).

Refill the transmission pan, then start the engine, and start pouring in fluid (through the dipstick tube) while the engine is running.

The sump in the pan will suck up new fluid, pushing out the old fluid inside the transmission, through the torque converter, then out the transmission to the radiator cooler, and into the bucket.
(the disconnected hose will simply suck air during this procedure). This is the most complete exchange of fluid you can achieve, without a drain plug on the torque converter, which none of these TC's have.

You will find that after about 15 quarts of fluid, the stuff coming out will be clean fluid.

This procedure will replace most of the fluid inside the torque converter, and pretty much all the fluid inside the transmission. It's a very effective method and you can DIY.

This is the Rodney flush and highly recommended. In an older truck, I'd probably use a good quality name brand conventional fluid. My Rodney flush took almost 20 quarts, which adds up fast for synthetics!

 

[LC4me]

Oil doesn't go bad, it just becomes contaminated. One look at the fluid should tell you everything you need to know.

Thanks akarilo...that makes sense. I will check the condition fo the diff/trans case gear oil. If clean but just needs topping off, ok to add synthetic to the dino already in there?

Just drain the dino and refill with synthetic. I'm doing basically the same thing to my trans so i hope it is fine.

Thanks AShoe...I was hoping it would be as simple as that.

This is the Rodney flush and highly recommended. In an older truck, I'd probably use a good quality name brand conventional fluid. My Rodney flush took almost 20 quarts, which adds up fast for synthetics!

Thanks lacruiser and Cruiserdrew for responding. I read up on the Rodney flush, but Cdan advised against doing a total fluid exchange when a tranny has been neglected....all that new fluid at one time could loosen deposits causing problems. Plus, doing drain/fills is a little easier on the wallet especially since I would like to switch to synthetic. Ok to just pour in 5 qts or so of synthetic during a drain/fill to mix with the existing non-synthetic tranny fluid?

Once I get the tranny fluid mostly replaced (I know, it will take a long time) I plan to do the Rodney flush to keep it properly maintained. It sure beats paying $150 my local dealer wants for a transmission flush.

 

[CELICA XX]

Is it ok to mix dino and synthetic while doing simple drain and fills?

I don't think anyone answered the original question.

I was curious about the same thing...

Is Mobil 1 Synthetic ATF safe to use ?

 

[lacruiser]

I don't think anyone answered the original question.

I was curious about the same thing...

Is Mobil 1 Synthetic ATF safe to use ?

30 seconds on Google, and an answer:

Mobil 1 Synthetic ATF


short answer: Yes

 

[CELICA XX]

30 seconds on Google, and an answer:

Mobil 1 Synthetic ATF


short answer: Yes

uhh, the Mobil site doesn't answer the question either.

I have been to that site a thousand times.

In fact, it says to use Mobil DEXRON-VI ATF wherever DEXRON is specified... NOT Synthetic ATF.



According to Romer and the 80 series FAQ, it says to use ATF DEXRON®II

 

[lacruiser]

uhh, the Mobil site doesn't answer the question either.

I have been to that site a thousand times.

In fact, it says to use Mobil DEXRON-VI ATF wherever DEXRON is specified... NOT Synthetic ATF.



According to Romer and the 80 series FAQ, it says to use ATF DEXRON®II

uhh, right on the page I linked, on the left side, under the heading "Features" is the following entry:

"Compatible with mineral ATF fluids and all common seal materials"

it's the sixth item down.

 

[Michael Hanson]

I like pulling the pan and cleaning the metal filter.Personally never thought the Rodney flush was enough.I have never had a transmission fail ,some have gone well over 300,000 miles .All have been used in construction and pulling trailers. 2 cents MIke

 

[lacruiser]

I like pulling the pan and cleaning the metal filter.Personally never thought the Rodney flush was enough.I have never had a transmission fail ,some have gone well over 300,000 miles .All have been used in construction and pulling trailers. 2 cents MIke

I agree. I think if you're going to change to synthetics, it's smart to pull the pan and clean everything up. There's usually a bit of sludge sitting on the bottom, and usually some filings clustered around the magnet.

The rodney flush is the most efficient way to change as much of the fluid as possible, without removing and draining the torque converter.

In the old days, torque converters had a drain plug, but manufacturers stopped adding them years ago. I guess it must have saved them about 10 cents on every car?

That was the best deal. You opened the inspection port, rotated the converter till the plug was at the bottom, removed the plug, and the sucker would completely drain. Along with pan removal, it was about a 99% removal of fluid. (there was always some small amount left inside the valve body circuits, clutches, and servos, etc etc.)

So, absent a drain plug, there is no better way (other than physical removal) to drain/exchange the old fluid than using the "Rodney Flush".

 

[96r50]

Is Mobil 1 Synthetic ATF safe to use ?

I, and I'm sure many others on here, have used Mobil 1 synthetic ATF as part of a drain and fill routine or as a complete "rodney flush" with no ill results. You should be fine.

 

[7schulz]

x2 on Mobil 1 Syn ATF no problems

 

[Tucknroll]

Re Changing the ATF:

You won't get 100% of the fluid out, but there is a much more efficient and less wasteful method than just draining, adding, and repeating.

I identified which cooler line (from the radiator) returns the fluid to the transmission, disconnected it (at the radiator), and then ran a piece of hose from the (now exposed) hose nipple (on the radiator) into a 5-gallon bucket.

i drained the transmission pan. You can remove the plug, or pull the pan and clean and replace (more thorough).

Refill the transmission pan, then start the engine, and start pouring in fluid (through the dipstick tube) while the engine is running.

The sump in the pan will suck up new fluid, pushing out the old fluid inside the transmission, through the torque converter, then out the transmission to the radiator cooler, and into the bucket.
(the disconnected hose will simply suck air during this procedure). This is the most complete exchange of fluid you can achieve, without a drain plug on the torque converter, which none of these TC's have.

You will want to have someone inside the car, shifting through all the gears while the fresh fluid is being pumped through. Stay in each gear for about 5 seconds.

You will find that after about 15 quarts of fluid, the stuff coming out will be clean fluid. You'll also find that it's difficult to keep up with the amount of fluid being pumped out. Just pour it in as fast as you can.

This procedure will replace most of the fluid inside the torque converter, and pretty much all the fluid inside the transmission. It's a very effective method and you can DIY.

Was it the upper or lower hose on the radiator that you removed?

 

[jcarter]

I agree with Cdan about the flush if neglected. We did a flush in our Sienna and it ruined the old tranmission (replaced with used). I just put a new hub & axle on the old corolla and the fluid looks & feels like old engine oil (thick, black, and gooky). I've got an urge to change transmission & brake fluids on all 3 toyotas. I will NOT be flushing. Enough about the other 2 Toyotas.

My 92 has been revving between gears (I think 2nd to 3rd) for years. To prevent damage, I make sure NOT to accellerate during this shift, but sometimes I forget. My plan is to drain, then remove the pan and clean all I can reach (comments?), then refill. I have a feeling this won't stop the revving, but may give me a few more years.