Proper method to swap out transmission and diff fluids

[north]

Hi,

I am hoping to get new fluids into my 4wd wagon before winter arrives in the Great White North. I have read all over the forum to be sure to do this in the correct method but am unable to locate a thread which breaks down the correct method. Does anyone have a link or could direct me to a useful spot. I do have a FSM I can follow and am planning to run synthetics as the winters here are very cold and it appears the seals are ok.

I have access to a lift which should make life easier and am planning to tackle it this weekend along with a few other odds and ends.

Thanks,
Andrew

[xirdneh]

the FSM does this (car is raised and level)
1. on bottom of tranny there is a 19mm hex bolt that needs to be loosened and backed out 8 full turns
2. remove two bottom plugs (front and back) 24mm/15/16"
that will get it to draining
3. remove 24mm/15/16" plug on driverside just aft of left CV axle (where axle enters differential ..aka transaxle housing)
5. remove 24mm/15/16" plug on passenger side of tranny its the third plug back , first is 19mm (do not remove), second 1-1/16" with wire coming out of it (do not remove), third one is hard to get, between exhaust pipe & tranny is tight. i use a 15/16" combo wrench. make sure you get a good grip on hex head so you do not bugger up the head. flattening (12 or 6 point) the box end of the wrench can help get better grip
after its done draining
5. install two bottom drain plugs. these are magnets so clean off debris first
6. fill from passenger side (third plug back) hole
i used a gear oil pump with a small 90 deg fitting on the end made from some pipe or tubing fitting
pump till oil overflows and then let it rest for 15 minutes then pump some more (repeat)
its full when oil comes out of driverside hole (see#3)
7. install and tighten all 24mm/15/16" plugs and 19mm hex head that was backed off 8 turns

capacity is 1.1 gallons 85-90 wt gear oil
some on this site recommend 3 parts 85-90 wt range gear oil 1 part synthetic

there are other methods in "repair guides" on this website

[ARCHINSTL]

FIRST - REMOVE ALL 3 FILLER PLUGS ! ! !
Reason being is that these are softish metal and someone, over the last 30 years, may have boogered the flats. You do not want to drain the lube and find out the filler plugs are unable to be removed, save with a BIG Vise-Grip!
See viewtopic.php?f=10&t=6976
Tom M.

[north]

Thank you!

[JDNightFox]

Is there a difference between using 75-90 and 85-90? And regular/synthetic? I have a good deal on Royal Purple 100% synthetic 75-90 and I thought I could change it out with full synthetic

[Petros]

I ran Royal purple in my high mile trans and found several issues: the stuff is too slippery for worn sycros, they depend on friction to work (each shift suffered gear clashing like the sycro was gone), and it was leaking from all of the seals. So I ran 50/50 mixture of synthetic and regular gear oil (I think I used 85w-90), and it worked perfectly, still running it today.

The trans was designed to run on single weight gear oil, if gear oil is changed on 30k mile interval per the service manual, and the trans is not abused (adolescent "speed shifting" and similar abuses), it will almost last indefinitely, even using regular gear oil.

trans life is actually pretty good even with poor maintenance and abuses. issues occur because leaky seals are not fixed, and it runs low or without gear oil, or if gear oil is not changed over the life of the car, which is usually the case.

[north]

Would driving it in colder winter conditions change the effectiveness of the synthetic vs the regular gear oil?
I am planning to change it soon and might do the mixture as recommended.

[Petros]

only right after you start moving when the gear oil is really cold. Mine is hard to shift right after pulling away from a cold start on sub freezing days, I double clutch it. Usually goes away within a block or two of driving.

[cromagmom]

Is it OK or even possible to fill from one of the driver side fill plugs? I mistakenly didn't check the forum out before draining the fluid and my passenger side bolt is seized/rounded. I want to take it to a shop to see if they have better ways of getting that out, and it would be possible to push it over, but it's far enough that I'd rather not have to do that.

[Petros]

I fill it from the left (drivers side in north America) side of the front diff housing. It is right next to where the front CV axle plugs into the front diff. You can get a full socket on it with a long extension out from the wheel well (if you remove the driver's side front wheel), or crawl under the car to reach it. There is a lot more room to work, and you are less likely to strip or damage the plug since you can get both hands on the wrench to steady it and keep it aligned.

It only issue is that it takes longer for the gear oil to get from the front diff housing all the way back to the main gear box and transfer case. I like to heat the jug of gear oil (put it in a large pan of hot water on the stove), and than hang it from the hood or engine compartment, and feed an extension tube into the front filler plug. They sell the filler spout at Wal-mart and most auto parts stores for only a few dollars, it comes with a 12" long clear flexiple tube, I put a 3 ft long one on it so I can work from the engine compartment.

You have to keep an eye on it that you get all 4.1 Liters into it, and it does not back up in the front diff housing and start spilling out onto the floor (if the gear oil is cold it moves so slow it tends to back up in the front housing).

The front diff housing, main gear box and the rear transfer case all all internally connected, but the openings between them is not very large and you have to to fill it slowly so the gear oil had time to get all the way back to the transfer case.

also, remember to back off the center plug 7 or 8 turns, it allows the gear oil to spread to the rear of the housing faster.

I tried once to use the filler plug on the right (passenger) side of the gear box case and gave up on it, the access is too tight and difficult. So I always fill from the left side front filler plug, I also jack the car up from that side and with the front high so it allows a few more oz. of gear oil into the transaxle assembly.

[Petros]

Here is a "Hopkin's oil filler spout" that I use, there are other brands too. They do not cost much and it beats laying on my back using a plastic oil pump to get over a gallon of gear oil into the transmission (a real PIA!).

[Jonymoto]

Yes, you can fill it from the driver side fill plug (LHD Tercels). There is one plug just behind the differential. Another thing, I normally remove the 19mm bolt that is loosened 8 turns completely when draining the gearbox. I find I get a bit more oil out by doing this. But put it back in and back it off 8 turns to allow oil to fill the rear section of the gearbox when you fill up the gearbox. Here in Australia I just use regular 85w90 oil as we don't have the cold temperature issue. Also use GL4 oil if you can as they say that GL5 can erode the synchros. I don't know how severe this is. I've had my Tercel for 32 years and I've always used GL5 oil until recently, but I change my oil every 12,500 miles (20k kms). Try removing the damaged passenger side fill plug with a vice grip or hammer and blunt chisel. Then replace the plug with a standard M18 hex plug. You should be able to buy these from a parts shop. They should have a bigger head than the ones fitted by Toyota.

[jaydee911]

Well 1st off thank you guys for the info.
2nd I really wish I had read this befor I went ahead and replaced the oil it would of saved me a head ache.

I used the photo attached as a reference and it showed the fill plug near the rear of the trans. It was confusing to me because that fill plug was only 2 or 3" above the drain plug it described.

Anyways it took some time but I managed to gravity feed 4l of fear oil in there with a funnel and hose. Wasn't the best method I lost about 100 ml doing so.

My question is. By useing the "rear" drain plug do you think I will have any issues with the gear oil getting to the right places? And I also noticed the drain plug I removed diddnt have a magnet attached.

THANKS AGAIN THIS GROUP ROCKS!

[Petros]

as long as you got 4.1 quarts in it, you should be fine. YOu can check the level by inspecting any of the filler holes.

Several things I noticed on this FSM procedure, its says to fill until it comes "out of the filler holes" note the plural, implying all of the filler plugs should be removed, yet they do not tell you to remove them. Also, it states use either GL-4 or GL-5 gear oil, there was a concern the GL-5 additives may harm the syncros, but apparently the FSM is not concerned with that issue, perhaps the internal parts are all compatible with GL-5?

[Jonymoto]

Sorry I forgot to attach photo.