98 Transmission and differential fluid questions (1 Viewer)

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I'm planning to do a fluid change and I've been searching and reviewing threads and most I find apply to later 100s with a different transmission and LSD differential so I wanted to ask a few questions specifically about 98-99.

I think from prior threads I've confirmed that despite the manual and dipstick saying Dex/Merc this transmission should actually use Toyota T-IV fluid, correct? Does anyone know the capacity? I think the later 100 transmissions seem to be 12 qt, but I feel like I saw 16qt somewhere for the 98/99, is that correct? I was debating between Maxlife ATF and Toyota T-IV, I think I will probably do the Toyota fluid and add some lubegard. Probably going to drain via the cooler lines and fill via the dipstick 2-3 qts at a time.

For the differential I was planning to run 75-90W Mobil 1 gear oil in both front and rear, I don't really do any towing or anything, is there a different fluid or considerations required for the locking differential in the rear?

Also planning to do 75-90 in the TC, is that a good choice or is there something better?

Anything else I should be aware of in terms of variance from the later 100s for fluids?

Thanks in advance
 

reznunt

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My 98 owner's manual states Dexron III which is what I used. I think T-IV is for the 5 speed.

I run 75W-90 in the front, center, and rear locking diff.
 
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Valvoline MaxLife ATF is rated for Dex/Merc and Toyota WS, as well as others. Use that. You will not need that much, only a gallon. That's all that is going to drain out if that.

You can use limited slip fluid in a non limited slip application, will not hurt anything. BUT if you use a non limited slip fluid in a limited slip application the limited slip won't work, it will slip.
The limited slip fluid has friction additives that help the clutches to grab, that's basically how a LSD works, there are clutches, when they do not spin at the same speed they engage and lock the axles together.

I am using Castrol full synthetic gear oil in both diffs and t-case. I also replaced all of my drain/fill plugs with standard hex head plugs and threw out those POS Allen head ones.
 

flintknapper

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I wanted to ask a few questions specifically about 98-99.

I think from prior threads I've confirmed that despite the manual and dipstick saying Dex/Merc this transmission should actually use Toyota T-IV fluid, correct?

You can use Toyota T-IV if you like, or Valvoline MaxLife ATF or any of the most recent Dex/Merc offerings (they are all backwards compatible).

Does anyone know the capacity? I think the later 100 transmissions seem to be 12 qt, but I feel like I saw 16qt somewhere for the 98/99, is that correct?

Your A343F (dry) is going to need about 13 qts. If you are just going to drain the pan and refill then plan on about 4 qts.

I was debating between Maxlife ATF and Toyota T-IV, I think I will probably do the Toyota fluid and add some lubegard. Probably going to drain via the cooler lines and fill via the dipstick 2-3 qts at a time.

Either fluid will be good. Sounds like you plan on doing a full fluid 'exchange' using the transmissions pump?

For the differential I was planning to run 75-90W Mobil 1 gear oil in both front and rear, I don't really do any towing or anything, is there a different fluid or considerations required for the locking differential in the rear?

Nothing special needed for a locking diff. IF you had a LSD then a special lube is required. 98-99 model Land Cruisers had an 'optional' locking rear diff. Lexus LX470's of the same year models came standard with a Limited Slip. So if you have a Land Cruiser...then the Mobil 1 will be fine.

Also planning to do 75-90 in the TC, is that a good choice or is there something better?

You could run the same lube in your TC as your front and rear diffs.

^^^^^ expand for replies
 
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Thanks for the replies. I didn't know you could run either fluid dex/merc or T-IV, that is good to know. I do plan on doing a flush via the cooler lines so was thinking I'd get 3-4 gallons of maxlife or 12-14 quarts of T-IV. There isn't a big price difference between the two in the deals I've found.

As far as the dif I wasn't so worried about the LS vs non-LS, just didn't know if lockers required a thicker oil. 75-140 or something. I guess I'll plan for 75-90 all around unless I hear otherwise. @Spike555 , where did you get the hex head bolts? Are those aftermarket or are they from Toyota?
 
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I flushed my 98 trans. Used exactly 16 quarts. Valvoline Maxlife Synthetic ATF. 5 months or so ago. Shifts were buttery smooth right away. Probably have gotten even smoother after a few miles.

Edit: By “flushed” I meant
1. disconnecting the hose exiting the trans cooler.
2. starting the engine for about 10-15 second increments.
3. measuring the amount of fluid expelled and adding exactly that amount of new fluid back in the dipstick tube.
4. Repeating until the fluid ran clean.

This was at 285k miles.
 
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Thanks for the replies. I didn't know you could run either fluid dex/merc or T-IV, that is good to know. I do plan on doing a flush via the cooler lines so was thinking I'd get 3-4 gallons of maxlife or 12-14 quarts of T-IV. There isn't a big price difference between the two in the deals I've found.

As far as the dif I wasn't so worried about the LS vs non-LS, just didn't know if lockers required a thicker oil. 75-140 or something. I guess I'll plan for 75-90 all around unless I hear otherwise. @Spike555 , where did you get the hex head bolts? Are those aftermarket or are they from Toyota?

I ordered then oblind from a place in Australia, all of the fill/drain plugs are the same size. With shipping for all of them they were $60 if I remember right. I do not remember the place I bought them from, you could just go to AutoZone and buy them, just make sure the thread pitch is the same, but I bought 3 sets of them, each "set" came with drain/fill plug and washer.
Nice high quality brass plugs that a standard socket fits.
I wish I remember where I bought them from. You can just Google and find some.
When the dollar is strong buying from overseas is a benefit. When the dollar is weak it does not pay to buy overseas. I bought mine 2yrs ago, I had ot have our mechaninc at work get mine loose because the Allen heads were rounded. Now that is not an issue.

Australians LOVE Land Cruisers so all of the good parts and accessories are there.
If you're not sure they ship international just ask, most places do.
 
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I serviced my transmission last summer. The Toyota tech was very experienced and he told me that on a Land Cruiser transmission, drain out 4 quarts, add 4 quarts, drive 2 years and repeat. He didn't like the idea of flushing the transmission at all, so I went with his recs.
 
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I ordered then oblind from a place in Australia, all of the fill/drain plugs are the same size. With shipping for all of them they were $60 if I remember right. I do not remember the place I bought them from, you could just go to AutoZone and buy them, just make sure the thread pitch is the same, but I bought 3 sets of them, each "set" came with drain/fill plug and washer.
Nice high quality brass plugs that a standard socket fits.
I wish I remember where I bought them from. You can just Google and find some.
When the dollar is strong buying from overseas is a benefit. When the dollar is weak it does not pay to buy overseas. I bought mine 2yrs ago, I had ot have our mechaninc at work get mine loose because the Allen heads were rounded. Now that is not an issue.

Australians LOVE Land Cruisers so all of the good parts and accessories are there.
If you're not sure they ship international just ask, most places do.

Nice Find! I'm looking at their website, they have some neat stuff on here.
 
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I serviced my transmission last summer. The Toyota tech was very experienced and he told me that on a Land Cruiser transmission, drain out 4 quarts, add 4 quarts, drive 2 years and repeat. He didn't like the idea of flushing the transmission at all, so I went with his recs.

Is it ok to mix fluids if we're unsure what's currently in there? Looking at Valvoline Maxlife Synthetic ATF which was recommended above.
 
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You can also run a Dexron VI fluid. Dex VI is backward compatible with Dex III but incorporates the latest in synthetics and additives. Although my 100 currently runs on Amsoil I have had Dex VI in my 99 Camry's Dex III transmission for the past 100,000 miles with smooth results.
 

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