Will a transmission flush replace the fluid in differential?
 

Hopefully someone can answer my question. Im looking to do a tranny flush on my 97 with 175K. I last did a drain-refill three times 20K+ miles and 3 years ago. The fluid is currently dark so being thorough that I am I plan to do a flush by connecting to one of the AT cooler lines, after dropping the tranny pan of course. I'm wondering if this flush will also replace the fluid in the differential or I still have to drain it separately. The tranny shifts fine for its age. The current fluid is Toy II/III and a little pricey (~10/bottle from local Toy dealer) but I plan to keep it the same.

Really appreciate any help.

Fluid is shared with the differential. However ATF tends to sludge up/pool at the bottom of the diff and won't come out when doing a flush through the cooler lines. $10/quart is pricey for a bit more you could move up to Royal Purple ATF which works brilliantly in these cars.

basically no.

There is a fill and drain plugs specifically for the final drive. the above is also correct, it is a shared pool over all but there's a ridge inside so draining is different.

^^ Good way to put it. The first version of the A540E did not share any fluid (pre 1992) after that yes. The situation evolved to where I believe the last versions of the A541E only had a drain plug for the diff no fill. Best practice is to drain the diff, if there is a fill plug then use it.

Thank you Lexus2000 & ES300NZ for replying.

I heard good things about Royal Purple but that's too rich for my blood. The two alternatives I was considering were Toy T-IV and Valvoline Max Life. The general consensus over to toy nation was a No for T-IV in place of Toy Dexron II/III. The Valvoline Max Life seems OK but I'm not totally convinced.

I gathered that a special tool needed to get to the differential drain plug due to how tight the access is. Any of you happen to know what the tool is? Thanks

Amazon has 6 quarts of Royal Purple for $77 not sure about shipping. RP can be used longer so in reality cost is not much higher if at all. I have never been a big fan of Maxlife other people seem to love it, if you want to go inexpensive this is a decent fluid

Absolutely do not use T-IV.

...oh on the tools if memory serves the diff fill plug is 17mm bolt drain 10mm hex. Attempt to remove the fill plug first (if there is one).

Yup you can also use the wally brand DexIII / mercon V fluid. Both 10mm hex or T55 torx work for the plug.

Thanks, guys.

- My understanding is I don't need to worry about the differential fill plug because the I can just fill via the dip stick hole. Is that true?
- I read somewhere that a regular hex would not do because there's so little room. There's a need for a flex head or some small hex?
- Here's the ATF part number I use: 00718-ATF00. My understanding is this is for Toy Dexron II/III. One post I read got me confused. It says 00718-ATF00 is for Toy Dexron II. It implies there's a different part number for Toy Dexron III. Can some one clear up?

Thanks.

Well I guess you "can" use Dex II but recommended is Dex III. If you look at the dipstick it might say "Dextron II/III" but the manual will say Dex III. OEM is always fine, but I stopped using OEM long time ago.

I use the hex socket (el cheapo from Harbor Freight) or T55 socket. You can use any extension length you want on your ratchet. Regular L shaped hex tool is a bit difficult. I normally put the socket on standard size ratchet and use my 18 in cheater pipe lying on the floor. You can use the socket on breaker bar if you have one (I do but it is not ratcheting). I do not lift the car or put on ramps. ATF fill via dipstick hole using the long black funnel.

Right, both on the stick and the manual call for Dexron II or III. And I'm all for Toy Dexron III by itself if there's such thing and I would like to know the Toy part number for that.

I was doing alot of things at once so I didn't specifically notice, but I do remember is was unreasonably tight, and I think it was a hex tool, I had to use a power bar on it to get movement, but that doesn't mean you'll have the same experience. Pretty sure fill and drain were different.

Can someone do me a favor and quickly confirm there is or isn't a differential fill plug for the 97 es? First, through my research, I thought I can fill the differential via the dipstick hole but now I'm confused. I'm in a middle of the job and it's dark outside :). Thanks a lot.

I can confirm that the differential is shared with the rest of the transmission, you are ok with filling from the dipstick.

Appreciate it, DJPsystems. while under the car I had seen what appeared to be the 17mm fill plug (with gasket) for the differential and wasn't sure. Plus a few older posts I found on this forum stated using a fill plug for the differential. A quick check of filling from the dipstick hole and seeing fluid coming out of the differential drain plug was assuring. I was so ready to bike :) to a near by Walmart to pick up this inexpensive but good reviews pump https://www.walmart.com/ip/16351021

BTW, I used this extender to help loosen the differential drain bolt . I recently bought it but wasn't convinced of its worth and effectiveness (and wanted to return). Gave it a try and it did work beautifully. It's hefty and well built.