OK, I want some more info, I know hot = bad, but how hot, how bad is bad etc.
Background info: My 4runner is a 4speed, I spend a lot of time on FS roads. The tranny will ONLY lock the TQ in OD and 3rd if shifted into 3rd. Not in second unless in 4lo. This limits me to 25 ish MPH.
Of course it wants to hunt around between 2nd and 3rd a lot on these types of roads and my trans temps get hot.
I have a scangauge that reads it, but i dont really know when its TOO hot. I have been meaning to install an external cooler but have not done it yet. I'm thinking I may let it pump out the old fluid while I have the line disconnected, but not sure that really worthwhile wihtout dropping the pan and changing the filter. I have 212k on the trans and Id really like it to last. It's "lifetime" fluid, but I don't particularly believe that, its looking pretty brown now.... I haven't changed it, and I have no idea if the PO did. Im guessing not since its 'lifetime' fluid and all the service was done at the dealer.
Learn me!
I just did a drain and fill on a new to me 95 4Runner with an auto. I initially put the plug back in after I started draining it, I thought I was draining the oil it was so bad! This one has 243k on it and it was shifting fine, just changing all fluids as usual.
As far as temps go, there is a sliding scale as too cold is bad as well. I always shoot for 150-200 as taken from the fluid out line from the transmission before any cooler. I used to see them spike to 230-235 on long climbs in the desert in the summer and start to come right back down once the hills where crested. These are from various vehicles, none the Toyota, but I believe these to be pretty standard numbers.
I'm told 180 is ideal, past 220 is concerning. You can obviously go a little hotter with synthetic, I like Valvoline maxlife.
It runs right around 186-190 locked in OD cruising on the freeway. But stop and go and it spikes in a hurry! Its toyota fluid, no idea if its synthetic or not. Keeping it under 200 would be nearly impossible.
I had the idiot light come on once, before I had the scangauge, and I have seen 275 before and the light wasn't on. Its easy to get to 240-265 just cruising up FS roads. (its not exactly flat around here) I try to find slow sections to drop to 4lo, but its a pain sometimes.
Just grabbed a fluid color sample for you fine folks. Not so red anymore.
Yeah, do a pan drop and add an aux cooler on the trans out/cooler in line. Unless you get spendy with a thermostatic cooler you always want the fluid running through the oil-water cooler in the radiator last, keeps the fluid warm on cold days.
In reply to Kenny_McCormic:
Pan drop required just because of the nastiness of the fluid? I really don't want to drop the pan in nasty weather in my gravel driveway... It has a drain plug.
In reply to java230:
If there's a filter in there, it's a good idea to change it out. Also to wipe the layer of grey goop out of the bottom of the pan. The fluid doesn't look that bad, but that's something that you should change preemptively for best results.
If it has the slightest bit "burned electrical" smell it's shot, regardless of color. The frictions on the clutches and bands are very sensitive to wear once the fluid's additive package is burned away. External cooler in series with the built-in radiator cooler is ideal, as it allows the fluid reach operating temp quicker but keeps it under 200*F after that point. Rebuilds are horribly expensive if you don't have the formal training/experience and tools/facilities to DIY.
Kenny_McCormic wrote:
Yeah, do a pan drop and add an aux cooler on the trans out/cooler in line. Unless you get spendy with a thermostatic cooler you always want the fluid running through the oil-water cooler in the radiator last, keeps the fluid warm on cold days.
That's a bit of an old school issue with tube and fin coolers..
stacked plate type of coolers are ment to go after the cars rad or replace the rad cooler all together. They are a better type of cooler to get. Tru cool coolers are the ones I like best. .
Thanks guys
In reply to WildScotsRacing:
No smell, but I'd like to keep it that way.
Is it worth paying a shop to do? I have a gravel driveway and it rains a lot this time of the year. If it was just draining the fluid I could do it, but I'm not sure about dropping the pan and dealing with the filter.
java230 wrote:
Thanks guys
In reply to WildScotsRacing:
No smell, but I'd like to keep it that way.
Is it worth paying a shop to do? I have a gravel driveway and it rains a lot this time of the year. If it was just draining the fluid I could do it, but I'm not sure about dropping the pan and dealing with the filter.
Yes, have a shop do it. A power flush machine will get about 95% to 98% of the old fluid out because it cycles it through the torque converter. Doing just a pan drop in the driveway is only good for at most 1/4 to 1/3 of the fluid.
This just got bumped to the top of the need to do list... I found out what temp the idiot light comes on at, its 300.
Why can't you just lock up in second transmission?!
Thoughts on this unit?
http://www.amazon.com/Hayden-Automotive-679-Rapid-Cool-Transmission/dp/B000C3BBKS/ref=sr_1_4?s=automotive&ie=UTF8&qid=1449858095&sr=1-4&keywords=transmission+cooler
WildScotsRacing wrote:
java230 wrote:
Thanks guys
In reply to WildScotsRacing:
No smell, but I'd like to keep it that way.
Is it worth paying a shop to do? I have a gravel driveway and it rains a lot this time of the year. If it was just draining the fluid I could do it, but I'm not sure about dropping the pan and dealing with the filter.
Yes, have a shop do it. A power flush machine will get about 95% to 98% of the old fluid out because it cycles it through the torque converter. Doing just a pan drop in the driveway is only good for at most 1/4 to 1/3 of the fluid.
It's true that there is a lot of fluid that doesn't drain when you just pull the plug or pan. But I've heard more than one story about a trans going south shortly after a flush or other "advanced" cleaning method.
I'm not saying they're bad but seeing as trannies can last a quarter million miles with no fluid change, all I would ever do is drain, replace filter and clean the inside of the pan.
To get all of the fluid, I'd just do a series of oil changes and finish the last change with a new filter.
OK bringing this up again so as not to start a new thread.
I have a cooler im hoping to install this weekend.
Toyota does a 'flush' that uses only the TQ's pressure to exchange the fluid. I does not use an external pressurized pump, from my reading this is what seems the cause "flush issues". They also use their nifty computator to open all the VB passages.
Dropping the pan changes 2-3 qts, it holds ~12. Do I really need to change the filter? Its just a stainless screen from my reading, seems like it just keeps big chunks out. If this is very important to change, my thinking is install the cooler (losing a little fluid im sure) drop the pan, change filter and refill. Take it have have it fully flushed. (Its $210, me buying fluids is ~100)
I'd really like to avoid dropping the pan if i can. But i want to keep the truck for another 100k, its at 215k now.
On my Montero, I dropped the pan and refilled with fresh fluid there and put in a new filter. Then, pulled off the line to the transmission cooler and started it up while watching the line (used some clear hose). Shifted through each position for a few seconds, then stopped when the transmission fluid started looking new. I got nervous and stopped partway through to add more transmission fluid, but probably didn't need to. Refilled with fresh fluid and called it good. Maybe you can do something like this? Check forums and see if your transmission will tolerate it.
Edit - 10 second search shows that you should be able to, probably smart to top off fluid while pumping out the old stuff - maybe add in a quart after you guesstimate you've pumped out a quart. And if you have never had the fluid changed, I'd drop the pan to make sure the filter is good - mine was perfectly clean but it's had regular changes every 60k miles. Despite this, there was still fair amounts of magic automatic transmission sludge to clean off the bottom of the pan.
Yes its been done that way on my truck before, but the write ups i read said to do a couple quarts at a time, pump two out, put two fresh in etc. Sounds like a huge PITA!
Sludge doesnt sound good, I guess i should just man up and do the pan drop. Just raining a lot this time of year, and gravel driveway....
java230 wrote:
Yes its been done that way on my truck before, but the write ups i read said to do a couple quarts at a time, pump two out, put two fresh in etc. Sounds like a huge PITA!
Sludge doesnt sound good, I guess i should just man up and do the pan drop. Just raining a lot this time of year, and gravel driveway....
At least it's had the fluid changed before, you're doing better than 95% of people so far :-)
I'm the type of person who would worry about what the transmission looked like if I hadn't dropped the pan, especially on four wheeling trips. If $110 to a dealer seems reasonable, take it in!! I'm just a cheapass. I bet they do what you would do at home, but having a lift makes their lives easier 
In reply to Brokeback:
I'm not sure its ever been done.... I dont remember If I did it at 120k service....
The dealer doesnt do the pan with their flush.... I have to do that part if i want it.
Otherwise yeah at some point $110 for someone else to deal with the fluid isnt all that bad. Im cheap too, but changing two quarts at a time with a cobbled together setup doesnt sound fun....
java230 wrote:
In reply to Brokeback:
I'm not sure its ever been done.... I dont remember If I did it at 120k service....
The dealer doesnt do the pan with their flush.... I have to do that part if i want it.
Otherwise yeah at some point $110 for someone else to deal with the fluid isnt all that bad. Im cheap too, but changing two quarts at a time with a cobbled together setup doesnt sound fun....
Ah, so if you wanted the pan cleaned and filter replaced gotta do it yourself. Or pay more!!
I think the whole shutting down and filling up isn't completely necessary, especially if you have a helper. I did it by myself since the fluid doesn't pump out too fast - keep a funnel on the fill tube and add in as you pump out.
In reply to Brokeback:
Yeah exactly.
Doesn't come out fast?? Im surprised by that. fill tube is like a 3/8" hole, thats hard to get fluid down quickly. Maybe ill wrangle the wife to help 
still a nasty project in wet gravel.... Doesnt fit in the garage sadly.
IIRC its Dexron 4, should i stick with that or go higher number dexron, full synthetic? Toyota wants you to buy their fluid of curse....
As mentioned before, Valvoline Maxlife is good stuff, full syn Dex VI, pretty cheap too if you buy by the gallon at Meijer/Walmart.
In reply to BrokenYugo:
Are all the dextron's backwards compatible? ie ok to use 6 when 4 is spec'ed.
There is no Dexron 4 (jumped from 3 to 6) but yes AFAIK Dex 6 supersedes all the way back to the pre Dexron (1968) "suffix A" stuff. There is a Toyota type 4 fluid, which Maxlife claims to cover.
java230 wrote:
In reply to Brokeback:
Yeah exactly.
Doesn't come out fast?? Im surprised by that. fill tube is like a 3/8" hole, thats hard to get fluid down quickly. Maybe ill wrangle the wife to help still a nasty project in wet gravel.... Doesnt fit in the garage sadly.
IIRC its Dexron 4, should i stick with that or go higher number dexron, full synthetic? Toyota wants you to buy their fluid of curse....
Ah, you got a sissy fill tube mine is closer to 3/4" at the top. You may be forced to run for 15-20 seconds then stop and fill it back up.
In reply to BrokenYugo:
ah ok, its the Toyota type 4 then i guess. I used the maxlife for the PS fluid, with no issues yet.
Thanks!
In reply to Brokeback:
Yeah.... Well mine is the last year with a dipstick/fill tube at least!
