Transmission advice wanted

[econhonda]

So here's the deal:

I bought a 99 Limited 4X4 with an auto tranny about three months ago. It has 144,000 miles and runs great. I have been on the fence about how to service the transmission. The fluid doesn't smell or look burnt, but I would feed better about servicing it soon. I have no reason to believe that it has been serviced, but it very well could have. The previous owner kept up on other maintenance (timing belt, water pump, etc.). I've heard that doing a full transmission fluid exchange could do more damage than good on a transmission that hasn't been maintained properly. However, I don't really want to pull the pan, replace the filter, and only be able to drain 4 quarts. I know that by draining the fluid three or four times, the fluid would be pretty much new, but it sounds like a hassle. My question is, is the hassle worth it? What would you do? To flush or not to flush?

Also, I'm going to be towing a trailer from Salt Lake City to Bear Lake (1,800 ft climb in elevation) in August. The trailer weighs about 4,000 lbs. Is the tranny cooler a "must have"?

One last question, the front rotors are slightly warped. The pulsing isn't noticeable on a level road, but on a steep incline it will start pulsing pretty hard. Should I replace these before or after the tow? I don't want to trash a brand new set of rotors coming down Sardine Canyon, but I also don't want to be without full braking power

By the way, the trailer will have functioning trailer brakes.

Thanks for your help!

 

[JonK]

Purchased my 2000 SR5 in April of this year with 136K miles on it. I had the transmission flushed at a shop and had them put in Mobil Synthetic Auto trans fluid and have had no problems or issues. Also, I would recommend an external transmission cooler (especially if you will be towing). The OEM trans cooler is part of the radiator and these spring leaks over time. The danger here is that radiator coolant will mix with trans fluid and toast your transmission. Do a search on 'strawberry milkshake' and you will see what I mean.

My rotors were warped as well. Rotor replacement is quite easy ... ordered a new set of Brembo rotors from Tirerack and did OEM pads. Many here replace their front brakes with those from a Tacoma (requires rotors, pads and calipers), which you might be interested in since you tow.

 

[ryanr623]

Purchased my 2000 SR5 in April of this year with 136K miles on it. I had the transmission flushed at a shop and had them put in Mobil Synthetic Auto trans fluid and have had no problems or issues. Also, I would recommend an external transmission cooler (especially if you will be towing). The OEM trans cooler is part of the radiator and these spring leaks over time. The danger here is that radiator coolant will mix with trans fluid and toast your transmission. Do a search on 'strawberry milkshake' and you will see what I mean.

My rotors were warped as well. Rotor replacement is quite easy ... ordered a new set of Brembo rotors from Tirerack and did OEM pads. Many here replace their front brakes with those from a Tacoma (requires rotors, pads and calipers), which you might be interested in since you tow.

I second the tranny cooler. Just had the strawberry milkshake happen to me. Luckily ATF went into my coolant, and very little coolant went into the ATF. It drives and shifts great, but cost $900 to fix. And it could have been a lot worse.

 

[brian2sun]

I would do a full service to the tranny I it was mine. Drop the pan, replace the filter, then do a DIY tranny flush. If you're are hestitant about the flush, I would still do the pan and filter and then just do a couple of simple drain and fills (by pulling the drain plug on the pan) in the following weeks.

Tranny cooler is a very good idea.

People do Tundra brake swaps - not Tacoma. The Tacos' brakes are the same or even weaker than the 4runner because it's a lighter vehicle. You're probably fine using the rotors you have now, but it wouldn't hurt to change them. Also, turn the O/D off and use 2nd whenever you can. The engine braking will help a lot.

 

[pbcolt]

I am in the same boat. my 99 has 135k on it, and I will be doing something to the transmission on Friday (either a full flush or dropping the pan). According to the carfax, it has always been serviced at a Toyota dealer, which makes me think the transmission has been taken care of. I would just hate to get a full flush and have it hurt something....:shrug:

 

[shawnstcyr]

I spent 17 years as a mechanic. I always replaced the filter when I serviced a transmission. Ours are pretty straight forward to do. Especially since we have a drain plug. I would recommend changing that filter every 36 to 50k miles. As far as the flush goes, IMO, I would recommend doing it before I changed the filter. Doesn't seem right to put a new filter in there, then flush particles from your torque converter and cooler into it. But this area is just a matter of personal preference. Adding an aftermarket cooler will definitetly add a measure of insurance.

 

[brian2sun]

The only reason you may want to drop the pan and replace the filter first (before flushing it) is because you can get a solid 4-5 qts of the dirty fluid out right off the bat. If you don't get rid of this first, the dirty ATF will dillute the new ATF and it will take a lot more fluid to get it flowing clean and that just costs more.

I took the pan off 1st and in total used 16 qts - 4 to fill the pan back up and 12 to flush after that (it started running out nice and clean at about qt. #11). But if you don't drop the pan first and you let it slowly dillute 1 qt. at a time, my guess is you'll need more like 20+ qts. before it starts running out clean.