2003 Tundra/ 89 Skamper 080S inbed popup. questions about transmission fluid flush

[tundracampin]

Got a 2003 Tundra SR5 V6 3.4L that has recently taken us to from Montana to Alaska and back again. Many other trips besides that one but that was the biggie. We often tow a raft trailer behind and during the winter the camper typically comes out and we tow a single sled trailer and keep one sled in the bed.

Why I am here. Well, mostly to brag about the truck I love. But also for one very specific question. Three times in the last year and a half my A/T oil temp light has come on. Once pulling my sleds up a steep icy road in 4WD. The second time was going up a much steeper road in the spring with the camper and pulling a raft trailer. (that road was rough enough to break my passenger side leaf spring and put it into my tire, but thats a different story) and the third time was driving up a rough slightly steep dirt road for 8-10 miles.

So I checked my automatic transmission fluid and it seems to be a bit brown and smell just a bit burnt. All the forums I have read and people I have talked to have had very differing opinions. Should I flush and refill or should I just run it and leave it and wait for a tranny rebuild. Y'all be the judges. Hopefully at least a few of you tundra nerds have dealt with this before.

If your interested in what mods I've got or what I'm working on I'm happy to put in the details, but also I'm just worried about not killing my transmission and getting stranded some where sketchy.

 

[Toyaddict]

I've read the back and forth of flush vs drain and fill vs letting er' eat etc. For my vehicles I do a filter change and drain and fills.

Whatever you do a bigger transmission cooler should probably be on your list. Maybe one with a dedicated electric fan, seems like your troubles are low speed high load conditions. The clutch fan may not be providing adequate airflow for the trans cooler, the increased coolant temperature heating the trans fluid in the rad likely isn't helping things.

 

[Mrmrswelch]

I've always been a fan of the full flush. Get fluid to Normal Operating Temp, check level. Remove the outgoing line from the cooler into a bucket with ability to measure the amount coming out. Turn truck on at idle until fluid pours out. After 4ish qts come out it will begin to spit, turn truck off. Refill with exactly what came out and repeat process until fluid is red, about 16 qts. Check fluid and adjust as needed. The pickup screen replacement in the pan is uneconomical and unnecessary because it's not so much a filter as it just keeps larger items from being sucked up into the fluid pump if something goes wrong in the transmission. The magnets in the pan actually do a better job filtering then the pickup screen does. I've actually been thinking about installing an external spin on filter on mine for quick changes and actual filtering capacity.

 

[tundracampin]

I've always been a fan of the full flush. Get fluid to Normal Operating Temp, check level. Remove the outgoing line from the cooler into a bucket with ability to measure the amount coming out. Turn truck on at idle until fluid pours out. After 4ish qts come out it will begin to spit, turn truck off. Refill with exactly what came out and repeat process until fluid is red, about 16 qts. Check fluid and adjust as needed. The pickup screen replacement in the pan is uneconomical and unnecessary because it's not so much a filter as it just keeps larger items from being sucked up into the fluid pump if something goes wrong in the transmission. The magnets in the pan actually do a better job filtering then the pickup screen does. I've actually been thinking about installing an external spin on filter on mine for quick changes and actual filtering capacity.

You think pulling the transmission pan and givin' her a scrub is a good idea to get all the metal filings out? and if I'm in there might as well do the filter anyway eh? Appreciate the play by play for the flush too.

 

[tennesseewj]

I am a fan of new fluid. I would also consider pulling a sample of the old fluid and sending it off to Blackstone Labs or somewhere similar. If you have excessive metal shavings or other signs of impending doom, it should show up in the report.



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[Buddha.]

Heat kills transmissions.
Drop and fill. Maybe add a trans cooler. Maybe add a actual trans temp gauge so you can monitor it more closely. Check to see that your radiator isn’t full of debris/bugs.

In the situations where the temp light came on where you In low range? Should you have been? I mention this because many lifelong truck owners don’t know what low range is for and don’t use it. Low range will make things easier for the transmission, in situations where you can use it.

 

[tundracampin]

Heat kills transmissions.
Drop and fill. Maybe add a trans cooler. Maybe add a actual trans temp gauge so you can monitor it more closely. Check to see that your radiator isn’t full of debris/bugs.

In the situations where the temp light came on where you In low range? Should you have been? I mention this because many lifelong truck owners don’t know what low range is for and don’t use it. Low range will make things easier for the transmission, in situations where you can use it.

I was not in 4low any of these times. 4high one of the times and just 2 wheel the others. Does going slow up rough roads require 4low even when traction isn't necessarily an issue?

 

[Buddha.]

I was not in 4low any of these times. 4high one of the times and just 2 wheel the others. Does going slow up rough roads require 4low even when traction isn't necessarily an issue?

In my opinion selecting high vs low range is not about traction. It’s about having more power and control at lower speeds. In fact sometimes it can be useful to have low range 2wd.
The only off roading I do is moving heavy trailers around fields etc for farm/firewood work, no more than ~20mph. In these scenarios low range helps the trans not work so hard.
Low speed driving on rough roads would benefit from low range IMO.

 

[tundracampin]

In my opinion selecting high vs low range is not about traction. It’s about having more power and control at lower speeds. In fact sometimes it can be useful to have low range 2wd.
The only off roading I do is moving heavy trailers around fields etc for farm/firewood work, no more than ~20mph. In these scenarios low range helps the trans not work so hard.
Low speed driving on rough roads would benefit from low range IMO.

Awesome thanks for the info

 

[blueranger501]

Full flush I don’t buy the lifetime fill argument. Well I do, trans will last the lifetime of the fluid which will get dirty and break down over time not providing proper lubrications. All my rides have shifted better after a full flush, no explosions. If you want to ease into it drain the pan only and refill with that amount. Así consider a scan gauge so you can monitor other temps as well including water. Mine does water, intake air temp, volts and will be programming for trans temp

 

[Mrmrswelch]

You think pulling the transmission pan and givin' her a scrub is a good idea to get all the metal filings out? and if I'm in there might as well do the filter anyway eh? Appreciate the play by play for the flush too.

It wouldn't hurt anything, and honestly it will let you know if anything else is going wrong in the Trans.. I.e. Larger particles stuck to the magnet. I would install the OEM pickup screen as I don't know if the aftermarket ones from NAPA or otherwise are at the same micron equivalent. I would also look at a fluid that is synthetic and backwards compatible with the Dex III or if you have ATF WS (Toyota synthetic) stick with OE fluid or Idemitsu (NAPA/Advance carries it) if you can find it.

 

[NorthLandExp]

I would also recommend checking out and possibly replacing the radiator. Those 3.4L v6's are known to have the dreaded milk shake problem if the radiator goes. It was the only thing I didn't replace on my 3rd gen 4runner and that transmission quit after the radiator went. Same issue with it overheating a few times under load before it finally quit. The 4runner and taco forums have a ton of info on independent transmission coolers which will negate any cross contamination of fluids.
On another note how do you like the 080 Skamper on the back? Ive got a 2003 4.7 Tundra and would love to find a pop up like that, but was curious how they handle the weight?

 

[bkg]

flush and fill... add external cooler - likely bypass the radiator cooler.

 

[toastyjosh]

This is for a 3rd gen 4 runner but same engine, so same applies to your rig. Make sure you change the fluid and filter. Also would be a good time to check the transfer case fluid.

Installing transmission cooler in 3rd generation **Pictures!**

I decided to do a write up for the transmission cooler. Transcoolers are very important in 3rd generation 4runners to avoid the pink milkshake issue....

www.4runners.com