2006 transmission issues

I'm thinking of purchasing a 2006 Tundra V8, 4wd. I'm told by the previous owner that the radiator leaked water into the transmission and basically, when it gets hot, it stops working. Was advised that I would need a new transmission and some way to cool the transmission without using the radiator. Does this make sense and can it be done?

 

Pink milkshake happens. The transmission lines pass thru the radiator, and when the radiator gets old, fluids mix.

I think much of what he said is bullshit on that last bit, or I'm not understanding it. The first course of action would be to fully flush the transmission and get clean Toyota WS fluid into it. The transmission is sealed on the 2005-2006 model year, and requires WS fluid specifically (not "ATF" or "T-IV" fluid).

 

PS @jfmg1957 there may be other stuff you missed.

Read the first two replies of this thread before you invest any money: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

So many people make bad purchases before reading that thread, and we see a lot of "OMFG HELP!" first-posts on here, which is why that thread exists: We got together and outlined all the critical shit people need to know when buying a 1st gen Tundra.

 

Thank you for your response. Here's the question I have about the frame. Is there any amount of rust, other than surface, that is tolerable? The truck I'm looking at has 279,000 miles on and did "live" in Colorado for 8 years and then came to Florida.

 

It's super easy to post pics on here. I highly recommend doing so.

We often see colorado trucks with mild rust on here. It seems like Utah has more salt they use or something, because utah trucks always look worse.

The thing is, sometimes the rust hides in weird places. And sometimes, with Florida as a good example, anglers like myself, some of which who may fish in brackish or salt water and launch their boat with the truck, may have really bad axle housings or even the frame from the gas tank back.

We expect to see some rust on Colorado trucks. As long as it's just surface, and tapping is clean with a hammer, and you don't see perforation or delamination (sheaving) in the known-bad spots (especially hidden spots like the x-member above the spare tire, and behind the splash guards on either side of the front springs), chances are you're OK.

All that said because I can't just say, "Yeah, some rust is OK". We've seen really damn clean frames with holes straight thru the frame up front, where the frames like to snap. I think I linked up one such pic in that thread.

 

Curious question, something that has lived on my mind since getting this truck: What is the design of the pass through line for the transmission fluid inside the radiator? The bottom of the radiator has the inlet and outlet ports for the trans fluid, but im unsure what the internal design looks like. In my head, there is a solid metal piping that runs through the bottom plastic of the radiator carrying the fluid from one port to the next, and is surrounded by the coolant which cools it. I ask this to learn which part of the system would fail that allows the mixing of the fluids.

 

@tvpierce showed a good example of the internals here: https://www.tundras.com/threads/transmission-heat-exchanger-line-leak.151831/#post-3784755

The part that fails is in his 3rd picture, it's where the nipple fitting connects to the long rail passing thru the radiator lower housing/cap.

And that pass-thru does serve a function: It helps bring the transmission fluid up to temp more quickly, for optimal operation.

 

You're the GOAT, thank you , I can now rest.

I wonder then on what the comfortable life is on the radiators are, just like the LBJ's. I live in Texas, truck has no rust luckily. The radiator is 10 years old but still looks great, I just cant see what the inside looks like.

 

At minimum, based on what I've seen here for failure, I would replace the radiator at least every other timing belt/water pump/tensioner/pulley job using the Aisin kit (ending in p/n "-021").

That timing belt/etc. change should be happening every 90k/9yr per Toyota, though it seems safe to wait 10yr/100k miles **IF** you use OEM parts (half the frequency window if you're adamant about using aftermarket parts ... Aisin is the OEM supplier, and is designed for at least 9yr lifespan). Some people had way more miles than that on the original factory belt, but it's a bad idea with the V8, being a low-interference engine and all.

That said, when you realize the radiator is like $120-140 bucks if you buy through RockAuto, or get it pricematched to RockAuto thru Summit Racing's site, you really need to ask yourself: Should you really not just change it along with the timing belt?

As it is, the other big thing to factor in here is, Toyota also recommends flushing/replacing the coolant every 5yr/50k miles **IF** you use the correct pink colored SLLC coolant. Maybe a good in-between for people concerned about budget is to change 5yrs/50k after the timing belt was done? Basically, every 1.5 timing belt/etc. changes? Failure to use the correct color coolant can lead to buildup/clogs in the system ("universal" coolant is bullshit, marketing), and failure to change on interval can lead to head gasket failure.

 

Well said. I have ptsd with changing the coolant on this truck as I have needed to do it so many times already for multiple jobs: Timing job, replacing junk screw hose clamps with factory clamps, replacing the figure 8 oil cooler ring, and most recently while changing the cam seals. Each job requiring draining the coolant so I am just jaded to needing to unplug another coolant hose. The last things I can imagine I will need to do that will require me to drain the coolant is changing the radiator and the starter since some hoses need to be disconnected. I would love to do both at the same time to avoid 2 more coolant drains but the starter is much more involved and is still in good working order.

 

I mean, in all honesty, they make hose pinch clamps, even for the larger hoses. The radiator only holds, what, like 1/3 of the coolant in the system? Clamp off the trans hoses, the rubber hoses, drain and pull the radiator. Attach the hoses to the new radiator, fill it before removing the hose pinch clamps, remove the pinch clamps, and with the nose of the truck up, burp it using a burping kit. Go back to flat ground and follow the standard process to top off the transmission fluid, after getting up to operating temp, which it should be at/near after burping.

 

Only hoses needing disconnected for starter replacement are the two to the throttle body. You can drain radiator from drain cock and get about 1.5 gals. I used a funnel and a couple of old washer fluid bottles to collect that. When I did my starter I replaced to metal/rubber gaskets at the four corner crossovers and only spilled a small amount in the valley. Don’t sweat coolant drains and radiator replacements.

 

Oo true, 100% this sounds like the move, great idea thanks!

Wish I did this back when I bought it while doing the first timing job. I used your guide back when buying and did the timing job asap, just didn't think to also do the radiator.

Thanks man!

 

I agree, after doing the cam seals every other job seems simple in comparison. My hatred for coolant comes from when I changed the oil cooler ring. I undid the drain cock all the way and that coolant shot out mach 10 and just drenched me and everything else. From that I learned and haven't made a giant mess since, but the ire for draining coolant on this truck remains xd