MayorMcCheese

With summer approaching and my long list of new performance mods I want to ensure my transmission stays cool and i know our RL has a transmission cooler somewhere on the radiator ..

does anyone one know the size of it? I'd like to replace it with a new cooler due to mine being OEM and 10+ years old I would like peace of mind knowing I have a new cooler doing its job prolonging my transmission

I know we share the same engine as a Type S TL but do we share a similar transmission?

BSQ

The RL does have an external transmission cooler (see diagram). The part number is 25510-RJA-003. The RL doesn't share the same transmission with the TL Type-S.

kcjohnnyboy

Sorry to bump an old thread but I just learned about a friend that had an issue on his RL. My friend's 05 RL, in the past year, had his radiator blow out and the coolant mixed in with the transmission fluid. Thus, coolant entered his transmission! So, I'm worried that this can happen to myself and other RL owners. Has anyone done a replacement of the OEM cooler to an external transmission cooler? If so, does someone have the how to and what they did?

RL09

Scaring the bejeesus man. my miles are high now gotta watch out.

You mentioned your friend's car, well, what happened to it? What was the solution? drain and fill oil or new tranny?

How did he know it blew? any lights, warning lights? or just saw oil niagaring out?

truonghthe

its happend in cars that don't get taken care like it should be, so what happen is the transmission line run through the radiator (know as heat exchanger) over time people do not replace the coolants cause the heat exchanger to be corroded and eventually burst inside the radiator causing coolant mix with ATF.

If not caught in time and the driver keep driving you will need a new transmission as well (doesn't take much about 10-15 miles). This happen to alot on TL and MDX.

RL09

Thanks. Certainly worth watching out for.

Its listed under maintenance minder 5. What mileage interval is that any idea?

truonghthe

If I am not mistaken its the sub code "5" for coolant replacement. But if you don't drive the car often I would do it every 3 years.

RL09

Well then i'm certainly due. I suppose if it comes down nice and clean, we're good. If it comes down brown, order a tranny rad. lol

truonghthe

Yup, on all of my car the coolant actually clear blue.

RL09

Next week!

HDNBenjamin

Like Truong has suggested above..replace ypur coolant. it is such an easy job with the spill proof coolant funnel kit. absolutely easy like changing the oil.

kcjohnnyboy

My friend has then sold the car but it's just what I was told from him when I last saw him, and I haven't seen him in over a year. All my friend told me was that his radiator busted and coolant got into his transmission. He said he had to drain and flush the transmission fluid 3-6 times to try to get all the coolant out. He said he didn't think he got it all out and that his transmission didn't shift the same after the incident. He just gave me a fair warning to try to do an external oil cooler, away from the radiator, to avoid my car to experience what he did in his RL. He told me nothing else to look out for when his blew out.

kcjohnnyboy

So, has anyone rerouted the transmission line that goes through the radiator to bypass it to another cooling option, like a separate transmission cooler? Do you know what I mean?

kcjohnnyboy

I also found out this issue seems to be more of a problem with the MDX, so just a heads up. I'll be searching there for more info. Thanks!