2nd transmission cooler installed

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disallow
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Postby disallow » Mon Apr 16, 2012 10:56 am

All of the research I've done says that if you keep your transmission temps below 250F you will be fine.

Keeping the temps too low may not be a good thing either.

What are you basing your desire to keep trans temps below 160?

t


Fossilfuleburner
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Postby Fossilfuleburner » Mon Apr 16, 2012 2:59 pm

I try to keep my transmission temperature under 180. Sometimes its unavoidable for it to climb to 200 or even 210 for a short period of time but I would not operate mine up to 250. 250 is the top range of my transmission gauge.

Image

Fossilfuleburner
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Postby Fossilfuleburner » Mon Apr 16, 2012 3:01 pm

I agree that too low is not good either. The fluid will not have the proper viscosity. I've read that 150 should be the ideal minimum operating temperature.

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Postby Fossilfuleburner » Mon Apr 16, 2012 3:10 pm

Disallow, what is the loaded weight of your travel trailer? That unit looks huge! What transmission temperatures do you usually see when towing? I've been looking at 20-21 foot toyhaulers and travel trailers.

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disallow
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Postby disallow » Mon Apr 16, 2012 3:24 pm

Hey there Fossilfule,

The UVW (unladen vehicle weight) on my Keystone Passport 280BH is 4500lbs. I figure loaded its about 5500lbs. The axles max out at 6040lbs.

I haven't installed my temp gauge yet, haven't had time. I also tow on very flat land, so I'm not that concerned.

I don't really agree with your number of 150F. If we left our water/oil cooler hooked up, the lowest we would see would be around 170F, as it wouldn't get any cooler than the water temp of the engine. The real question should be "what temp did Nissan design the tranmission to operate at?". I haven't found that, but all the reading I've done says normal operating should be below 250F, and occasional spikes above thatshould be ok.

t

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fidelcastrol
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Postby fidelcastrol » Wed Jul 18, 2012 8:17 pm

Question about the factory cooler, where does the hot fluid from the transmission come in at?

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smj999smj
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Postby smj999smj » Wed Jul 18, 2012 9:59 pm

A metal line goes from the right side of the trans to the front of the vehicle, attaches to a molded rubber hose that runs around the side of the radiator and AC condensor, to the inlet of the auxilary cooler mounted in front of the AC condensor. Outlet side attaches to a molded, rubber hose, around the side of the AC condensor and radiator, to the radiator cooler tube inlet. From the radiator cooler tube outlet, a molded, rubber hose connects it to a metal line which, on the right side of the vehicle, runs back to the side of the transmission.

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fidelcastrol
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Postby fidelcastrol » Thu Jul 19, 2012 5:30 am

Ok when looking at the factory cooler is the upper passenger side corner of the cooler where the hot oil comes in? Kind of confused by your explaination, just got this truck and learning my way around.

goodmatt78
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Postby goodmatt78 » Tue Nov 27, 2012 2:48 pm

Any temp readings with 2 external coolers vs OEM set-up vs bypass only?

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smj999smj
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Postby smj999smj » Tue Nov 27, 2012 9:41 pm

I thought this link might be of interest to some:

http://www.digi-panel.com/trannyoil.htm

goodmatt78
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Postby goodmatt78 » Wed Nov 28, 2012 6:17 am

Thanks. I have a 08 V8 and 81K miles. I am looking to bypass and add 2nd auxiliary behind the factory external cooler, but I am worried about running too cool in winter conditions and normal driving.

I plan to hook a scanner up tonight and see what temps I currently run at and how long it takes to come up to temp. Then temporarily bypass and do the same.

Then I will at least have some numbers to decide on 2nd external or aftermarket radiator replacement.

Thanks.

Calicajun
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Postby Calicajun » Wed Nov 28, 2012 7:20 am

Hi,
After you added the second trans cooler, both which are in front of the radiator has the engine temperature increased? Looks like with the two trans coolers mounted in front of the radiator it would cause less air flow to the radiator.

goodmatt78
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Postby goodmatt78 » Wed Nov 28, 2012 8:53 am

I am re-thinking the 2 external coolers after reading this thread:

http://www.thenewx.org/forum/showthread.php?t=30287

In summary, the Radiator/trans cooler is way more efficient than an external...especially at low speeds.

I will be researching a good aftermarket radiator to swap. I think they can be had for <$200.

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hfrez
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Tranni Temp ranges that are safe.

Postby hfrez » Thu Jun 05, 2014 4:59 pm

Well, I see these posts are a few years old but I'm going to put in my 2 cents anyway.

I have the Bully Dog GT installed and it allows for various readings off of the ECU and one of which is the Transmission Temp. I set an alarm on the GT that will beep if it ever reaches or goes over 150F. I have hardly ever heard it go off. Granted I'm not towing anything yet but the only time I ever hit that mark was during repeated, consecutive, hard acceleration. To me it seems that normal operating temperature is very close to that since I see it sway between 135 and 145 under normal driving.

I was looking for a thread like this because I'm going to start towing around #5000 to #5500 trailer and wanted to know what to expect on the transmission temperature. It seems that (if 250F is the top end) 180F to 200F during towing is probably what to expect and just fine. I would say that someone towing on a regular basis would probably have to make adjustments to the maintenance of the transmission fluid on a more frequent schedule.

My F150 was equipped with a towing package that included a larger transmission cooler but then again the truck was able to tow over #8000. I'm not sure what the temps were on that but I never had an issue with it towing a #5900 travel trailer for 7 years.


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