Hey everyone,

I'm looking for advice on car towing tips. I have a 2005 2WD Pathy with 191k miles, never towed anything with it. It has the Airlift 1000 kit installed and the transmission bypass set up.

I live in Phoenix, AZ we might be moving to Asheville, NC. I have a second car which is a 2005 350z roadster and I was wondering if it would be wise to tow the Z behind the Pathy? Some of the roads leading up to Asheville can be pretty steep with sharp turns and I worry about overheating and possible transmission damage.

Any advice on how to prep Pathy for this long haul trip? I'm also open to other options, like towing the Z behind a U-Haul and following if that is a safer option.

Thank you for the help

If you are towing in the summer I think the bypass is not a great solution.
Yes the bypass works and for years...
But the heat exchanger that got bypassed in the transmission does lower temps..

These weight involved otherwise dont sound too bad.. but I strongly urge you to install a new radiator to re-establish the original factory plumbing.

The are great and strong transmissions but bypassed, summertime towing in the southern US is a recipe for disaster.

Most model years also had an addtional external tranny cooler but the original design is for both to be present.

I used to own an 05 Xterra (same engine same tranny) and replaced the rad first thing I got the Truck even though I dont tow.
Its not cheap but its TONS cheaper than replacing a transmission.

PS: Would the Z be on a trailer? Or rolling on its tires? Is it auto or manual?
The auto tranny BTW is the same as in your Pathfinder.
Keep in mind automatic transmission cars will get their trannys destroyed by being towed by any distance with driving wheels on the ground even if in neutral.. even some manual transmission are not ok with it.. .. I am uncertain if the manual on the Z falls into that category but the auto does for sure.

Thank you for the fast response

I was thinking about renting an auto transport trailer through U-Haul for the Z: https://www.uhaul.com/Trailers/Auto-Tra ... Rental/AT/

After seeing what you said, I am definitely going that route to avoid transmission damage since it is an automatic transmission.


I think I will go with the route of getting a new radiator replaced. I had a prior incident where the bypass hose popped off while I was in downtown LA for vacation. I was stuck on the 110 freeway during rush hour traffic. That was not a fun experience lol!

Just got a quote from YourMechanic and they quoted me $651.57. Would you have any advice on which radiator brand or ID code to look for? I'm afraid they might try to replace it with the faulty OEM radiator.

650 is not a low price.. but then the amount of labor to change a rad, is not trivial for these trucks and the radiators are not cheap either so it may be perfectly reasonable ..... I am simply not sure since its been too many years since i dealt with this.

But I applaud you to replace the radiator its the best practice solution.

As for the OEM radiators they are all good now.

As for the best money/quality balanced radiators other than OEM suggestions,... I will leave that up to those of us who have done this more recently than I (and there are 1 or 2 folks on here that I am sure will chime in within a day or two)

$650 is a lot of money! You can get a Spectra Premium radiator from Rockauto.com for around $120 I think? It's been a popular, aftermarket choice over the last few years. It'll take 2-gallons of coolant (2005 used the green Nissan coolant, but you can use the one color fits all type if you want, like Prestone). Book labor time is 2-hours. Auto transport is the way to go. If you don't have a 7-pin tow connector and an electronic brake controller, check with U-haul because you may need it with the auto transport.

PathAZ wrote: ↑

Wed Jul 08, 2020 12:11 pm

Thank you for the fast response

I was thinking about renting an auto transport trailer through U-Haul for the Z: https://www.uhaul.com/Trailers/Auto-Tra ... Rental/AT/
.

I used one of those Uhaul car haulers with my Pathy a few weeks ago when I bought a 1977 Datsun truck . We were only going about 90km (55 miles) but it was not pleasant. The trailer vibrated the whole way. When I returned it I looked at the tires, three were bad and one was dead bald! Please check the tires before you take their trailer. Oh and FYI it needed a 4 pin connector, no trailer brakes. I had to borrow a 7 to 4 pin adapter to hook it up.

Spatula wrote: ↑

Thu Jul 09, 2020 4:42 pm

I used one of those Uhaul car haulers with my Pathy a few weeks ago when I bought a 1977 Datsun truck . We were only going about 90km (55 miles) but it was not pleasant. The trailer vibrated the whole way. When I returned it I looked at the tires, three were bad and one was dead bald! Please check the tires before you take their trailer. Oh and FYI it needed a 4 pin connector, no trailer brakes. I had to borrow a 7 to 4 pin adapter to hook it up.

You bought a 1977 Datsun truck? Tell us more...my first vehicle was a 1986 (not a 1986.5), last model year 1986 Nissan truck. Metallic blue just like my Pathfinder, because obviously I had to have the same thing if I could get it! But that one had zero options except an AM/FM radio, big swing-out mirrors, and a chrome rear bumper (aka the "California Package").

U-Haul's equipment service is terrible! I worked at a shop they did U-Haul on the side about 15-years ago. They don't fix anything until it breaks down, basically!

Thank you for the radiator tips everyone. I have my shopping cart ready at Rockauto, lol.

Looking at the back of the Pathy I do see a rubber cap that covers 4 pins on the left side of the hitch area. I'm going to call Nissan to see what price they will give me for the 7 pin adapter. I have a feeling I will be going through Ebay or Amazon for this purchase. Also, any good recommendations on an electronic brake controller?

Since I'm getting Pathy ready to tow I might as well get it ready to tow a lot more since I'm thinking about getting an auto detailing trailer for my business.

I went with the Tekonsha Prodigy P2 Proportional brake control P/N 90885C with Tekonsha brake control harness 3050-P. It's a really nice unit that will make your controller "plug-n-play" to your Pathfinder's controller plug on the right side of your steering column. I did a "how to" thread on my install a few months ago. Since you have the 4-pin connector, you'll likely have the blue trailer relays in the relay box under the hood. To add the 7-pin harness, you'll need to get Nissan relay P/N 25230-7996A. The 7-pin trailer kit is Nissan P/N 99928-XR010 and is really easy to install! It's "plug-n-play" as well and comes with the bracket for your factory hitch to mount the plug; it even comes with the bolts. Here's a link to an article on the installation:

https://x.nissanhelp.com/forums/diy-pro ... inder.html

PathAZ wrote: ↑

Fri Jul 10, 2020 11:28 am

Thank you for the radiator tips everyone.

TheNissanPath to the rescue

Hi. I just wanted to give my experience with that exact drive. My 2005 Pathfinder and 370Z Roadster were both in Scottsdale, AZ. I have made the drive from AZ to Raleigh, NC twice now. Both times I had to drive through Asheville. I drove my Pathfinder and Z on two separate trips. It’s a beautiful drive. I’m glad I didn’t tow anything in my Pathfinder. The Z was a blast to drive throughout the curves and I’m sure you would enjoy it as well in your 350Z.

You have a 2005 Pathfinder with 191K miles, what kind of history do you have with it? Just from what I've read about the pre 2011 trucks I think you're wise to change the radiator if it's the original. If you haven't had it for all of it's 15 years I think it may be worth finding out. It could have been replaced and still have the bypass done. A lot of folks think that's the way to go in general.

I'm not a fan of the radiator bypass and here's why. Auto trans temps can approach 300 F before the transmission destructs. Even if it doesn't fail the damage excessive heat will do to the fluid is permanent. Bad trans fluid then becomes a source of inefficiency in the transmission which causes heat. Cooling it down after the fact does not undo the damage. Unless you have a means of reading the fluid temp you're clueless as to what's going on. So if you're going to bypass find a way to monitor the temp.

What I've chosen to do is add a Hayden 677 plate and fin trans cooler in series with the radiator and OEM cooler. So the trans fluid cooling route is - trans out -> radiator -> first cooler -> second cooler -> trans in. I use an OBD bluetooth scanner and monitor my coolant temp, intake air temp, horsepower and torque relative to engine RPM.

An increase in transmission fluid temp will cause a corresponding increase in coolant temp. I monitor torque because a slipping transmission will not generate as much torque. An increase in heat under the hood will cause the intake air temperature to rise. That and/or a decrease in torque will cause a drop in horsepower. So I'm indirectly monitoring my trans temp and efficiency. Another thing you should know is long pulls up grades in a gear which doesn't allow the torque converter to lock up will generate a lot more heat as the torque converter slips.

The cost of the Hayden cooler was $46 on Amazon. I also needed 4 more feet of hose ( total I used is 8 feet). There are other types and sizes available but the plate and fin are among the most efficient I believe. I mounted it on the passenger side ( OEM cooler is on the driver's side on my 2012, yours may be different) about the same distance from the a/c condenser as the OEM to make sure it has room for airflow. Even though it's smaller and thinner than the OEM I know it's more efficient than the OEM because it cools down much quicker than the OEM does after I turn the engine off.

Lastly, have you checked the cost of having the "Z" transported to NC? I love those cars but would have to give up my Miata to have one. Tough choice.

Interesting to read everyone's experience with the Radiator Bypass. I had my trans serviced last year and mentioned to the Trans shop that I had one of those suspect Radiators. When I told them I had bypassed it, the Owner at the shop says, "oh yeah we bypass those models all the time". I was shocked but, thought, ok I guess the Factory Accessory Cooler is enough cooler for the trans. Now you guys are making me think that I need to put the new Rad in and get it hooked back up the other way.

I guess if I ever start towing a Trailer or something like that I will look at putting the new Rad in but, for now it's just putting around and doing daily driving. Not a whole lot of hard strain on the Trans.

pathy-logical wrote: ↑

Sun Jul 26, 2020 11:54 am

An increase in transmission fluid temp will cause a corresponding increase in coolant temp. I monitor torque because a slipping transmission will not generate as much torque. An increase in heat under the hood will cause the intake air temperature to rise. That and/or a decrease in torque will cause a drop in horsepower. So I'm indirectly monitoring my trans temp and efficiency. Another thing you should know is long pulls up grades in a gear which doesn't allow the torque converter to lock up will generate a lot more heat as the torque converter slips.

The intake tract air is only going to get heated a trivial amount...

Neither the ECU nor your app are actually monitoring power or torque. They are calculating it based on RPM and wheel speed, and whatever else the app owner designed in if it's in your phone (which is to say it's probably only RPM and wheel speed). Even in large engines like power turbines we are almost always looking at the output of a calculated map across variables vs. measurements. There are industrial size torque meters that are in use on very large engines, but YMMV. We use other things like intake vacuum vs. expected RPM.

I think I can see MAF data in Nissan DataScan II with CONSULT II data. But to actually notice a meaningful change in MAF vs. expected RPM on the road...dunno.

Anyway, I don't think anyone has reported a transmission failure due to heat? I think the consensus across all the forums has been the air cooler has been sufficient by itself the whole time. Not a lot of failed transmission stories out there once you eliminate coolant contamination.