WheelinintheR50 Posted February 21, 2012 Share Posted February 21, 2012 I just recently put a new transmission in my truck and i want to bypass the whole factory setup.. I live in VT and its pretty cold here in the winter and i was wondering if id be running my transmission too cold. i bought the cooler from AC 4X4. Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 How big of a cooler did you get? What is it rated for? Link to comment Share on other sites More sharing options...
WheelinintheR50 Posted February 22, 2012 Author Share Posted February 22, 2012 it is a 12,000 gvw transmission cooler. Link to comment Share on other sites More sharing options...
Towncivilian Posted February 22, 2012 Share Posted February 22, 2012 Why do you want to bypass the cooler in the radiator? You'll be fine with just the auxiliary cooler, the transmission will still get hot enough. Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 yeah, a 12k cooler will be perfect, as long as you don't plan on towing anything too heavy. The Pathfinder's vehicle weight should only run the cooler at half "capacity" Link to comment Share on other sites More sharing options...
WheelinintheR50 Posted February 22, 2012 Author Share Posted February 22, 2012 (edited) my truck sees alot of stop and go traffic combined with lots of hard offroading and i hear the factory coolers clog up.. so should i bypass the stock cooler all together and just go through the aux cooler. Edited February 22, 2012 by WheelinintheR50 Link to comment Share on other sites More sharing options...
Towncivilian Posted February 22, 2012 Share Posted February 22, 2012 The factory coolers clog up in WD21s; I've read of one, maybe two cases of the stock cooler clogging on an R50. If you maintain the fluid, it won't clog up on any vehicle. I would run the aux cooler in-line with the stock cooler in order to get the fluid up to temperature quicker. Install a 3/8" Magnefine in-line filter too. Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 R50's have the same problem as the WD21... WD21's have just been around longer so more cases have been brought to light. Only a matter of time before the VG R50's are dirt cheap on craigslist because of no reverse. Link to comment Share on other sites More sharing options...
Towncivilian Posted February 22, 2012 Share Posted February 22, 2012 (edited) What specifically about the tube cooler used on Pathfinder RE4R01As lends itself to clogging? It's just a friggin tube. By this logic, doesn't every vehicle with a radiator tranny cooler have the potential to clog? How much crap does a trans need to shed to clog up the cooler? Edited February 22, 2012 by Towncivilian Link to comment Share on other sites More sharing options...
Kyle94 Posted February 22, 2012 Share Posted February 22, 2012 (edited) R50's have the same problem as the WD21... WD21's have just been around longer so more cases have been brought to light. Only a matter of time before the VG R50's are dirt cheap on craigslist because of no reverse. matter of time? heck ive seen two on there in the last month with no reverse... i too have avoid the stock cooler and added a 28gvwr(?) cooler or a 24... i honestly don't remember... lol. some may say over kill, so to them Edited February 22, 2012 by Kyle94 Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 The cooler doesn't clog, the fluid gets old and can't be held at required pressure and the clutches start slipping. And because reverse requires 1.5x+ the pressure of the forward gears, it's usually the first to go. Link to comment Share on other sites More sharing options...
Towncivilian Posted February 22, 2012 Share Posted February 22, 2012 So what perpetuates the myth of requiring to bypass the stock cooler? Why not just exchange all of the fluid via the cooler return line, slap a Magnefine on it and maintain the fluid/filter from then on? Sure, an auxiliary trans cooler is still a good and relatively cheap addition, but aren't we spreading incorrect information by claiming the cooler clogs and deprives the trans of fluid? Link to comment Share on other sites More sharing options...
Tungsten Posted February 22, 2012 Share Posted February 22, 2012 I agree with that, never bypass the stock cooler. Just put a magnefine and all your clogged cooler issues are gone. If you run the fluid too cold in the winter, you will kill the transmission. Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 So what perpetuates the myth of requiring to bypass the stock cooler? Why not just exchange all of the fluid via the cooler return line, slap a Magnefine on it and maintain the fluid/filter from then on? Sure, an auxiliary trans cooler is still a good and relatively cheap addition, but aren't we spreading incorrect information by claiming the cooler clogs and deprives the trans of fluid? I'm not really sure how or when it started, but I can assure you that I had to replace the transmission on both of my trucks, and I "cleaned" out the stock cooler in both radiators, and nothing was blocking the flow of the carb cleaner I was using. It sprayed in one side, and very quickly came out the other end, slightly reddish. Doing a fluid exchange and adding a magnefine is probably good enough, but usually people come asking for help when it's already too late, and their truck can no longer reverse under its own power. Personally, I would do a fluid exchange and put an external cooler on any automatic pathfinder that was in my ownership, wd21 or r50, just for the ease of mind that an external cooler will keep transmission temps down, especially if towing or hauling heavy loads. Link to comment Share on other sites More sharing options...
JamesRich Posted February 22, 2012 Share Posted February 22, 2012 I don't think bypassing the cooler is a good idea either especially for the guys up north. Just think how flexible those rubber lip seals on the clutch pistons will be at 10* to 15*. The best setup when adding a external cooler is to put the auxiliary cooler getting the oil first then to the cooler in the radiator. This way if the external cooler removes too much heat the radiator will warm it back up. If your worried about clogging just change your oil more often. Oil is cheap, I change it every time I change my engine oil on my quest. Most nissans only have a screen filter so it doesn't need to be changed unless your trans is shot already. Just drop the plug while draining your engine oil, then top it off just like the engine. Your not changing all the oil each time but your getting fresh additives each time. My quest is almost to 160k and still shifts fine. My quest is 11 years old and I've had it since it was new. The price of the trans is now the value of the van. I know the VG will run forever but when the trans goes it would cost more than the van is worth to fix it so I'm taking care of it. James Link to comment Share on other sites More sharing options...
silverton Posted February 22, 2012 Share Posted February 22, 2012 The best setup when adding a external cooler is to put the auxiliary cooler getting the oil first then to the cooler in the radiator. James This basically negates any benefit of having an external cooler. Also, by bypassing the stock cooler, if you ever over heat your engine, you won't cook the transmission fluid. Another thing that people fail to make a connection to, the temperature of the engine coolant, is the temperature of the transmission fluid. Link to comment Share on other sites More sharing options...
WheelinintheR50 Posted February 22, 2012 Author Share Posted February 22, 2012 It was already "too late" when i didnt have reverse last fall. so thats why i want to bypass it all.. because i did a transmission swap in my driveway. in the winter in like 25 degree snowstorms.. it sucked but im glad to have my truck back. Link to comment Share on other sites More sharing options...
adamzan Posted February 22, 2012 Share Posted February 22, 2012 As someone who lives where it gets pretty damn cold (-30C), this is the second winter I've had my rad cooler bypassed, and the tranny still warms up just fine. My transmission was not exactly in the best shape when I bought the truck (didn't find out until later), but changing the fluid regularly like jamesrich does, has helped string it along. The only thing I notice in the winter is that if I don't let the truck run for at least 5 minute when it's this cold, that the tranny will slam hard when putting it into drive or reverse. Like dennis, when I went to clean my stock cooler, it flowed fine as well... Link to comment Share on other sites More sharing options...
Tungsten Posted February 23, 2012 Share Posted February 23, 2012 I would say as a safe bet, if you think you have a clogged stock cooler then bypass it. I didn't do a bypass because I put a new radiator in along with my cooler. Link to comment Share on other sites More sharing options...
silverton Posted February 23, 2012 Share Posted February 23, 2012 if I don't let the truck run for at least 5 minute when it's this cold, that the tranny will slam hard when putting it into drive or reverse. Like dennis, when I went to clean my stock cooler, it flowed fine as well... When my trans is cold, it slams the gears too. I like it and wish it were always like that! Link to comment Share on other sites More sharing options...
Tungsten Posted February 23, 2012 Share Posted February 23, 2012 Honda Passports/Isuzu Rodeos will slam through every gear hot or cold and average people don't like that. Link to comment Share on other sites More sharing options...
WOT Posted February 23, 2012 Share Posted February 23, 2012 I thought the tranny fluid was somehow hotter than the coolant, through friction in the tranny I thought, and the coolant just aided in keeping it cool. Does the tranny like/hate certain temps? Link to comment Share on other sites More sharing options...
Towncivilian Posted February 23, 2012 Share Posted February 23, 2012 Anything over 220F for long periods of times will quickly oxidize the fluid and start degrading the clutch packs. Anything less than 120F is probably not ideal for the trans, and it also doesn't allow any potential moisture build up to eventually boil off. Link to comment Share on other sites More sharing options...
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