The Nissan Path

Hey all,

I have done quiet a bit of reading on the transmission issues with our pathfinders. I had shudders at 40mph and beyond, once I started reading I was convinced that i had coolant in my transmission. I stuck a metal extension into the coolant reservoir and nothing fishy. I have sent the transmission oil out for analysis, still waiting to hear back. In the meantime i went and did the radiator bypass mod. Something interesting i began to think of.....

My radiator had coolant in it, when i took off the transmission lines to bypass the radiator I just had a slow drip of what appeared to be transmission fluid. Now hear me out.. IF the radiator had in fact ruptured shouldn't I have been getting a steady stream of fluid coming out? I mean anything more than a slow drip right?

it would depend on the extent of the leakage (rupture), and whether or not the radiator cap was on or not
with the cap on (system sealed), it would reduce the flow draining
was the trans fluid "milky" or "milk shake" in appearance?
if not, you're probably fine

eieio wrote:it would depend on the extent of the leakage (rupture), and whether or not the radiator cap was on or not
with the cap on (system sealed), it would reduce the flow draining
was the trans fluid "milky" or "milk shake" in appearance?
if not, you're probably fine

Nope not at all, matter of fact had a transmission flush last year.. first one at 140k miles (late I know) but the shop didnt make any mention of the fluid being a different color.

So let me ask this, why does the transmission fluid even run through the radiator and then to the cooler infront of the radiator? Why not just straight to the cooler? Am i missing something?

the internal cooler in the radiator does cool the trans fluid, and also helps the trans fluid get up to operating temp by warming it when cold
most cars & trucks rely solely on this system, and have no external cooler
our trucks have the external cooler added to aid cooling, especially under towing loads
both is good, but in most circumstances, not essential
what year is your truck, mileage, owned since new?

eieio wrote:the internal cooler in the radiator does cool the trans fluid, and also helps the trans fluid get up to operating temp by warming it when cold
most cars & trucks rely solely on this system, and have no external cooler
our trucks have the external cooler added to aid cooling, especially under towing loads
both is good, but in most circumstances, not essential
what year is your truck, mileage, owned since new?

2006 164k owned since about 40k

regarding the shudder, maybe it's a vibration?
have you checked your drive shaft u-joints and wheel bearings?

eieio wrote:regarding the shudder, maybe it's a vibration?
have you checked your drive shaft u-joints and wheel bearings?

Next thing to check will be the u joints, I appreciate your quick response. I probably wont have a chance to check the u joints today but probably sometime this week. Ill let you know what i find.

Actually, it passes through the auxiliary cooler before it passes through the radiator's integral cooler, this way it can maintain the trans oil at approx. 175-200 degrees F., which is what the operating range of the transmission oil should be. Without running it through the radiator, the trans fluid usually runs a little cooler, around 150-160 degrees F.

One of the u-joints in my front drive line went bad and created the same shudder. It's supposedly a fairly common issue.

stmcelroy wrote:One of the u-joints in my front drive line went bad and created the same shudder. It's supposedly a fairly common issue.

It is. It happened to mine about a year ago.