The Nissan Path

I am look at buying a 2006 2wd pathfinder, the seller bought it in 2007. A year ago he was towing a trailer and the transmission slipped a little, so they parked it and have put 200 miles on it since. The radiator is not factory but the lines are all routed correctly and it doesn’t look like a new transmission has been installed. I checked the transfluid and it’s brown brown but no coolant in it. I drove it 50 miles for it up to temp got on the interstate and no slippage, I wonder if it has made it this long would a drain (or flush) and fill with filter replacement might get a few years out of it.

You if thinks its never had new fluid or its been a long time. l'd replace the fluid.

But at this age (144k miles with towing) I would not do a flush.

A flush of very dirty fluid can push dirt in valvebody tiny crevices. I once ruined a valvebody by flushing a high mile tranny at the dealer.

Do a drain and fill as described n here:
viewtopic.php?t=19117

Thank you for the reply. I don’t think i worded the question very well. I was looking to buy the 06. If it’s made it to 144k miles no signs of the radiator fail and the trans fluid is brown so they didn’t drain the mixed coolant and transfluid and add new. I think they felt some slippage while towing because it’s so old and dirty. I can buy it pretty cheaply.

If there has been signs of slipping and a new radiator installed, plus the fluid appears brown (on the dipstick, I'm assuming?)...then I would pass on it. For starters, these transmissions don't have filters, but screens, which usually don't get serviced unless it's being overhauled. If there is enough debris in the fluid to restrict the flow, then the trans needs to be rebuilt, not serviced. The factory fluid looks brown when drained, but will look a very pale, pink color on the dipstick when checked; some people have even described it as clear or amber. When aftermarket fluid is used for servicing, it will usually look the typical red color on the dipstick. It's possible that the radiator cooler did fail in the past and even if they flushed it out, it is very hard to get out from between the TCM and valve body without removing the assembly and taking the TCM off the valve body to clean under it. If left, it can cause shifting issues which may lead to slipping or shifting issues. There are a lot of R51 Pathys on the market, so I would look around at other options. At the very least, get a CARFAX report on it and have an independent shop or dealer check the the vehicle over and let them know of your concerns. Good luck!

With her buying it in 2007 and the radiator was replaced then and the fluid is dirty now makes me think they caught it before the ATF got contaminated. I drove it for 50 miles and felt nothing. I kinda know what to feel for after just replacing the trans on my 05. I think what he felt while pulling a big trailer could have been caused by the dirty fluid.