AFAIK, this problem only affects US Frontiers/Pathfinders/Xterras, 05-08 (09?) with the 4.0 and AT.
I had this problem in my 06 Frontier. Around 90k, I began to notice a slight shudder going in/out of OD. Kinda felt like driving over a rumble strip. I pulled my tranny dipstick, and it looked like pepto. Pink and milky, instead of pink and clear. Not good.
Because of my mileage, and the extent of contamination, I decided to replace my radiator and cooling system altogether. I put in a new radiator (
www.radiatorbarn.com, great prices, good service), thermostat, and I looked at the pump but its good. Also did the bypass at this time.
Frontiers with the tow package, or with the Nismo Off-road from factory will have external coolers. This external cooler is enough for cooling the trans as long as you don't pull exceedingly heavy loads up mountains frequently. This bypass can be done for basically free, just remove the top line (out) from the trans where it connects to the radiator, then loop it back to the bottom line's spot (in) on the trans, effectively looping the hose, bypassing the radiator. Just remove the unneccesary other line, and cap the holes if you choose.
The clutches in the torque converter do not get along well with any water content in the fluid, causing the shudder.
Going to Nissan first, they say trans needs to be replaced, at the tune of $4500 :smileeek:
Went to a trans shop, say it could be rebuilt for $3800.
However, I didn't think it was that bad yet, so I did a series of three flushes (not just drain and fill. the trans shop did it with the pump thing), driving about 150 miles in between each flush. The first one, we pumoed about 20 qts through there, and as each went on, the shudder got better and better. With the third and final flush, I put in Amsoil ATF and **** improver, and now its perfect!:victory:
Total expenses: about 650, including radiator, flushes, and all fluids. Much, Much better than 4500!
Disclaimer: YMMV
Warranty note: There are a bunch of foks feeling all entitled on other forums and demanding legal action, etc due to this problem. However, it is not Nissan's fault, nor their problem to fix. They could not have known that their radiators (sourced anyways) would fail internally after 50-90k miles. They will not honor the trans under warranty, as it was caused by an uncovered part, the radiator. (which is of course, a maintenance item, not intended to last the life of the vehicle anyways.)
Let me know if anybody has any questions.
