Transmissions are precision machinery that do not like contamination in their fluid. Even a small amount of contamination will cause issues. SureTrack community member Nhaugen had a 2005 Nissan Pathfinder in the shop where the transmission would chatter at highway speeds. They posed the question to the community, and with the help of fellow community member trannyman1 and others, they were able to resolve the issue quickly.
The following Community Fix summarizes the interaction between members of the community that led to the solution.
Vehicle
2005 Nissan Pathfinder SE 4.0L
Title
Vehicle chatter at 80km/h on highway, replaced transmission and cooler.
Complaint
Vehicle feels like it goes over rumble strips at around 80km/hr at steady throttle.
Diagnostic Steps Performed/Parts Replaced
Transmission fluid was changed recently and customer had a loud electrical whine from TCM. Checked fluid level and it is good,
I suspect transmission issue, Just wondering if anyone can point me in a direction as to any PIDs a guy can monitor to find maybe torque converter clutch slippage or internal transmission slippage, I will also manually check line pressure. just trying to find the least intrusive way to diagnose this thing,
Best Answer from Community Member trannyman1
Most of these I see have had the transmission cooler inside the radiator rupture and ruin the transmission. Even if you flush them, you normally can’t get them to quit shuddering. Check the fluid really good with either test strips for glycol contamination or the quick and dirty way. Get a metal spoon and put some fluid in it. get a lighter and heat it up. If it has much glycol, it will boil before the fluid will get hot enough to ignite. Regardless, most of these I get with a shudder have had glycol contamination. On a side note, if the radiator has ruptured, I’d recommend a remanufactured transmission because it normally ruins the TCM as well as the rubber seals.
Cause
Transmission fluid contaminated with coolant.
Correction
Installed remanufactured transmission and new transmission cooler. Problem solved.
SureTrack® is a powerful value-added feature available with select Snap-on diagnostics tools. It offers an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community.
Want more? Click here for more information on using SureTrack.
Looking for diagnostic tools? Click here to request more information on Snap-on diagnostic tools.
New or Expired SureTrack users: Click here for authorization key instructions.
