Truck suddenly running rough. Plugs replaced. Took in for relearn idle. Told me also 3 of 4 cats clogged and coolant in the transmission. Knew nothing of this issue with these trucks until I looked online to try and figure what was happening with my truck. I am so angry right now. There should be a recall as it truly is a safety hazard. To imagine the thought of driving on the freeway and have your trannie lock up..." hello! this has caught me unaware and I didn't know about this until now and at 127K miles, I am sol on any kind of refund, repair, or anything? they should be liable as I should not be in this position with no recourse for a known safety issue that is now going to cost me more money that I can afford. This is their issue and they should fix it, not me. They knew and they should fix. Regardless, who knows how much actual damage this has caused my engine now" I am so angry right now.... don't know what I am going to do now. But if I buy another truck, I don't think it will be a Nissan...too many cover ups...no responses or fixes...

- Mira Loma, CA, USA

I went to drive the truck and started to notice the transmission slipping. I called Nissan and the service department said there was not a recall for my truck. I have since found out the transmission is no longer usable and that many other people are noticing the same problems.

- Lincoln, NH, USA

I recently purchased a 2007 Nissan Frontier and have only had it since Feb 2014 and all of a sudden there is a strong vibration at 40 mph in the rear end. So I had the tires balanced then re balanced thinking it was the tires. Even went as far as replacing the rear tires. After that did not correct the issue I then took it to a Nissan dealership and they determined that it was a failure in the radiator that leaked coolant into the transmission. They told me that my radiator and transmission need to be replaced. If I have it done before my truck reaches 100K it will only cost me 3000 to get it fixed and Nissan will pick up some of the cost. But if I go over 100K I will be responsible for the full repair cost. My current mileage is 98910. I had purchased an extended warranty through the place I had purchased the truck and because they don't cover the radiator I am now liable for the repairs. So now I am at a loss, just started paying on the vehicle and now I have to spend 3000 at min to get it fixed. I should not be putting this kind of money into this truck after owning it for less than 6 months.

- Danielson, CT, USA

Coolant backed up into transmission and destroyed the transmission and radiator.

- Desoto, TX, USA

I took my truck into the dealership for a diagnostic test. I was told that I need a new timing chain. Nissan has been aware that the timing chain systems installed in the subject Nissan vehicles are prone to premature failure, and Nissan continued to install defective timing chain systems in the subject Nissan vehicles knowing that they were prone to premature failure. Nissan not only refused to disclose the problem, but also actively concealed knowledge of it. Nissan undertook affirmative efforts to conceal the failures through, among other things, technical service bulletins issued to repair facilities. Although Nissan was aware enough of the problem to issue multiple technical service bulletins to repair facilities, informing them of the need for timing chain systems to be replaced, Nissan selectively chose not to inform consumers of this fact. Nissan concealed this so that the warranty period on the subject Nissan vehicles would expire before owners become aware of the problem. Through this practice, Nissan unlawfully transfers the cost of replacement from itself to the owners of the subject Nissan. The fact that the timing chain systems were prone to sudden premature failure is material to consumers because it presents a serious safety issue and places the driver and passengers at a risk of harm.

- Douglasville, GA, USA

I have a 2007 Nissan Frontier which has only a 122,431 miles on it and something went wrong with the transmission. When I was going up the hill it was like it just stalled out on me. I've been doing research on it and it seems like alot of other people is having the same problem and it seems like Nissan is just trying to hide the problem. If its something that their at fault with they should be the one who fixes it. I depend on my truck everyday to get me to work and if its the coolant and transmission fluid is mixing its a very expensive fix which I can't afford and the other people shouldn't be reliable for so I wish U would consider this and do and investigation on it and try and get this problem fixed before it messes anybody else's up and puts them out alot of money. There's just to many people on the internet with the same problem and if U all don't do something about it Nissan is just going to keep doing the same thing til someone does something about it. Thank you for your time

- Mount Vernon, KY, USA

Transmission started to rumble when shifting to overdrive. Looked into the issue and heard about the cross contamination issue. Looked for symptoms and found that water had gotten into the transmission and flud in my radiator. I have spend hundreds on flushing them out and bypassing the radiator. Transmission is still rumbling. The extended warranty does me no good, for I am over the covered milage limit. [xxx] 'parts of this document have been redacted to protect personally identifiable information pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).'

- Alvin, TX, USA

The automatic transmission started shifting "hard" and the heater stopped working. I took it to a local shop and they told me that the radiator fluid had contaminated the transmission fluid, and visa versa. I needed to have a transmission shop look at it. They told me the same thing as the previous shop, but also that I would be needing a new transmission and radiator system, at the cost of $4848. This was due to a failed transmission fluid cooler located in the radiator assembly that allowed coolant to mix with and contaminate the automatic transmission fluid, resulting in damaged internal transmission components and a damaged internal transmission computer. After researching, this has occurred to hundreds of Nissan vehicles, including 2005-2010 Nissan pathfinder, Frontier and xterra vehicles. Nissan has been aware of this problem since 2007 and has undertaken no preventive measures to protect consumers from failure.

- Missoula, MT, USA

The transmission had been shuttering and slipping for a couple of months. It was getting worse so I took it to kings transmission on 3-13-14 to have it looked at. They discovered water in the fluid and informed me that this model of vehicle had a wide spread problem with the radiator failing and leaking coolant into the transmission cooling lines. The truck is now at a Nissan dealer getting a new transmission and radiator.

- Brier, WA, USA

No power to wheels...transmission coolant and engine coolant mix together due to malfunction in radiator causing catastrophic transmission failure. Cost to replace radiator and transmission is $5200...research on this matter indicates that Nissan Corp. Knew of the problem and that a class action law suit coving this defect has been approved, but, the deadline to apply has passed...my truck just broke and it is now too late to register for the approved class action law suit. How can I get reimbursed like so many others have"?"

- Thousand Oaks, CA, USA

Truck begin shuttering and shifting hard. Took it to Nissan and they said the coolant had mixed with the transmission fluid and I will need new transmission and radiator. Cost about $5500. Nissan service told me the first time everything was okay. Only after I took it in the second time after I had 100,000 miles then they told me about the leak. Nissan refused to pay for any of this.

- Cleburne, TX, USA

I purchased this truck from a used car auto dealer with 137,477 miles on it. Their warranty was up before I was aware I had a serious problem that got progressively worse. While driving locally and on the highway at speeds between 35 and 65 mph the truck started to shake and vibrate intermittently which caused an erratic control of the truck. After approaching several auto repair shops about the issue no one seamed to have a solution except one. They told me that a class action suit was issued against Nissan about a defective transmission and radiator combination cooler cross contaminate problem that destroys the transmission lubricate and electrical shifting functions of the transmission. It cost me $3,728.95 to fix the problem and I would like to get my money back from Nissan if possible. All post about the class action suit puts me outside on the initial settlement. Thank you

- Scotch Plains, NJ, USA

Nissan Frontier 2007 - transmission started acting funny making a rumbling sound. Took it in for service and found that the radiator had leaked into the transmission. Yes, common problem it would seem. Bit the biggest problem is that to get it back on the road safely is going to cost thousands of dollars! and Nissan knew, has known and knows about this problem but has done nothing to fix it!!! they should be held accountable for a problem that is so wide spread!

- Pembroke, VA, USA

An internal crack on the oil cooler tube caused internal leakage of engine coolant into the transmission causing transmission failure.

- Aptos, CA, USA

I was returning home from townshend, a distance of approximately 35 miles through the back roads of Vermont. These roads are very rural over dirt roads covered in ice and light snow. The transmission started to buck and the wheels started to 'chatter.' My wife had borrowed the truck to make a run to the dump earlier in the week and mentioned the chatter in the wheels and that the truck should be taken to the garage. However, I was unable to get a repeat of the problem until Friday. The chattering made the truck slip on the road and veer close the drop off above the creek along augur hole road. I pulled over to the far side of the road away from the drop off until the engine cooled down. It was 7 degrees out at the time!! the nearest help would be a couple of houses a mile or so away! there was no warnings from any of the systems! not even a check engine light! it took about an hour and a half to cool down and I was able to limp the car home. I intend to notify our senators and congressman of the issue at play here in Vermont. This is an issue that could have been prevented by a simple recall!!! what are you waiting for" how many cars and trucks are affected by this design/engineering flaw in these systems?"

- Brattleboro, VT, USA

My 2007 Nissan Frontier developed shuddering in the transmission. It has received all regular service at 3,000 mile intervals. Today I was told that the transmission is contaminated with radiator coolant due to failure of the radiator and will cost $6200 I note innumerable examples of radiator failures with catastrophic transmission failure in the public forums and Nissan agreed to a class-action settlement up to 100,000 miles with a $2500 deductible. Most vehicles are over 100,000 miles. This is a known defect which should be subject to a vehicle recall.

- Raynham, MA, USA

I had been noticing my automatic truck shutter before thumping into gear months before I actually took the truck into the Nissan dealers shop for analysis. When they inspected, I was told my transmission had been damage due to contamination by engine coolant and I would need a new transmission. The source of the contamination is a cracked atf line that runs through an engine coolant chamber in the radiator. This defective part and design came directly from the Nissan factory. Nissan knew about the defect and failed to notify the consumer or replace the failed transmissions @ no cost. Please advise of any recalls and results from the investigation.

- Douglasville, GA, USA

I was driving my truck when it began to slip at round 45 mph. The shifting then became very hard. I looked on-line and saw websites discussing transmission/radiator problems. I opened my radiator and saw it was very milky in color. Took it in to the dealership and told that I needed a new radiator and transmission because of a known problem.

- Cincinnati, OH, USA

The contact owns 2007 Nissan Frontier. The contact stated that coolant leaked into the transmission erroneously and caused the vehicle to stall. The contact took the vehicle to the dealer where a diagnostic test was performed. The dealer confirmed that radiator fluid was leaking into the transmission. The vehicle was not repaired. The contact called the manufacture regarding the radiator leak and was advised that the vehicle was unsafe to drive. The failure mileage was 120,000. Updated 01/09/14

- Pahoa, HI, USA

Our truck overheated on 10/17/13. The garage informed us the internal radiator had busted and had leaked antifreeze into the transmission and transmission fluid into the radiator. According to the mechanic it had been this way for awhile. There was nothing to indicate there was a problem this major. Nissan could not explain how this could have happened nor why only that if we give them 2500 they will replace the radiator and the transmission. This radiator and transmission are both factory installed. I think this is a definite safety issue as this will cause the engine to overheat and the transmission to go out and leave you stranded. This is a very costly repair that most people cannot undertake. So far we have paid $300 for a "band-aid" fix until we can find a way to resolve this issue. This is a definite problem with the Frontier 4.0L and it's only fair to say there is something wrong with the factory radiators.

- Hiddenite, NC, USA