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Hi everyone.
I have just joined the forum, live in South Africa and am really in need of advice/assistance.
I recently bought a 2003 T30 2,5 auto realising it needed some work. That thought was an understatement. Car cost around USD3,000 and have spent USD5,200 on repairs already, excluding tyres.
I have replaced timing chain, had a major service, replaced inner and outer cv's, stabiliser links, had transmission overhauled, new fuel pump and alternator, new engine mounts, new throttle position sensor and have had 4 auto electricians try solve a non start issue with car standing for 2 months. Very expensive exercise.
1. Non start eventually fixed - After replacing cam and crank sensors 3 times with OEM from Nissan, car would only start after cranking 30 plus times and many backfires. Read on a forum that loosening the cam sensor and rotating to the 2 o'clock position lets the car start. Sure enough, it worked. Once started I rotate back to its normal position and tighten bolt. The car would start numerous times during the day but next morning same issue, had to rotate cam sensor again. I have now taken the car to a different mechanic who seems to have sorted the issue out. Appears the sensor did not penetrate deep enough by about 1mm. He sanded the exterior sensor housing down by about 0,8mm and problem gone, starts first time every time. Fuel pre-ignition smell also gone.
2. Vibration problem - at around 120km/h, the steering wheel starts to shudder. This can last from 3 minutes to 10 minutes then suddenly goes away and the ride is smooth and enjoyable. Have done alignment and balancing at 4 different places within a week. Does not solve the issue. Tyres are brand new Cargo Marathons. As mentioned above, have done work on suspension and cv's. Rims are not buckled and tyres do not appear to be out of round. Have had steering checked, all good, wheel bearings all good.
3. Transmission - Spent around USD1,100 to have the transmission overhauled.
(a) Car shudders when shifting from neutral to drive. When I need to stop I shift back to neutral to not feel the shudder. Engine and transmission mounts are new OEM.
(b) Car shudders when accelerating from about 60km/h to 80km/h and then disappears.
(c) Driving for first 100km or so, a slight touch on the accelerator causes a shift down without any power, seems to lag and hang until I release accelerator or depress deeper to force actual changeover. Stopping the car for 10min or so and then driving seems to sort this out, smooth changeovers. Short trips even after stopping does not correct this issue.
(d) When the car was on the lift it appears that it does not engage into 4WD. The centre prop shaft does not rotate at all, only front wheels do.
Spoke to a Nissan Dealer and they have no clue regarding the transmission or vibration issues. Numerous gearbox repair shops have indicated that the TCM does not have to be reset/programmed. The current mechanic who has sorted the non start issue told me his gearbox repair specialist is adamant the the TCM must be reset. Again, a costly exercise I would like to avoid if it does not sort the issue out.
Diagnostic only shows error codes for cam sensor P0340 and Fuel consumption has been at around 9l/100km combined.
This car is in strong contrast to my 2005 20l manual transmission on which I never spent money on except for service and tyres, 140 000 km of happy motoring.
Any advice or assistance in sorting the vibration and transmission issues would be highly appreciated.

Thanks in advance...
 

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Registered
Joined
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38 Posts
Hi everyone.
I have just joined the forum, live in South Africa and am really in need of advice/assistance.
I recently bought a 2003 T30 2,5 auto realising it needed some work. That thought was an understatement. Car cost around USD3,000 and have spent USD5,200 on repairs already, excluding tyres.
I have replaced timing chain, had a major service, replaced inner and outer cv's, stabiliser links, had transmission overhauled, new fuel pump and alternator, new engine mounts, new throttle position sensor and have had 4 auto electricians try solve a non start issue with car standing for 2 months. Very expensive exercise.
1. Non start eventually fixed - After replacing cam and crank sensors 3 times with OEM from Nissan, car would only start after cranking 30 plus times and many backfires. Read on a forum that loosening the cam sensor and rotating to the 2 o'clock position lets the car start. Sure enough, it worked. Once started I rotate back to its normal position and tighten bolt. The car would start numerous times during the day but next morning same issue, had to rotate cam sensor again. I have now taken the car to a different mechanic who seems to have sorted the issue out. Appears the sensor did not penetrate deep enough by about 1mm. He sanded the exterior sensor housing down by about 0,8mm and problem gone, starts first time every time. Fuel pre-ignition smell also gone.
2. Vibration problem - at around 120km/h, the steering wheel starts to shudder. This can last from 3 minutes to 10 minutes then suddenly goes away and the ride is smooth and enjoyable. Have done alignment and balancing at 4 different places within a week. Does not solve the issue. Tyres are brand new Cargo Marathons. As mentioned above, have done work on suspension and cv's. Rims are not buckled and tyres do not appear to be out of round. Have had steering checked, all good, wheel bearings all good.
3. Transmission - Spent around USD1,100 to have the transmission overhauled.
(a) Car shudders when shifting from neutral to drive. When I need to stop I shift back to neutral to not feel the shudder. Engine and transmission mounts are new OEM.
(b) Car shudders when accelerating from about 60km/h to 80km/h and then disappears.
(c) Driving for first 100km or so, a slight touch on the accelerator causes a shift down without any power, seems to lag and hang until I release accelerator or depress deeper to force actual changeover. Stopping the car for 10min or so and then driving seems to sort this out, smooth changeovers. Short trips even after stopping does not correct this issue.
(d) When the car was on the lift it appears that it does not engage into 4WD. The centre prop shaft does not rotate at all, only front wheels do.
Spoke to a Nissan Dealer and they have no clue regarding the transmission or vibration issues. Numerous gearbox repair shops have indicated that the TCM does not have to be reset/programmed. The current mechanic who has sorted the non start issue told me his gearbox repair specialist is adamant the the TCM must be reset. Again, a costly exercise I would like to avoid if it does not sort the issue out.
Diagnostic only shows error codes for cam sensor P0340 and Fuel consumption has been at around 9l/100km combined.
This car is in strong contrast to my 2005 20l manual transmission on which I never spent money on except for service and tyres, 140 000 km of happy motoring.
Any advice or assistance in sorting the vibration and transmission issues would be highly appreciated.

Thanks in advance...
look.... im not trying to be critical here but honestly, the only advice thats relevant to this train wreck of an exercise if that you need to find MUCH better mechanics. the ones that are doing your work now should be in some other line of work...
 

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Registered
Joined
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72 Posts
Hi everyone.
I have just joined the forum, live in South Africa and am really in need of advice/assistance.
I recently bought a 2003 T30 2,5 auto realising it needed some work. That thought was an understatement. Car cost around USD3,000 and have spent USD5,200 on repairs already, excluding tyres.
I have replaced timing chain, had a major service, replaced inner and outer cv's, stabiliser links, had transmission overhauled, new fuel pump and alternator, new engine mounts, new throttle position sensor and have had 4 auto electricians try solve a non start issue with car standing for 2 months. Very expensive exercise.
1. Non start eventually fixed - After replacing cam and crank sensors 3 times with OEM from Nissan, car would only start after cranking 30 plus times and many backfires. Read on a forum that loosening the cam sensor and rotating to the 2 o'clock position lets the car start. Sure enough, it worked. Once started I rotate back to its normal position and tighten bolt. The car would start numerous times during the day but next morning same issue, had to rotate cam sensor again. I have now taken the car to a different mechanic who seems to have sorted the issue out. Appears the sensor did not penetrate deep enough by about 1mm. He sanded the exterior sensor housing down by about 0,8mm and problem gone, starts first time every time. Fuel pre-ignition smell also gone.
2. Vibration problem - at around 120km/h, the steering wheel starts to shudder. This can last from 3 minutes to 10 minutes then suddenly goes away and the ride is smooth and enjoyable. Have done alignment and balancing at 4 different places within a week. Does not solve the issue. Tyres are brand new Cargo Marathons. As mentioned above, have done work on suspension and cv's. Rims are not buckled and tyres do not appear to be out of round. Have had steering checked, all good, wheel bearings all good.
3. Transmission - Spent around USD1,100 to have the transmission overhauled.
(a) Car shudders when shifting from neutral to drive. When I need to stop I shift back to neutral to not feel the shudder. Engine and transmission mounts are new OEM.
(b) Car shudders when accelerating from about 60km/h to 80km/h and then disappears.
(c) Driving for first 100km or so, a slight touch on the accelerator causes a shift down without any power, seems to lag and hang until I release accelerator or depress deeper to force actual changeover. Stopping the car for 10min or so and then driving seems to sort this out, smooth changeovers. Short trips even after stopping does not correct this issue.
(d) When the car was on the lift it appears that it does not engage into 4WD. The centre prop shaft does not rotate at all, only front wheels do.
Spoke to a Nissan Dealer and they have no clue regarding the transmission or vibration issues. Numerous gearbox repair shops have indicated that the TCM does not have to be reset/programmed. The current mechanic who has sorted the non start issue told me his gearbox repair specialist is adamant the the TCM must be reset. Again, a costly exercise I would like to avoid if it does not sort the issue out.
Diagnostic only shows error codes for cam sensor P0340 and Fuel consumption has been at around 9l/100km combined.
This car is in strong contrast to my 2005 20l manual transmission on which I never spent money on except for service and tyres, 140 000 km of happy motoring.
Any advice or assistance in sorting the vibration and transmission issues would be highly appreciated.

Thanks in advance...
So this T30 is definitely 4WD but the propeller shaft that runs to the rear end "never" turns? That propeller shaft is live, in other words it is always (supposed) to be engaged, so it should be turning whenever the front wheels are turning. Put the vehicle on a hoist or at least with all four wheels off the ground, car in neutral, engine off, in 2WD (not really relevant), turn the propeller shaft by hand or with a tool and watch the rear wheels; they shouldn't turn. The switching into 4WD on the T30 is done by the electric controlled coupling (ECC) that is in front of the actual (rear) differential; the ECC input flange connects to the propeller shaft. That rear unit (ECC plus differential) Nissan refers to as the 'rear final drive". If the propeller shaft is not turning when the front wheels are (and I'll assume it's not simply disconnected at the front) then that is not a good sign because that says that there is a real problem in what Nissan calls the "Transfer" or "Transfer Assembly"; you may see it referred to as a 'transfer case' although I don't think that is strictly correct here. For the propeller shaft to be dead I can only assume that there is a serious internal problem in the Transfer Assembly, which is hard to imagine, but it sounds like the output shaft pinion gear is either stripped or missing some teeth, clearly a very bad mess. I'm attaching some of the important pages from the service manual section "Transfer". I would think that some or all of your weird drive train behaviour could be attributed to a really messed up Transfer Assembly. So for example the shutter at 120 km/hr could be because the electric controlled coupling is seized (I had that problem) and periodically the Transfer output shaft does engage for a while so you are travelling briefly with the rear end locked in at speeds well beyond where that is normally permitted by the 4WD control unit. If you do the first test I suggest, seeing if turning the propeller shaft by hand causes the rear wheels to turn, then you may have the explanation for why it seems much of your drive train, starting with the transmission, was/is a mess. My guess at this point is that the previous owner was driving for a long time, including at high speeds, with the ECC seized on and that puts a lot of stress on the drive train. Something will get damaged, worn or broken. The ECC has two sets of wet clutches, a control set and the main set. They are a number of thin metal disks with an abrasive (I've been told bakelite) bonded to them. The clutch is engaged just like the clutch in a manual transmission, with the disks being compressed between metal plates that have tabs that slide in grooves in the outer shell of the unit. The lubrication for the clutches comes from the oil in the differential that can leak through the (open) input shaft bearing of the differential. That actually requires that the oil level in the differential is at least up to the output shaft bearing. The bakelite lining of the disks does in time wear off and produces a very fine, hard grit and in my case that grit got into the ECC input bearing and eventually locked it up solid. The ECC is not serviceable and is pressed together with no ability/provision to disassemble it. I did an autopsy on mine with a lot of work using an angle grinder and cut-off wheels; that unit is heavy and the stainless is thick and tough.
I have no idea what "resetting" the TCM on the T30 would be. These vehicles were, from what I can determine, the last Nissans (along with the 2006 Sentras in the US and Canada) that did not have a true CAN1 or CAN2 computer control network (the service manual seems to use the term "CAN" in a generic sense because diagnostic units know what system the vehicle uses and it's not the "CAN" standard). The only real "computer modules" in the T30 are the ECM and the TCM and by today's standards they are not very sophisticated.
I certainly would agree with another poster that you seem to be dealing with some pretty incompetent "professional" mechanics. These T30s are a little odd in places but they are not that complicated relative to most vehicles built in the last 10 years.
 

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