Problems with Patrol five speed gearbox
Posted: 17 Dec 2009 16:16
I have had two problems with my Nissan five speed gearbox which came from a TD 42 Patrol with about 65000 km on the clock. The first problem was the the inablility to engage fifth gear which occurred at about 80000 km and the second was trouble with the reverse idler gear which occurred a couple of thousand kilometres later.
The second problem occurred when I was travelling slowly down a steep incline in the Transkei. I heard a rattling noise which we found later was the reverse idler gear bouncing around in the box. We found that the idler gear shaft had moved forward out of position and released the idler gear. The shaft is located with a small plate that engages a slot in the shaft. The bolt that holds the plate in position had come loose and presumably was also circulating in the back part of the gearbox. Luckily I heard the noise and stopped immediately.
With the help of some friends we removed the gearbox.
We took off the top access plate and the side PTO plate and could then get at the shaft and gear, but not the locating plate and bolt which was in the back part of the box. Unfortunately we could not get the idler gear out of the box without removing the main shaft with all the gears, which we were reluctant to try.
We managed to get the idler gear and shaft into their correct position but with the shaft back to front with the end protruding forward from the bearing and with the slot exposed. We then carefully drilled a 4 mm hole into the side of the gearbox opposite the slot in the shaft. This was the only way we could think of to ensure that the shaft could not slide forward again.
We cleaned out the hole and epoxied the drill into position with the end of the drill in the slot in the shaft.
After washing out the box with some diesel and replacing the oil we got the gearbox back into the vehicle.
I drove about 1500 km home with no problem.
I had the gearbox overhauled but was unable to get a satisfactory explanation neither why the idler shaft had come loose nor why I had been unable to engage fifth gear.
Has anyone else had similar problems?
The second problem occurred when I was travelling slowly down a steep incline in the Transkei. I heard a rattling noise which we found later was the reverse idler gear bouncing around in the box. We found that the idler gear shaft had moved forward out of position and released the idler gear. The shaft is located with a small plate that engages a slot in the shaft. The bolt that holds the plate in position had come loose and presumably was also circulating in the back part of the gearbox. Luckily I heard the noise and stopped immediately.
With the help of some friends we removed the gearbox.
We took off the top access plate and the side PTO plate and could then get at the shaft and gear, but not the locating plate and bolt which was in the back part of the box. Unfortunately we could not get the idler gear out of the box without removing the main shaft with all the gears, which we were reluctant to try.
We managed to get the idler gear and shaft into their correct position but with the shaft back to front with the end protruding forward from the bearing and with the slot exposed. We then carefully drilled a 4 mm hole into the side of the gearbox opposite the slot in the shaft. This was the only way we could think of to ensure that the shaft could not slide forward again.
We cleaned out the hole and epoxied the drill into position with the end of the drill in the slot in the shaft.
After washing out the box with some diesel and replacing the oil we got the gearbox back into the vehicle.
I drove about 1500 km home with no problem.
I had the gearbox overhauled but was unable to get a satisfactory explanation neither why the idler shaft had come loose nor why I had been unable to engage fifth gear.
Has anyone else had similar problems?