Post by Stu on Jul 16, 2015 23:05:35 GMT
Hi fellow Auto fans,
I've been dismantling a 1275 auto box I acquired recently and saw lots of metal fragments in the bottom of the box. I found it to be due to some major damage to the gear train. I was wondering if anyone knew what could cause such serious damage to the planetary gear splines? There are also missing teeth to the reverse output gear which meshes with the planetary gear.
I think it might be due to misuse, but could also be due to tooth breakage of the reverse output gear leading to the wear on the planetary gear spline, but cant be sure.
For the teeth to break like that I would suspect the reverse gear has been selected too early from drive, or the box has simply been operated too roughly and without due care on up / down-changes.
It could be something else but the gear train is toast for sure
Interestingly though, I can report that this box, a later one with a park facility, has a different valve block from the standard no park box. It houses a lever which engages into a toothed sprocket on the end of the forward clutch for park when selected. The selector shaft has a very short coned shaft around it which, when engaged, pushes the park lever to engage into the sprocket to provide the park. It basically locks the gear train in position. I assume the selector would need to be in 'N' to allow the car to be started due to the inhibitor switch, which would disengage Park and allow the gear train free movement ready for drive or gear selection.
The more I work on these boxes the more I like them, its just sad to find damage. I'm still working on trying to dismantle the gear train, but I need a special service tool to remove the gear spindles, and I cant for the life of me get the locking ballbearings out. ''Give the gear train a light tap with a hide faced mallet to jar the locking ball out'' says the manual ...... Yeah right