My first proper foray under the Green Hornet (GTL)'s chassis last weekend for an oil change (all good - 10W40 for the winter just like Clementine) and a gear oil change - why the hell not, it's likely never been changed before.
When the gear oil comes out it's silvery grey and there is a small plug of sediment atop the drain plug with the consistency of peanut butter (smooth, not crunchy). Clearly I have done a Good Thing: the gears will thank me for it and from now on it will be like driving an automatic with some barely noticeable isotonic exercises for the left arm/leg. I replace the oil with Comma 75W80 mineral gear oil - although I don't recall whether it talks about hypoid gears it seemed to be within the recommended range (the viscosity if not the brand).
However. It is now almost impossible to change down from 4th to 3rd, and 3rd to 2nd, without declutching on the way or inviting grinding noises or a severe clunk to get it back into gear. I don't recall having any trouble at all before the gear oil change but now it's noticeable all the time. Seems to make no difference whether the engine is cold or hot, it's a pig to change down at that critical time slowing into a junction/roundabout etc when you'd prefer the car to behave as you have other distractions.
Having wracked my brain as to oh what have I done, my only thoughts are (a) wrong gear oil or (b) overfilled the gear box - I confess I stuffed the filler plug back in as soon as the second litre was in, more oil is better, right? To address (a) I have now bought some Castrol Classic SAE 80 Hypoy light which will go in this weekend. As to overfilling, I did see a post which suggested that might cause clutch slipping, but I don't seem to have that problem, and changing gears up is entirely unaffected.
My first post so excuse any schoolboy errors - hopefully somewhere in the awesome R4 collective intelligence here there lurks an answer!
When the gear oil comes out it's silvery grey and there is a small plug of sediment atop the drain plug with the consistency of peanut butter (smooth, not crunchy). Clearly I have done a Good Thing: the gears will thank me for it and from now on it will be like driving an automatic with some barely noticeable isotonic exercises for the left arm/leg. I replace the oil with Comma 75W80 mineral gear oil - although I don't recall whether it talks about hypoid gears it seemed to be within the recommended range (the viscosity if not the brand).
However. It is now almost impossible to change down from 4th to 3rd, and 3rd to 2nd, without declutching on the way or inviting grinding noises or a severe clunk to get it back into gear. I don't recall having any trouble at all before the gear oil change but now it's noticeable all the time. Seems to make no difference whether the engine is cold or hot, it's a pig to change down at that critical time slowing into a junction/roundabout etc when you'd prefer the car to behave as you have other distractions.
Having wracked my brain as to oh what have I done, my only thoughts are (a) wrong gear oil or (b) overfilled the gear box - I confess I stuffed the filler plug back in as soon as the second litre was in, more oil is better, right? To address (a) I have now bought some Castrol Classic SAE 80 Hypoy light which will go in this weekend. As to overfilling, I did see a post which suggested that might cause clutch slipping, but I don't seem to have that problem, and changing gears up is entirely unaffected.
My first post so excuse any schoolboy errors - hopefully somewhere in the awesome R4 collective intelligence here there lurks an answer!
