Gearbox Clutch CVs CV joints gear change reluctance
HarryMann: Slow into second when cold or synchromesh reluctance in very cold weather is fairly common on many boxes and the T25 can suffer this too, particularly as the miles build up and synchro hubs wear. Here's a few tips...
But first of all, what's below assumes the box has the right quantity of oil in it - draining T25 boxes to find next to no oil is not that uncommon. Oil level on Syncros is reckoned to be just less than an inch below the bottom of the filler hole.
Many boxes, not just ours, have this problem, of slow into 2nd when cold, one coming to mind being Lancia FWD boxes of the Betas, Deltas and Prismas. Otherwise, good and (very) strong boxes, but as the comments below make clear, lack of mechanical sympathy over a few years will eventually degrade first of all, 2nd gear synchromesh. As this is the first change-up of the day, when pulling away from cold, if it's dragged into gear screaming & kicking before the hubs can equalize the speeds, or the dog-teeth engage, then wear, even damage occurs. Some also try to rush this gearchange as the rolling speed of the vehicle is slow between 1st and 2nd - some hints follow - learn the foibles of your car/van/truck and drive accordingly.
The problem with getting that change wrong and persisting is making it progressivley worse as the hubs wear and the sharpness wears off teeth of the engagement rings - I'll see if I can't get a good photo to show what happens.
There'a few tricks one is to double-de-clutch - Clutch down and slip it into neutral, let the clutch up quickly as you blip the throttle just the right amount, clutch back down and ease it firmly into 2nd gear (no yanking that lever, just firm pressure). All before the vehicle has slowed down too much, so if going slightly uphill, don't change up too early! So double-de-clutching >> letting the clutch up when the lever is in neutral speeds the gears up again, ready for meshing at the correct speed, whereas just blipping the throttle speeds the engine back up OK, but not the gbox mainshaft as well. It's a technique that takes a bit of learning to be smooth, fast and fluid, but anyone starting their driving in the 50's and 60's ought to be pretty proficient. Another time to use D-D-C'ing is when slowing for a big ratio change, typically up a hill with a Major Road Ahead that requires to be in 1st ready for an immediate take-off. Coming out of 2nd and using just the Synhromesh to force it into 1st is just Ugh! - painful to witness sometimes ;-) Sometimes even, out of 3rd or top and into 1st, after a very rapid braking session. So a blip or the full DDC into 1st can be mighty swush when you get it right.
Another trick, when starting on the flat or downhill, is to take 1st a bit further than normal and go straight and quite quickly into 3rd. With some gearboxes of old, when very cold, you'd virtually have to do this as they would often be far too heavy to drag into 2nd (Lancia Betas, worn out mini boxes), and if you succeeded, then gradual damage described above would occurr - anyone with much mechanical sympathy would soon know harm was being done, as the synchromesh whines and screamed.
When running light, on the flat or downhill, you should be able to simply pull away in 2nd gear. The clutch is designed as a wearing replaceable item, the gearbox isn't! Don't slip it for ages, hardly any wear at all occurs just letting it in quite quickly with the right revs and throttle. On a JX or AAZ diesel lightly loaded, 1st is almost a waste of time on the level anyway.
If you test a vehicle when warmed up and it 'snicks' going up into 2nd or 3rd, this is the reason, someone's been assuming that synchromesh relieves them of the duty of changing gear considerately, just dragging it in regardless of any complaints or reticence to synchronise when cold (or racing the change when warm). Only the best of the smaller and lighter units can usually cope with this. So that snick or reluctance xcan only get worse, unless they really have filled it with (the wrong) highly viscous oil.
Once the baulk-rings and synchro-hubs are worn, there is less chance you will get a good change when cold, whatever the oil, The rear-engine layout necessitates a complex and often well-worn selection mechanism on T25s which doesn't help either - if this is all in good condition it definitely helps the driver feel the box into gear, or realise quickly it is just not interested!
Just don't even try going into 2nd when around freezing outside from a cold start if box is like that... fast idling it a while in neutral might help a bit (never a good idea to slow idle for long periods ~ older engines should be warmed up by driving or fast idled).
(Linkage) Adjustment isn't always the answer unless it's been messed up previously or really worn its bushes. It's really all the joints right throughout the selection mechanism that need to be in good nick, without congealed and dirty grease stiffening it. Checkout this topic:
