As summer came around the issues disappeared, so I hadn't thought about it anymore until recently. End of summer, colder weather, end of smooth gearbox. Alright, let's get some oil.
I looked up the prescribed transmission oil in the manual, Tutela Car ZC75 Synth, SAE 75W-80, API GL5, MIL-L-2015D.
Alright, thanks for the details. Couldn't get that specific type locally, so I went to find its specification sheet and compare it to other gearbox oils to see which were most similar to the Tutela.
First candidate: Eurol MTF 75W80 GL5 MIL-L-2015D.
Second candidate: Motul Motylgear 75W-80 GL4/GL5 MIL-L-2015D.
Both had in its specification sheet they're suitable for synchromesh gearboxes, are easy on 'yellow parts and plastics', etc. Both their technology boiled down to semi-synthetic. Fine to me.
The Eurol oil is slightly thinner, whereas the Motul oil its viscosity was within a few percent of the Tutela. Bought the Motul.
Changing the oil was easy peasy. Finding a 12 mm hex key in the workshop was the most difficult part.
The old oil had gotten brown, but no metal flakes in it and no burnt smell. Good.
I went for a test drive. Gear stick felt smoother, changing gears felt smoother, gears engaged more rapidly. Half of the time I can shift gears using one finger, even when the engine's still cold.
This morning I had to remove ice from my Panda its windshield for the first time since... March? Great for a test.
Ha, even when cold, changing gears is definitely smoother now! It doesn't feel anymore as if I'm stirring syrup.
Downshifting into second or first gear often still requires double clutching or a bit more effort, but that's no big deal. Having to wait 3 seconds before the gearbox pops into 3rd gear is a problem instead when accelerating. Ah, I'll miss the sound of horns behind me.
Thanks all! :worship:
1. Sticking gear cable / selector?
One cable moves the selector in the gearbox housing forwards and backwards (so 3rd & 4th in the central position are fine).
The other cable moves the selector left and right to access 1st/2nd, and 5th/reverse (mounted on top of the gearbox, circled in image). Could this cable or selector be stiff/worn?
View attachment 218383
Checked both cables, both were good. The left/right movement itself wasn't a problem.
2. Play in the gearbox input shaft?
My transmission used to regularly crunch on downshifts to 3rd. New transmission oil improved it a bit, but a new input shaft bearing has got rid of the crunch altogether.
Gearchange is much smoother and the transmission is noticeably quieter.
I never had difficulty engaging gears, though, so it might not be related to your issue.
There are a couple of ways to check if your input shaft bearing is worn:
- If your car is rattling in neutral with the engine on, but the rattle goes away when you press the clutch (as the clutch plate supports the shaft).
- There's an inspection hole in the top of the bell-housing. If you poke a finger in (with the engine OFF!) and it comes out black & oily, the input shaft seal is leaking due to play in the shaft.
I notice no rattle with the gearbox in neutral. An inspection hole, hmm, I will check next time I open the bonnet, even if it'd only be out of curiosity.
