Clutch In, Gears Grinding

[Galois]

good morning people!

yesterday afternoon i noticed a couple of my gears will grind when the clutch is in. particularly 1st and second. so if i'm braking and changing down, as the gearstick goes nicely into second and then the grinding starts, all with the clutch pressed to the floor.

its the same if i put the clutch in and put it into second while cruising along. it isn't every time, just most lol.

also, when changing gears in normal driving there is often a slight grind when the clutch is below the pick-up point. the gear goes in but the sound is a bit like trying to change gear with the clutch out... just shorter.

im guessing the clutch or transmission oil is getting old. i have no idea when the clutch was last replaced as the car has no log books. i was told that the car had had its 100km service and had 125km on the clock now. that said, i don't know what was done in the "100km" service.

did a quick search and most problems along the lines of grinding gears seems to be grinding when changing into the gear.

thanks in advance

[Birds]

Most likely a worn second gear synchro if it doesn't really occur in other gears.

Less likely, but can certainly be responsible, clutch dragging due to lack of pressure (can be caused by air in the lines, may need bleed or slave/master cylinder replaced, worn pressure plate...).

[Galois]

thanks for that. is there any way of checking those things?

[gfunkk]

if its the other gears that are giving a slight grind then yeah, when last was your clutch fluid changed? over a year o2 gets into it and it wont have as much pressure when you put your foot on clutch

if its done 125xxx and you havent changed your clutch your due pretty soon

so might be a good idea to do a HD clutch upgrade??

[Galois]

so clutch wouldn't have been changed during the 100k service? the clutch fluid is due for a change then, i'll look for a diy on that...

[mad082]

the other possible cause for this is much more serious. i know a few skylines that have had this issue. it is a gearbox out job, but the actual problem doesn't cost much to fix.

inside the gearbox there is a piovt bolt that the clutch fork pivots on. especially when heavier clutches are put in, this bolt gets extra stress on it. i've seen various ways for this pivot bolt to break. in my car it snapped clean off at the base, but a mate of mine had the mushroom head break off. this then causes the clutch to not engage fully, so the gearbox still has a bit of load on it when you try to change gears.

[Birds]

Hey Marc, where is that guide you made for lubricating the input shaft retainer plate / clutch fork / thrust bearing area?

[Galois]

yeah, that would be really useful!

i was planning on doing a transmission oil change soon too, not sure if it'll help...

[mad082]

Hey Marc, where is that guide you made for lubricating the input shaft retainer plate / clutch fork / thrust bearing area?

somewhere back in 2006, LOL. hang on i'll go looking

[mad082]

here it is. nearly 4 years ago now. not really a DIY but has a pic of where you need to access the pivot bolt to try lubing it up. with a small torch you could also inspect the bolt for signs of damage.

http://www.skylinesaustralia.com/forums/in...t&p=2216865

[Galois]

just took the car for a drive, weirdly it is only about 1 in 4 or 5 gear changes that the gear makes a little grind when moving into place, same with the 2nd gear grinding. does that mean anything? lol

cheers for that mad, i'll get under and have a look when i can.

[Birds]

yeah, that would be really useful!

i was planning on doing a transmission oil change soon too, not sure if it'll help...

Could help, depending on the viscosity you use. Might want to try Redline as a bit of a bandaid solution, but if it's a synchro related issue then this will only mask it until you get the synchro changed - it will just get worse and worse over time.

just took the car for a drive, weirdly it is only about 1 in 4 or 5 gear changes that the gear makes a little grind when moving into place, same with the 2nd gear grinding. does that mean anything? lol

cheers for that mad, i'll get under and have a look when i can.

Can still be synchro issues mate - thing about synchromesh is that if you match the revs well then you won't notice their wear. Shame you're in Sydney or I'd get you to bring it past the workshop for a testy

[Galois]

ok, so im going to look for a clutch fluid replacement, what fluid do i use? cheers

[mad082]

is there anything on the cap that says anything about requiring a dot fluid or anything like that? i'm going to take a stab in the dark (because i don't know that answer), but wouldn't it just be like brake fluid? it essentially performs the same task.

[Cowboy1600]

Could help, depending on the viscosity you use. Might want to try Redline as a bit of a bandaid solution, but if it's a synchro related issue then this will only mask it until you get the synchro changed - it will just get worse and worse over time.

Can still be synchro issues mate - thing about synchromesh is that if you match the revs well then you won't notice their wear. Shame you're in Sydney or I'd get you to bring it past the workshop for a testy

Where's your workshop?

My GB grinds pretty badly on 3-4 shift and occasionally into 2nd.

I'm pretty sure it's syncros, but wouldn't mind an expert having a squizz over things that can be seen before I start planning any large scale fixes.

[Galois]

argh, so bought the gear oil (castrol vmx-m, wanted sin 75 but didn't want to pay, will replace this soonish when funds allow), mixed in a 125mL tube of nulon g70 (g90 doesn't exits it seems), bought castrol super dot 4 brake fluid for the clutch too but didn't get up to that, because i COULDN'T GET THE TOP SCREW UNDONE!!!! Spend so long trying but gave up with lack of light... will take it to a mechanic tomorrow, but i may have fkd up the grub screw...'

if the grub screw is stripped, how can it be undone?

[Galois]

i got under the car the other day but couldn't feel the end of the pivot bolt for the clutch fork.

is there any trick to it? had my finger in a good 8cm but no luck...

[mad082]

you were probably still a few cm from it. use a screw driver to pull the seal to the side and then shine a torch in there and have a look

[Galois]

A month or so late, but changed the clutch and gearbox oil and problem completely disappeared. Apparently the clutch was really fkd.

[t_revz]

did u end up picking up another bellhousing after the mishap couple months ago? or did the hole get patched?