Gear box CRUNCH
Discussion
Hi all,
My car has recently developed a crunching sound when shifting from 2nd-4th, 5th-4th & 6th-4th.
I'm guessing the 4th gear syncro is very worn.
Car is borderline shed territory, cam belt also well over due and will be looking to change car in the next year or 2 anyway.
I do about 200 miles a week.
What are the chances of getting another 1k, 5k, 10k miles before 4th goes completely?
Car has just about enough torque to be drivable without using 4th. Is this a good idea or over kill?
My car has recently developed a crunching sound when shifting from 2nd-4th, 5th-4th & 6th-4th.
I'm guessing the 4th gear syncro is very worn.
Car is borderline shed territory, cam belt also well over due and will be looking to change car in the next year or 2 anyway.
I do about 200 miles a week.
What are the chances of getting another 1k, 5k, 10k miles before 4th goes completely?
Car has just about enough torque to be drivable without using 4th. Is this a good idea or over kill?
BananaFama said:
2 sMoKiN bArReLs said:
Have you tried double declutching? Might extend the life. (And maybe avoid 2nd to 4th 
)
2nd to 4th is not over straining anything but 4th to 2nd might best be avoided .....)
PH.sausages said:
I'm guessing the 4th gear syncro is very worn.
Not impossible but pretty unusual.Worn synchros most usually occur on 2nd or 3rd gear. Essentially a combination of torque and boy racer driving.
Some drivers think it's "sporty" to wrench the gear stick through fast gear-changes. That leads to accelerated synchro wear, especially if a "short shift kit" has been fitted.
Panamax said:
Not impossible but pretty unusual.
Worn synchros most usually occur on 2nd or 3rd gear. Essentially a combination of torque and boy racer driving.
Some drivers think it's "sporty" to wrench the gear stick through fast gear-changes. That leads to accelerated synchro wear, especially if a "short shift kit" has been fitted.
My missus ruined the gearbox in our V70 D5, she is seemingly unable to change gear slowly, even when pottering round town the gear stick is yanked between gears. Bought her an automatic.Worn synchros most usually occur on 2nd or 3rd gear. Essentially a combination of torque and boy racer driving.
Some drivers think it's "sporty" to wrench the gear stick through fast gear-changes. That leads to accelerated synchro wear, especially if a "short shift kit" has been fitted.
Maybe try some molyslip additive which may improve things / buy you a bit more time.
Holts GM6RA 65ml Molyslip Gearbox Protection https://amzn.eu/d/gNOrToi
Otherwise yeah rev match / double decluch or just block shift and miss it all together.
Holts GM6RA 65ml Molyslip Gearbox Protection https://amzn.eu/d/gNOrToi
Otherwise yeah rev match / double decluch or just block shift and miss it all together.
Edited by Ryan_T on Friday 27th January 08:20
Ryan_T said:
Maybe try some molyslip additive which may improve things / buy you a bit more time.
Holts GM6RA 65ml Molyslip Gearbox Protection https://amzn.eu/d/gNOrToi
Otherwise yeah rev match / double decluch or just block shift and miss it all together.
I've fixed gearbox problems with oil before. The last on was running on a dribble of sludge.Holts GM6RA 65ml Molyslip Gearbox Protection https://amzn.eu/d/gNOrToi
Otherwise yeah rev match / double decluch or just block shift and miss it all together.
Edited by Ryan_T on Friday 27th January 08:20
Family used to have a Citreon GS Club, and the synchro on 2nd and 3rd got worn when the car was about 30 or 40k km. - When I started driving it at 100k km, it was just the same, but you needed to take it slow (ish) going up the gears, and double de-clutching coming down.
After a while I could just drive it without the clutch, but the synchro never changed.
I found out later that the dealership heard the car was towing a large trailer, so changed the oil for a thicker oil - that caused the synchro to run dry. Going back to the oem oil helped, but the damage was already done - I would say change the oil for new, and not go overly thick!
After a while I could just drive it without the clutch, but the synchro never changed.
I found out later that the dealership heard the car was towing a large trailer, so changed the oil for a thicker oil - that caused the synchro to run dry. Going back to the oem oil helped, but the damage was already done - I would say change the oil for new, and not go overly thick!
stevieturbo said:
What car ? what box ?
Obvious thing is to try new, good and correct oil.
Assuming of course clutch etc is working as normal and any gear linkage/cables are good.
MK3 Renaultsport Clio 200, 6 speed manual.Obvious thing is to try new, good and correct oil.
Assuming of course clutch etc is working as normal and any gear linkage/cables are good.
I've heard lots of other owners having similar issues, I suppose mine has done well to do 100k miles before it's started playing up.
I would check out the clutch fluid in the slave cylinder. I once had a TVR that I thought needed a new clutch as it crunched in most gears. First thing I did was to drain the slave cylinder and the fluid in there was like brown windsor soup. Pumped some fresh fluid through and hey presto, it was like I had just fitted a new clutch. I can't understand why it isn't on a service schedule as it only takes a few minutes to do. There must be millions of cars on the road with knackered clutch fluid in the slave cylinder.
PH.sausages said:
MK3 Renaultsport Clio 200, 6 speed manual.
I've heard lots of other owners having similar issues, I suppose mine has done well to do 100k miles before it's started playing up.
aren't those cable operated?May need replacing, but also change gearbox oil, bleed slave/hydraulic fluid. That should see a marked improvement.I've heard lots of other owners having similar issues, I suppose mine has done well to do 100k miles before it's started playing up.
StescoG66 said:
Oil change and some Slick 50 or Molyslip. I didn’t have a crunch but an obstructive gearchange. Both helped immensely.
Any products that might reduce friction, are the last thing you would want.In fact, an LSD type additive/friction modifier might even be worth a try, which increases friction.
But a good oil first.
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