leecifer Posted November 9, 2015 Share Posted November 9, 2015 Hi guys, recently bought a used 2006 350Z with 87K miles on the clock and I've just noticed that the gears crunch whenever I shift into 6th. To be honest I completely forgot the car even had 6 gears so I haven't been using it! Rookie error! Anyway, I've read a few articles mentioning a new gearbox or refurbishing the existing one, new synchro's etc... But none of them seem to mention what the actual fault turned out to be, or the final costs paid for the fix. I've booked in for a diagnostic and health check at my local Nissan dealership to see what they come back with but it sounds like it's going to be a synchro issue from what I've read. The guy I bought it off replied today saying "shift into 6th slower, may need a gearbox oil change on next service", what are the chances that I'm that lucky? Also, shifting slower makes no difference, still crunches. Is an oil change with Molyslip likely to fix such an issue? He also gave me a 6 month warranty with World Of Warranty, which does mention that it covers synchromesh, however I've read these kind of warranties can be pretty poor at paying out. Any input would be appreciated, trying to figure out whether it's worth taking back for a refund or trying to get some compensation for being sold not as described. Quote Link to comment Share on other sites More sharing options...
zebedy Posted November 9, 2015 Share Posted November 9, 2015 I think its just the done thing to put mayoslip in with the oil change. Get a report from nissan and get them to ring the Warranty people to sus out whats covered, and if so, get them to do the work or chose another to do the work. Try the oil change first though I would. See what others on here say?? Quote Link to comment Share on other sites More sharing options...
Ebized Posted November 9, 2015 Share Posted November 9, 2015 Likely to be a worn/weak synchromesh - known issue on Zeds and whilst an oil change + molyslip might help, given the warranty says it is covered why not test that option? Quote Link to comment Share on other sites More sharing options...
Irn Bru Posted November 9, 2015 Share Posted November 9, 2015 I don't think there are many 350's that don't have the notchy crunchy box. Mines is notchy going into 2nd and crunches if I put into 5th to quickly. 2nd gets better when it warms up but 5th only goes in smoothly if I don't rush it. Replaced the oil just after I got and added molyslip but hasn't made any difference. Lazy / slow synchro design and you really just have to live with it or fork out mucho £ for rebuild .............. I've learned to work with mine and it's fine as long as I don't try to ram 5th. Try changing at different revs, double clutching , slower etc........ you will find a smooth way ......providing the synchro is not goosed completely. Quote Link to comment Share on other sites More sharing options...
leecifer Posted November 9, 2015 Author Share Posted November 9, 2015 Thanks for the quick replies folks! I'm booked in with Nissan tomorrow so I'll see what they come back with and make a decision from there. With regards to the oil change, a DIY job or would you recommend a particular specialist? Quote Link to comment Share on other sites More sharing options...
mylo Posted November 9, 2015 Share Posted November 9, 2015 I've noticed a bit of a crunch on mine going into 6th gear too, I'm a recent new owner too and haven't really had a chance to investigate much yet but would be interested to know if you find out much about it. Quote Link to comment Share on other sites More sharing options...
jaffers Posted November 10, 2015 Share Posted November 10, 2015 happens to mine too but only if I've been booting it.... Quote Link to comment Share on other sites More sharing options...
Juggalo Posted November 10, 2015 Share Posted November 10, 2015 I used molyslip in mine because of the 2nd gear issue. I actually used two tubes. Made no difference at all. I then replaced the new fluid with 75w140 - that made it slightly worse. Expensive experiment. What did remedy it, and I mean, it actually cured the problem, was 2:1 of 75w90/5w30 Didn't cure it straight away, it took a few weeks, and now all gears are smooth. I can only conclude that as the boxes wear, they become averse to 75w90. Too thick. I was planning to rebuild the box anyway, hence my experiments, but now it's fixed, I'm happy Quote Link to comment Share on other sites More sharing options...
RobPhoboS Posted November 10, 2015 Share Posted November 10, 2015 Something most people don't mention or realise that made a difference for me was to replace the transmission mount (which deteriorates, sloppy shifting feel etc). I used a poly one, which is probably too harsh for most however Hardrace make a decent rubber version which H-dev sell, or whomever you want to use to supply. Ex: http://www.h-dev.co.uk/product_info.php?manufacturers_id=54&products_id=25700 Just an idea, and worth searching and reading about. Quote Link to comment Share on other sites More sharing options...
leecifer Posted November 10, 2015 Author Share Posted November 10, 2015 So I had a little more experimenting last night... Letting the revs down slightly and slowly shifting into 6th seems to be the way forward, it's by no means a fix but something I can live with at the moment! If things get worse I'll drop it into Nissan for the diagnostic, but I'll definitely try changing the oil and adding in some Molyslip. That's interesting Juggalo, I'll have a read around and see if any one else mentions the oil being too thick. Quote Link to comment Share on other sites More sharing options...
Juggalo Posted November 10, 2015 Share Posted November 10, 2015 So I had a little more experimenting last night... Letting the revs down slightly and slowly shifting into 6th seems to be the way forward, it's by no means a fix but something I can live with at the moment! If things get worse I'll drop it into Nissan for the diagnostic, but I'll definitely try changing the oil and adding in some Molyslip. That's interesting Juggalo, I'll have a read around and see if any one else mentions the oil being too thick. They don't. Believe me. I've read every thread on the internet about this issue lol. Probably an exaggeration, but it felt like it at the time. Quote Link to comment Share on other sites More sharing options...
Tuck Posted November 18, 2015 Share Posted November 18, 2015 I had this exact same situation, 2005 with 65k, 6 month warranty and it was crunching into 6th. When shifting to 6th let the revs drop completely with the clutch in and try shift. If it goes in fine then you have the same problem as me and the box needs work. Long term, the gearbox had to be removed from a local garage, sent away to a gearbox specialist in Glasgow and had to be inspected by the warranty company before the work had been carried out. They refused to pay out (even though sychros are covered apparently) but they put it down to wear and tear so refused to pay out. The garage I bought the car from paid for the gearbox to be refurbished at a cost of £2,000 to them. The fault turned out to be worn sychros in 5th & 6th and it sounds like you have the same problem Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Ebized Posted November 18, 2015 Share Posted November 18, 2015 If things get worse I'll drop it into Nissan for the diagnostic, but I'll definitely try changing the oil and adding in some Molyslip. Alarm bells ringing! Unless you know by good recommendation that the intended Nissan dealer has a good reputation for sorting things out on ZEDs, and sadly there are precious few of them because their guys rarely see our cars in the workshops nowadays, then get an opinion from an independent who specializes in ZEDs - there are quite a few on here and I sure members who are local to your location in Telford can point you in the right direction. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.