Vq35De Gearbox Grind :s

[Seano350GT]

Morning guys,

I have done some research about the gearbox synchro's and can't seem to find any info about individuals that have either replaced or rebuilt their gearboxes.

My car has just clocked 90,000km, i bought the car with 80,000 and it already had this grinding problem but silly me i didn't notice it while driving the car with the seller as i don't think i even got it up to 5th and we had music on... big no no.

Anyway, I have a bit of a grind going from 4th to 5th & from 6th back to 5th. It only happens if i change gears relatively fast, if i do a granny switch it doesn't happen. I know this is a problem that needs to be fixed before it gets worse but i really don't have the time to take the car anywhere (not that i'd trust anyone locally) so i thought i'd come here first and get some feedback.

Has anyone had any experience at all with gearbox issues or synchro's? if so, how difficult are they to replace/fix, how costly is the exercise?

[t5iv]

In Mackay with a busted box... sure that there's a pun in there somewhere.

[PN-Mad]

Yes. Common problem is common.

If you research a bit- it appears on 350zs commonly etc. Its the early boxes that flog out the synchros. Later model cars came with a CD009 box that had improved synchros. You can pick them up brand new in the US for $1700 plus shipping (which will obviously be a lot).

Or you can rebuild it. I don't know if you can retro fit the better synchros into the older box.

http://www.conceptzperformance.com/Cart/description.php?II=2887&Car_Type=NIS350&UID=20121001182501121.210.8.129

[sonicii]

There isn't anything particularly special about these manual boxes, anyone with experience/knowledge of manual automotive transmissions should be able to fix it for you. As for parts, it is the same gearbox as the 350Z, so parts should be available from Nissan. If it is just 5th gear you are having issues with, you can probably just replace the 5th gear syncho cone and baulk ring, assuming you haven't damaged the edge of the gear.

The question is, should you replace anything else while the box is apart? possibly input bearing?? maybe search for other common issues?

Edited October 2, 2012 by sonicii

[Seano350GT]

I gave google a lash and had no real results- But thanks for that insight.

I definitely don't want to spend that sort of money so if i can get it rebuilt, somehow, that would be the way i would go.

[Seano350GT]

There isn't anything particularly special about these manual boxes, anyone with experience/knowledge of manual automotive transmissions should be able to fix it for you. As for parts, it is the same gearbox as the 350Z, so parts should be available from Nissan. If it is just 5th gear you are having issues with, you can probably just replace the 5th gear syncho cone and baulk ring, assuming you haven't damaged the edge of the gear.

The question is, should you replace anything else while the box is apart? possibly input bearing?? maybe search for other common issues?

Good to know that parts can be accessed reasonably easy then if they're the same. That's what i'm trying to determine, i know that my 3rd gear doesn't like it if i change into it anywhere over about 5500rpm quickly. But other than that the box is fine, although the shifting from 2nd back to 1st when the engines cold its a bit rough but i assume thats normal.

I'm just hoping i can find someone local that can have a squizz at it and see what needs to be done, what sort of a job is replacing a synchro and baulk ring as you say?

[PN-Mad]

You rebuild the gearbox if it comes out, not just replace one or two components You also replace the clutch. This will save you service costs down the track- you'd be silly not to. Have to talk to a gearbox place and get a quote.

nuffin like a new box.... ifyaknowwhatimean.

[sonicii]

Depends on cost.. a rebuild normally includes all synchos and baulk rings, and all bearings. My limited experince with Nissan transmission parts suggests you might be looking at more than a new transmission for all these parts and labour to fit them.

In the old days of holden 3sp manuals (with only 2 synchros), it was certainly worthwhile to do a full rebuild every time you cracked it open.

I had issues with 2nd gear synchro in a R31 skyline years ago which also damaged 2nd gear, I just had this gear and and synchros replaced and I was looking at around $1500 in parts. Didn't have any other items changed/repalced and never had any further issues with the tranmsission.

Certainly do a full rebuild if you can justify the cost of parts..

Also, transmission work can be labour intensive, so don't expect just 1-2 hours of labour even if you just replace the 5th gear synchro.

[pv35gt8]

If it is going to cost that much (?) to rebuild, might be cheaper to just source another.

[Seano350GT]

Exactly what i was thinking. Ahh, pain in the ass.

[PN-Mad]

If it is going to cost that much (?) to rebuild, might be cheaper to just source another.

Exactly what i was thinking. Ahh, pain in the ass.

Be aware - you might just be buying someone elses problem - why was it removed?

With the fake Kms on these cars, nobody ever knows how much work its done. Maybe 30,000kms in Aust, and 150,000kms in Japan. How can you prove it...?

[Seano350GT]

Exactly. Really annoyed with myself, i really don't think i changed into 5th at all when i drove it with the seller. It was nearly 8 months ago now i bought it so it's not like i can go back and complain.

Yeah it is a mystery. Have been contemplating selling, but i love it too much to let it go...

[Seano350GT]

Need to bring this alive again, how hard is a CD009 box to find? I'm thinking about saving a bit more cash and replacing the whole box + clutch. I will also be buying a clutch bracket that i was referred to by a mate that's meant to smoothen out 1st to 2nd gear changes.

Later model cars came with a CD009 box that had improved synchros. You can pick them up brand new in the US for $1700 plus shipping (which will obviously be a lot).

I am going to have to research and see if i can find a gearbox cheaper, if not then i'm going to have to fork out the money.

[t5iv]

Out of curiousity, when was the last time you flushed the diff?

[Seano350GT]

Out of curiousity, when was the last time you flushed the diff?

Er.. never. I haven't done brake fluid flush in ages either. Or trans oil, ever.

[t5iv]

Might want to get all that done...

[Seano350GT]

My thoughts exactly, it's just a matter of me getting time to doing it. I had planned to do a flush of brake/clutch fluid yesterday but it was 32 degrees and humid as f*ck so that didn't happen.

[Seano350GT]

So the plan is to replace the above fluids when i get a chance, then see how much of a difference i have. I'm expecting there to be not a lot of change. If so, i will save some money and go ahead with a CD009 from ConceptZperformance, saw a few posts on a 350z forum saying they got it to Brisbane for around $2250 brand new delivered.

My next question is, when i go to swap the tranny over what else is needed to be replaced other than the clutch? I guess it will also be a good time for me to check if my car actually has a Exedy twin plate clutch as the previous owner said it did

[Seano350GT]

Thought i'd post an update.

Starting to lose 3rd gear, went for a spirited drive last night and got up to about 6000rpm in 2nd and couldn't get it into 3rd at all. 5th gear still grinds,

Sourced a CD009 transmission $1699 brand new, 5 hour labour job from my mechanic out the back of my work.

JWT clutch & flywheel combo - $775.

Just under $3000 installed for everything unless i decide i want to tackle the box change myself with a mate or 2. Purchasing the new box next week i have a mate in the states trying to find me a better price than $1699 brand new he said he bought his for $1200 brand new so hopefully i can save a bit more money there.

[scotty nm35]

$3000, not bad. Shame you didn't try the Dextron III though, I think that would have been a cheaper fix... Perhaps it's too late now anyway.