Is the G35 6 speed transmission a good option for a VH45DE in a Q45?

[qsiguy]

I have the opportunity to acquire a 6 speed transmission from a G35 but I need to find out if anyone has any technical info on this transmission and specifically how good a match it will be with the VH45? Is this a strong transmission? How close is it to the size of the 300ZX transmission like Wes used in his Q45?

I'm not too concerned about the adapter but are there any off the shelf adapter plates for it? If not I can get one made, I have an engineer at the office that is a wiz on CAD and we can send it to a machine shop or water jet cutting shop we use all the time to get cut out. What I am concerned with is the fitment in the Q45 and how strong it will be.

Any thoughts?

[EMK]

To answer as much ad I can.... As far as a match to the engine it depends on your rear end and preference. In my case (q45 rear 3.54) I think so but there are those who would argue that. As far as technical info the 6 speed is a closer ratio and a higher overdrive than the 5 speed .753 (5speed) and like .793(6 speed). Don't take that for being 100 percent accurate just yet still haven't found the old thread that housed this info. I'm tossing around the idea of welding or creating an adapter plate. Last I heard the only adapter plate make for this combo hasn't been made for a while and it spaced the flywheel and trans back about an inch. Thus the reason I haven't tried to digg that up. As far as size goes it's a little fatter than the KA trans which is all I have to comepar it to but the roteounted shifter is what makes it look impossible to get lined up with the hole on the floor but it's been bot before too just not with this engine.

Anyway I'll post the links to the old threads that had all the info asap.

[T45]

The TT 5 speed is tough and cheap. I picked mine up for 300. The only experience I have with it is watching my buddy shift one in his 350Z, grinding, miss shifts, etc. I was not impressed.

[gs14racer]

z33 transmission's are notoriusly weak, suffer synchro problems etc, thats why they are so cheap, z32 is where its at.

[Q45tech]

Based on history it appears that the middle 90's was the peak of mechanical strength, metallugy, and expense is no object in world auto technology.

Due to inflation/cost cutting it has been down hill since OBDII.

[EMK]

Information from these threads alreaady covering this topic

zer...tio-s

zerothread/293677

zer...ption

zerothread?id=340603

That will at least give you the ratios exactly and the previous arguments for why one is better that the other.

[qsiguy]

That is good info to know. Definitely do not want to spend any time and money on a weak transmission. That would completely defeat the purpose of the swap.

How about a Supra transmission? Last time I spoke to a buddy that owns a trans shop he told me we should put one he had in my car.

[elwesso]

supra trans and TT trans are both good, and the nice thing about supra trans is it has a removable bellhousing...

downside to supra trans is you need a custom flywheel.

[elwesso]

For the G35

1st 3.7942nd 2.3243rd 1.6244th 1.2715th 1.0006th 0.794Reverse 3.446

Also note that final drive is the same as Q45, 3.54!

[tempestas]

I have used and rebuilt both. The TT is stronger no doubt. It is really only the 2003 models that had bad syncro problems, both 350Z and g35. It is noticed less in the g35, they think because the people generally don't beat on them as hard. I have a 03 track model 350z and the first owner didn't track it, trans was fine when i bought it with 55k miles on it. I took it to 2 track days and 3rd gear syncro totally ate it. I replaced 3rd gear syncro only, beacuse it was my daily and I didn't have time to mess with other things. I knew it was a syncro so I ordered one and pulled it. When i got it apart i found 4th was worn pretty bad too, couldn't wait a week to order another syncro, so i just stuck 3rd in and its been fine, but 4th has started to grind sometimes if i don't baby it.

The truth is z32 trans has syncro wear problems too.. but not as bad at 03 6speeds did. As far as pysical components, z32 is built stronger.

350z has higher quality 2 pecice syncros on 1st and 2nd that do fine (they cost 150 each instead of 40 each) and when they had issues on 3rd and 4th, they started using 2 price on those as well 04 and up. 5th and 6th still have the plain jane sycnros. I don't why they wear faster than normal, as the z32 and such used 1 peice as well, but i would guess they are thinner or are too loose brand new and just wear out too fast.

All and all, syncros wear and can be replaced, but its a difficult job and needs some somewhat special tools. If your buying used trans, you have no idea, there are alot of z32 trannys out there with grinding issues as well.

[XJared]

Having replaced and rebuilt both, they both have their upsides and downsides. Both have synchro issues (z32 in 2nd, z33 in 4th and 6th), but after you get the later model revisions, they both are ok. The z32 actually superceded to a completely different countershaft, the z33 to a completed different design. The CD009 is the z33 trans to have. The 6sp is good if you want another mid range gear since 5th is the 1:1 instead of 4th. Because of technology generations, connectors, flywheel depth etc.. the choice for easiest swap is for the z32 trans on vh and z33 on vk.

[qsiguy]

How do the measurements compare? Does the shifter come up in the right location?

[XJared]

I don't have a z32 trans in front of me to compare, but the z33 and z32 both have a remote shifter that is well behind the trans, i think the z33 trans is built to have the engine a little farther forward though, from memory I think it's extension is a little longer.

[tempestas]

they are pretty close, but id say the 6 speed has the shifter a bit farther back as XJared said. The good thing about a remote shifter is it is pretty simple to move it however you need to make it fit. z33 does have an aluminum mount though, that would be a little harder to modify.

[XJared]

This guy makes mounts that move the 6sp shifter forward:

http://www.vq240z.com-a.googlepages.com/

[qsiguy]

Thanks for that link. His adapter moves it about 4" further forward. He's asking $200 for his but it doesn't look too difficult to do yourself.

I currently have a 4.08 rear end but I'm thinking about putting the stock one back in for two reasons, first I think there may be a problem with it and second, I think I liked it better than the 4.08.

Tough decision to make.

[Nealoc187]

I have a lot of experience with 350z transmissions and have posted numerous analysis threads on my350z. I built race and high performance transmissions for 3.5 years, my former boss has been doing it for like 15 years. Here are a few of the threads about our 350z trans experiences, including the aftermarket gears we helped pioneer and test in conjunction PAR just recently.

Through their iterations, as you will read in the threads, nissan went from single, to double, to triple cone synchronizers on 3rd and 4th gear.

What it boils down to is that 3rd gear is what breaks under high torque applications when lots of cycles are applied to it. We pioneered a solution. Fortunately the mode of failure is such that you won't destroy the rest of the transmission with the way 3rd gear synchro disc separates from the main body of the gear. That's a good thing.

If you're planning on putting more than 500wtq down and drive the car a lot then I'd consider upgrading it, if you go with the Z33 trans. If you don't drive a lot or don't plan on putting down that much power, you'll never break it. Synchro problems were common back in the early iterations of the trans, however the CD008 trans I've worked on has no such problems and is routinely shifted very hard and at high rpm (the death knell for synchronizers) and the CD003 trans which was briguymax's backup trans had the same done to it, no problems.

http://my350z.com/forum/forced...t=TRE

http://my350z.com/forum/forced...t=TRE

Aftermarket gears finally installed and tested

http://my350z.com/forum/forced...t=TRE

About the Supra trans, if you're talking about the Getrag V160 used in the MKIV, it's an incredibly strong transmission, with crappy synchronizers that like to wear out and also like to wear out the synchronizer teeth on 2nd, 3rd gear and 4th gear - necessitating gear replacement sometimes and hub/sleeve assembly replacement often. The synchronizer teeth are just too small and they get worn down very quickly (as they are on all getrag transmissions). I've built a number of these for race duty as well, and they are an absolute nightmare to work on. They are a thing of beauty, but I dread working on them. And they're expensive.

Modified by Nealoc187 at 6:05 PM 10/19/2009
Modified by Nealoc187 at 6:06 PM 10/19/2009

[tempestas]

since few people actully rebuild thier trans... i have a 03 track that ive already had to replce 3rd gear syncro on (single) and 4th has gone now, i have never seen a later model trans, so, is it possible to put the later syncros in the early trans? is the hub different?

[jtmroczk]

This guy makes mounts that move the 6sp shifter forward:

http://www.vq240z.com-a.googlepages.com/

ah crap, haha wish i saw this last week. 4" would be good 6 would be perfect.
i think that puts it at the back of the stock shifter slot. would still need to take the bend out of the shifter.