Rybear458

If you have a transmission with problems that require a rebuild (worn synchro rings, a stripped gear, etc.), is it better to go through with the rebuild (probably through an experienced shop since tranny rebuilds are expert tier work), purchase a used transmission with less miles, or purchase a brand new transmission? This question is not meant to help me with a specific problem; instead, it is meant to reveal the pros and cons of a rebuild vs. a used purchase vs. a new purchase.

Additionally, if going through with a replacement, is there a purchasing guide as to which transmissions will fit which years? I've looked around this site for a while and haven't found a concise list with serial numbers and compatibility. It would also be helpful to know which transmissions are better, ie. have addressed issued found in the early Z years and are less likely to fail.

Thank you for any input on these two questions.

dkmura

iTrader: (64)

To address the main question in this thread, assessment is likely the key. If the shop (or independent tech) you select can provide a reasonable accurate repair estimate, it becomes a question of economics. If you've trashed the entire tranny, it's likely better to find a used or rebuilt unit. For what you've described here (new syncro rings and a gear), it's likely more cost effective to repair the tranny.

There's no purchasing guide that I'm aware of for Z33 trannys, despite the knowledge that the CD009 had some useful upgrades. The '03-06 tranny cases are different than the '07- 08 trannys that match up with the HR engines.

I'm sure there are others here who can fill in the details better than me, but regular maintenance scheduling and the right products (hint: Redline MT85 or OEM lubricants) always help stretch the useful life of your tranny.

Atreyu'z 350

That question solely revolves around you budget. Your purchasing guide is goggle, and the CD00A is the latest model in production with the most current updates.. Visit Z1Motorsports.com

Rybear458

Thanks for the info. I thought there would be a guide out there that showed compatibility by serial numbers or part numbers. Maybe I can make that guide if I find the information. I know that the starter motor is on opposite sides for the DE vs the HR, so maybe I'll just use that to know if the transmission will fit. I think I'll check to see if I already have a CD009 or CD00A (I know very little about what the previous owner did to the car), and if I have one of those, I'll rebuild it, but if I don't, I'll go ahead and replace it with an updated tranny.

If anyone else has any insight or personal experience, I would love to hear it.

CK_32

iTrader: (1)

Depends really. Some can be rebuilt easily and semi cheaply. Other are a total loss and should be replaced.

Also depends if it's an off the shelf trans or a custom. In short you really just need to weigh your personal options and go with the best choice.

Atreyu'z 350

What year is your Z?.. You don't have the 'A', and I'm going to bet that you don't have the '9'. Probably the '7' or '8'.. Generally, it's the same transmission from year to year with just some minor mechanical updates.

dkmura

iTrader: (64)

Early production Zs may have newer spec trannys as well. My pre-production Z was still operating well when Nissan put out a campaign on transmissions a few years after purchase. Lots of early Z enthusiasts were having hard shifting and the new spec tranny with triple cone synchronizers on first and second gears were offered. That was plenty of reason to take mine in and get the upgrade for free.

Rybear458

My Z is a 2008 6MT. I just crawled under the car, and the casting on the side of the transmission says "CD5 #1". I'm thinking I'll go ahead and invest in a new transmission. My specific problem is that my 5th and 6th gears grind during shifting. If I deliberately move the shifter slowly, I can get in gear without grinding, but if I shift fast, it grinds and may not go in. My best diagnosis is that some of my synchro rings are bad. I have already done a shifter plate realignment with no change in shift quality.

dkmura

iTrader: (64)

Before you do anything as drastic as swapping trannys, here's a suggestion: try doing a simple change of tranny fluid first. Use Redline MT85- it's a synthetic Gl-4 lubricant with sufficient friction engineered in to allow syncros to work well. It's used in both my street Z and race Z (different gearboxes) with excellent results.

Rybear458

I appreciate the suggestion. Let me give a little background and ask one question. I bought my Z in the summer of 2015. At the time, the gears were already grinding (I got a really good price because of it). That winter, the clutch slave cylinder went out. I dropped the transmission and replaced the slave cylinder with the upgraded ZSpeed Performance one. During that job, I did a fluid change with Royal Purple Synthetic Oil 75W-90. I had seen a post on my350z that suggested either it or Redline MT85. This Royal Purple stuff claims to be for both GL-4 and GL-5 applications. It also talks about some "cushioning molecules" that absorb gear impact and minimize wear, and it says it's non-corrosive to soft metals, so it is safe for transmissions with synchronizers. All of that to ask, is this Royal Purple Synthetic Oil on par with the Redline MT85, as in, is Redline significantly better than Royal Purple? The gears were grinding both before and after I did the fluid change, and seeing that I have the CD5 model makes me want to upgrade to the CD009 (unless there would be no significant gains).

MicVelo

As was stated, the Redline MT-85 is the only aftermarket fluid that has sufficient friction modifiers in it; making it suitable for the Nissan transmission. The two most accepted replacement fluids are Nissan OEM or MT-85. Royal Purple is hype - but probably not "bad" for the tranny. (Although for the life of me, can't see how a fluid could meet both GL4 and GL5 spec.)

FYI: Your '08 ALREADY HAS a CD009 but IS NOT THE SAME as the CD009 for '03-06 DE models. The "CD5" nomenclature on the trans case refers only to the physical housing type as in (C)ase(D)esign, starting with CD0, CD0 #2, on up to CD5 (the HR/VHR trans case).

The triple numeric (now alphanumeric) designations, e.g. CD001, CD009, CD00A (newest DE replacement unit), refers to the internal transmission structure by generation with the newest ones having improved internals).

Ref: https://my350z.com/forum/engine-and-...l#post10700618

Problem you may run into in searching out a CD009 for the HR engine is that they were only available for two years in the Z33 chassis so finding a good used one may be tough. I believe Z1 and ConceptZ (vendors here) both offer the correct CD009 transmission for the HR engine as well as the DE versions).

However, know that the CD009 from a Z34 *FITS* (as in "bolts up" to the back of the engine) but I cannot say with any definitiveness whether it's plug and play as the shifter bracket, shifter, output shaft MAY be different. (I seem to remember looking something up for my Z34N that made me think there was a difference.)

Rybear458

Thank you, that is exactly the information I was looking for. I agree with you that it seems unlikely a single fluid can meet both GL4 and GL5 standards, but I had seen several posts about people using it successfully, so I decided to give it a try. Probably a mistake. I will definitely be switching to Redline from now on.

And I didn't realize there was a difference between the CD# and CD00#. I am aware that the DE trannys are different from the HR trannys (bell housing bolt pattern, starter motor placement, etc.), but I didn't realize the HR cars came with a CD009 from the factory. That was the information I was having trouble finding. I had already found that Z1 carries new transmissions for both DE and HR engines. But now I'm thinking about having my tranny rebuilt with new synchro rings. I'll need to compare prices first.

Thank you so much for the info.

nizmo_0385

iTrader: (5)

get a new one from Z1 and be done with it. I seen a guy on Instagram freshkicks put a z34 trans into his HR 350z and it was plug and play but the gearing was different.