Nealoc187

iTrader: (23)

Just so you guys know, I've been able to put to rest a couple theories that are floating around on here.

1) The 5th gen 3rd gear is no thicker than the 4th gen 3rd gear. I measured it (my trans is at the shop www.teamrip.com getting built up right now). They are the same thickness, 14.3mm. So unless the 5th gen 3rd gear is made out of some hyper-strong-space-age-ceramic-diamond-carbide-from-Pluto stuff, it ain't any stronger than the 4th gen gear is.

2) The VIN # is on the engine block. So if you have replaced your motor and really want to know what year and model car it came out of, you can find out. It is on a little plaque riveted to the block below the rear bank, driver's side cylinder. Here is a pic (the engine is upside-down because I have it on my engine stand ready to tear apart).

2 Da Max

iTrader: (2)

i heard the 4 th gear is stronger on the 5th gens



jk good find.

Batxel

iTrader: (1)

is there a vin # on the tranny?

Nealoc187

iTrader: (23)

Yes it is on the trans too.

liqidvenom

iTrader: (6)

im not arguing against ur find, which is good by the way, but my 5th gen tranny in every aspect seems better then my 4th gen version. i dont know if its cause my 4th gen one had 90k when it died while my 5th gen one had only 4k on it...i dunno but it just shifts so much smoother and finds gears way better going from 2-3

Nealoc187

iTrader: (23)

I didn't say it wasn't better or smoother shifting. I'm saying the rumor that 3rd gear is stronger in the 5th gen trans is false.

i30ds

iTrader: (8)

Ahhh vidication! Thank God this can finally be put to rest!

Nealoc187

iTrader: (23)

I agree. I always had a very hard time believing that nissan would keep everything else the same, and just randomly put a thicker 3rd gear in there.

i30ds

iTrader: (8)

+1... This feels really good because when I bought a brand new 4th gen vlsd tranny from nissan at wholesale (only $1500), Dave Sz jumped all over my @ss about how I was a fool for buying inferior unit with a "weak" 3rd gear. With out any proof I didnt care.

The thing was manufactured in 2003, so diff. bearings should not be as much of an issue (if any).

BigLou93SE

iTrader: (10)

Where is Dave by the way? Good find on the tranny. How did that rumor start anyways?

Zack342

iTrader: (89)

Like I30ds was telling me the other day i think the situation is most of the 5th gens are newer and have less mileage than the 4th gens so obviously there trannies would be alot better in condition but once they start picking up miles and abuse like all of our 4th gen trans they will start letting go.
Awesome find.
Neal do you have any pic of where the vin is located on the Tranny? I wanna see if there is a vin on my VLSD tranny.

Stephen Max

iTrader: (59)

So, dimensionally it is the same, but it could still be made out of stronger steel, eh?

If you have access to a Brinnell type hardness tester, you could determine if the material is the same or not.

MDeezy

iTrader: (27)

Finally, I have heard the rumor for a while and thought it to be true. Glad it can be put to rest. I too do wonder how the rumor was started, If its stronger it would have to be with the maerials cause its not the size/thickness.

i30ds

iTrader: (8)

So, in my book, there is absolutely no advantage of putting a 5th gen tranny in a 4th gen. In fact you could say one would be at a disadvantage with the whole speedo getting thrown off issue.

i30ds

iTrader: (8)

I dont know what happened to him. I think the mods might have canned him. I cant see his posts anymore, and posts that I know he made in other threads are no longer appearing either.

Id like to know how this stupid rumor got started also.

MDeezy

iTrader: (27)

I thought the speedo issue is cured with a swap from the old trannie ( I know some have had unresolvable issue but I thought on a whole it doesnt happen that often). I also thought the general census was that Nissan caugfht the bearing issue (for the most part) and 5th gens didnt see the bearing issue anywhere near as often as most of us 4th gens did. If this isnt the case then i30ds there would indeed be no advantage to get a 5th gen tranny, maybe worst as they cost more than a 4th gen tranny

Stephen Max

iTrader: (59)

You guys are discounting the rumor based on only one criterion for strength of a mechanical part. What about the other?

Not that I believe the rumor, but I like to believe that Nissan engineers would try to improve the reliability of a part. Of course, it's the bean counters who eventually make the decisions.

Turbo1er

iTrader: (1)

10char

MDeezy

iTrader: (27)

I honnestly would like to believe (with proof) that the 5th gens are better build and more reliable, its a shame to have to go thru as many trannies as we have due to a Engineering error or mis calculation.

i30ds

iTrader: (8)

I dont know, maybe the issue with the speedo did get resolved. The diff bearing thing is still up in the air as far as I am concerned. I have been hearing about how those 5th gen guys are getting the bad bearing **** as well. Only time will tell if it is as bad as the 4th gens.

Nealoc187

iTrader: (23)

What you've said is true, it is possible that the material itself is stronger. I don't have a Brinell-type, Vickers-type, nor Knoll-type hardness tester. So no I don't know the Rockwell of either gear. In one respect this is little more than another half-arsed rumor, since we don't know the numerical strength of it still. However I like to think that since this assumption is based on one quantifiable value rather than PURE speculation, it is more likely to be true. That and the fact that Nissan likely has no REASON to increase the strength of the gears in the transmission. I've never heard of an epidemic of soccer moms and businessmen blowing 3rd gear up on their way to the PTA meeting or business seminar that would warrant Nissan redisgning one part out of a thousand part transmission.

The simplest solution is most often the correct one Occam said. But I know that engineers like to play devil's advocate sometimes so I understand and I agree this is not a definitive, but most likely.

I'll see if maybe I can get up to my old stomping ground (WMU engineering department) and see if perhaps my old materials science professor might like to test a couple gears for me if they haven't started putting the gears back on the shafts yet.

Nealoc187

iTrader: (23)

I don't think it's engineering error or miscalculation at all. Nissan wasn't counting on maniacs like us putting double and triple the power through the parts they designed.

MDeezy

iTrader: (27)

Good Point.

But gone thru one tranny, and currently in need of replacing my current one, and I havent done any mods power wise, not even a y-pipe. I would like to thank you for providing this information, if indeed there is no difference between the 5th gen and 4th gen then I might as well purcahse a 4th gen tranny as they are cheaper. Looking forward to your results.

Kevlo911

iTrader: (36)

I thought it only had better synchros(spell?)

Nealoc187

iTrader: (23)

When you say you've gone through 2 trans what is it exactly that you did to them?

MDeezy

iTrader: (27)

The first tranny was the diff bearing, was leaking oil thru a badly worn input shaft, plus a bearing got loose in there, I could hear it when you spin the input shaft. That tranny was in the car when I first purchaed the car.

Current tranny (2nd one), I'm hearing that same whinning noise that I heard with the first tranny, and in the morning the clutch slips a little bit and I cant come up with the right words to explain, but it feels like a small leak and oil is getting on the clutch. This tranny will come out when I get the proper funds.

I drive normal, never gone to track, never done 1/4 miles, never even did a burn out just normal driving, with the occational higher than normal shift points. Maybe I've been getting the bad ones out there.

Nealoc187

iTrader: (23)

Oh, that doesn't really have anything to do with the strength of the internals though. That is simply a problem with using incorrectly sized shims behind those bearings, resulting in too much preload on them. Nissan makes a million different shim sizes (in like increments of .001 inches or something like that). Each bearing is slightly different in size at the microscopic level, and requires a shim of the proper thickness for the right amount of preload for long bearing life. I assume nissan decided to cut corners and stick the same shim in the transmissions for years, rather than measuring each one (time intensive process = $$$). They probably didn't think it would make a such a difference, or else they knew it would start to show signs well after the car was out of warranty, so they didn't care. I have this 5th gen trans because the owner was selling it due to this exact problem, so either nissan didn't know it was a problem, or didn't bother to correct it. But 5th gen trans are definately not exempt from it.

MaxKlinger

Is there a definitive time when Nissan realized the bearing preload issue and made corrective actions? I've been looking at getting a 4th gen 5-spd for a while and now I'm wondering if it's worth it - I obviously don't want to buy a car that is on borrowed time before tranny failure. While the automatic is boring and slow, it's proven to me to be incredibly solid and reliable, as my original has 210,000 miles on it and still shifts great - and it's had its share of hard driving.

liqidvenom

iTrader: (6)

well i really have no imput on this, my first tranny went without me doubling my power or anything like that. i never seen a track nor any hard launches, my 5thgear just gave out and the next morning coming home it all went gear by gear until it locked up on me. i just feel that there is a difference somewhere in the trannies and i say that due to my feel of how both drive and shift. but thats just my views and u guys can take it for what its worth