Esser

iTrader: (2)

Where did you buy the gears from? I believe the gears from the frontier are different from year to year, and there is only one correct version that will work.

bjr

I got them from Adam at Z1.
The Quaife is 5.035 +/ 0.005" per their engineering drawing for the hub the gear goes on. I didn't bring it in to work to grab a pair of calipers with deep jaws because I knew that my Frontier ring gear measures 5.040" and if I set it down on the quaife on a machined table and an indicator i can move it towards and away from the indicator a total of 0.005" while the quaife remains in place. So indirectly it does measure 5.035 and they would say 5.030 to 5.040 is in tolerance.

ian99rt measured an old 350 original ring gear for me at 5.041"

I was ready to put it back together with shims between the diameters to hold it centered and then pull them back out after everything is tight. I tried this a couple of times yesterday and got 0.0015" axial runout and 0.002" radial. I had 0.006 radial before I paid attention to just how loose this thing fits.

But this morning quaife is wanting me email them to make sure everything matches their drawing. I think it does.

It only makes sense that there should be manufacturing tolerances here and that not every gear/diff combo will be a nice tight slip fit for centering. The question then becomes what is the accepted assembly procedure to get it permanently centered to give you good numbers on runout?? Still don't really know

Maybe when it's all one manufacturer there can be a tight fit? The VLSD I took out of the spare pumpkin I am rebuilding this with, I cannot get any shims slipped between the gear and diff hub. It is tight. I really didn't want to take it apart becuase I don't know if it will sell better as a set or pieces.

I think I know what I will do going forward with the shim method but don't think other people do this. At least the people that measure stuff and know what they are doing! I would still really love some advice before I go through with what I think will work but seems kind of shade tree mechanic.

Esser

iTrader: (2)

It sounds like the parts you are using are fine. I mean 0.005 is a typical tolerance, for an outer diameter. However, the inner diameter of the bearings is more critical. Are you using new bearings or re-using the old ones? The radial movement could potentially be caused by movement inside the bearings, which could lead to a noticeably worn bearing, or just some small play (i don't know how you are measuring the play in the gears unless you are guessing).

I don't know much about the Quaife, but I doubt it uses the same amount of shims as the OE part. More than likely you will have to space it to their specific specs and per their tolerances.

When you take it back apart see if there are any metal shavings in the oil. A small amount will indicate that gear mesh is good. If there are no shavings, then you may need to space them closer together.

bjr

The bearings are brand new and the preload on them is right and the bearing caps are torqued properly. I can prove by centering the gear with shims and measuring then loosening it back up and letting it center wherever it wants to that it is all in the ring to diff hub fitment.
I know I explained a strange way of indirectly measuring the diff hub and being too lazy to take it in to work but I do have plenty of measuring equipment at home and machined surfaces to mount it all on so my findings are exact.
Everything has been cleaned several times and run over with a finishing stone. I guess that I just have to decide if I put it together like everyone else would or try and get it perfectly centered.
Quaife verified that it's just manufacturing tolerances and suggested to get a nice tight, centered fit to add on material to the ID of the ring gear and machine it back off to my particular need. I had thought along those lines before but only came up with welding to get more material to shave back off but that obviously is not the way to go here. I will be investigating any products or methods to do this before I go ahead but do not know what I will find. I have horrible success with JB weld. I don't know if I don't get the surface clean or if the mix is not a perfect 50/50 but I get that stuff to work about 10% of the time.
Thanks for the advice.

ian99rt

iTrader: (12)

I truly think your over thinking this scenario.

#1, your not going to get more material permanently attached to the ID for centering without annealing the heat treated metal, welding, machining, then reheatreating.

#2 An Epoxy solution is not an option, it will not stick and with the vibrations you'll just end up with epoxy chunks getting ground up in the gear lube.

I personally just depended on the criss cross torquing of the ring gear bolts, besides when the ring gears mounted and spinning on the diff, how are you actually measuring what the ring gear rotating concentricity is?

From what i remember theres not a good surface to measure that off of the ring gear (OD is a tapered surface).

If you truly have to know that you've torqued the bolts down with the ring gear perfectly centered: your better off using shim material to get it centered, torque down the bolts, then remove the shims and continue assembly.

Don't forget the red Loctite on the ring gear bolts.

bjr

I'm with you 100%. Especially when you phrase it like this (and we've talked about this before) : "If you truly have to know that you've torqued the bolts down with the ring gear perfectly centered: your better off using shim material to get it centered, torque down the bolts, then remove the shims and continue assembly."

Quaife got me overthinking a little again as they suggested getting more material. And I was going to do a little more research to see if I could learn something about the Engineering world of materials today but I didn't think you could do much with a hardened surface either. But I was willing to look into it.
I'm not looking back anymore. Off to shim and go forward. If the ring gear bolts can hold it in place rotationaly then it can hold it axially. If the rear end was ever shocked so hard it could shift at least I will start out centered for all of my backlash readings and it will move most by 0.002" and I'll still be cool.
Thanks for your support!

Esser

iTrader: (2)

Word.

bjr

I think that if I was going by the coast side (first pic - notice file name) that I would almost be done adjusting. But the drive side is off some and that's the side to pay attention to. I need to take some pinion shim out right? Any idea how much?

http://imageshack.us/photo/my-images/195/coaste.jpg/


http://imageshack.us/photo/my-images/812/drivea.jpg/

I looked at the shim chart overnight and only have 4 shims available thinner than the one I have. Can anybody tell me if I am reading the pattern right though?


I've got one vote from someone at work to run it like that. But he has limited experience.

Anybody??? I'd like to keep working on this and get it done...

bjr

Despite my ramblings about centering the ring gear and a couple of other minor things my gears/quaife went in as well as can be expected. I'm 400 miles into "break in" but the front seal has been leaking since day one. Everything else turned out perfect!
What could I have done wrong? It is very slight weeping but it is starting to slowly grow a stain on the case after a few days.
I've got some votes to redo it and I am bummed out about that. The solid bushings did reveal that I need to do a wheel bearing, so it is not all bad that the pumpkin would come back out where I can see and work on it becuase I will spend the whole day doing two wheel bearings, the axles will come out easy as can be then for doing the bearings and can do an axle click TSB on both sides so it's not all in vain.
But putting the pinion nut on and doing the crush washer was one of the things I nailed easily the first time and it was the thing I was most worried about doing on this project. I know I did it right and I don't want to mess with it at all!

What's the plan to replace the seal?

1. ) I don't have ANY idea what I did wrong. I am hoping that after taking off the flange I can at a minimum tell if it is leaking by the shaft or by the wall of the case. If it is the wall check for scratches in the wall. If it is the shaft, I only used the grease that came on the seal. What other methods are there to coat the seal and or splines with to get a good seal? I have no experience with this. Need some advice bad.

2. ) I need a plan to get the preload just right again. My thoughts are to take a preload reading on the bench now that it is broken in. Replace the seal then put a new pinion nut on and try to get to the same preload then add 1-2in*lb more to make sure the crush washer is still spacing everything properly. Will this work or is the only acceptable practice to tear the whole thing apart again and get a new crush washer? I did not order one at this time, only everything else I need. What am I risking by doing this?

Anyway, I could go on. What would you guys do about the leak keeping in mind I want to do it with acceptable methods.

Also, I remember the side seals going in great and it was real obvious where they stopped. I remember driving the front seal in and wasn't sure after awhile where to stop, where it would stop, etc. Don't remember exact details but it could be a clue....

harman850t5

iTrader: (8)

The front seal goes in almost 3/16 of an inch. It should hit a backing plate. Hopefully you got it squared away by now

Just got mine put in last night. Haven't really ripped on it yet, not sure if these require heat cycling or not. Still, with a now quiet Nismo, except for low speed turns, and 4.08s I think I giggled like a school girl a couple times.

A couple months back I took my diff out to find a bad carrier bearing and inner pinion bearing, so decided if I had to go through the trouble of pulling the pinion the 3.5s weren't going back in. Took me and a friend about three hours to assemble. Somehow the original shims put this set up perfect too.

bjr

If you go by the books, you have to break in your gears. The first drive should have been about 5-10 miles in town then let it cool down for at least an hour before you drive it again. The theory is that if you did everything right that when the gears are meshing for the first time they definatley will wear a pattern into each other and remove some material. If you don't take it easy the first two times you drive it and hit it hard or go 55mph+ for a long time the break in could cause excessive heat and break down your oil and damage the top coating of the gears exposing a much softer layer of the gear face leading to extremely short life. It doesn't sound like you have done this to me but only you will know. There is plenty advice about break in out there if you Google it. It is also one of those things that people that don't understand it have wide opinions on like choosing the right kind of motor oil, etc. Some will say there is no break in. Just continue to take it easy and drain all of the break in particles out after 500-1000 miles then rip on it.

Turns out my stupid seal question was a trick question. It goes in as far as it will go becuase of the front lip on it. Actually I guess the side seals are the ones that you could choose to drive in flush or go farther than that not knowing where to stop.

Anyway, yes I did have a chance to redo it by now and have been quiet so as not to jinks myself. I damaged the bore the seal goes into removing the old one and never noticed. I fixed it and put a new one in and I have been leak free for over a week.

I am just the opposite on my feelings with my mods. The 4.083 gears are great but not that impressive to me. It sure does wake up the power band but doesn't necessarily feel much quicker. Certainly not the tire shredder in 1st and 2nd that everyone is so crazy about. What was much more surprising to me and puts a big grin on my face is going from OEM open diff to Quaife. Even at a medium speed turn it is amazing how much better it corners. The front wheels tuck in tight and the car goes where you want it to always. I never knew how much an open diff caused the front end to push. And nothing brings a bigger juvenile grin than a quick 90 degree turn from a dead stop. So much fun to have the whole rear end just jump to the side with a little counter steer to keep it line than one tire spinning and wondering when you are going to gain speed again. The most eye opening test is to put one side of the car in the gravel and the other side on clean road and floor it. The car just accellerates hard with no wasted tire spinning or drama. So nice! It is a great upgrade. I believe the Quiafe web site now that it just gives you more traction in any situation. I hate winter but am excited to see how much difference I will experience when the snow and ice fly.

harman850t5

iTrader: (8)

Yea I read up a bunch on different sites. I did it right so far. It's been tough not to rip into it. Just have 250mi to go. So far I think it's having my Nismo back, after having to go open for a few months again, that's making me grin. Even had a guy yell at me to stop because he thought my rear was about to blow in a parking lot. But I'll see if the gears live up to my expectations later this week.

Glad you got your issues worked out and can enjoy it now.

silverstone03

This is getting at the question I have had while reading this thread. I have an '03 DE and I've heard the power drops off after around 6500 rpm. Many say that in order to take full advantage of the 4.08 final drive, one must raise the limiter to 7200 rpm. However, if I'm constantly losing power after 6500 rpm, how would this help?

jv350z

iTrader: (6)

I joined the club (4.08 bought from the marketplace). Feels great, but my MPGs have gone to $%^&*...maybe it's because I'm just too throttle-happy these days. Not sure if I need to re-tune for this mod.

musubi

iTrader: (1)

No re-tune needed
Looking at this as my next mod.

bmyles

Diff is at the shop getting the gears swapped. Pretty excited for the results (and the side effect of shredding more tire). Hopefully have it back Fri/Sat. I'm not concerned with fuel economy since I'm only averaging 7k miles a year right now.

bmyles

Everything is buttoned back up! Went for a quick test drive around the block and just cruising around up to 35mph, I can already see how short the gears are. Can be in 5th without lugging the engine. Next up will be having some fun and maybe a video as well.

kyle22

iTrader: (4)

Thinking about doing this mod next, my application is both worlds of drag racing and auto-x, see a lot of HR guys have 4.08s but have heard for both applications 3.9s work best. looking for more information on this and what would be best suited for my needs.

BigBlue

iTrader: (4)

I haven't driven or rode in a Z with 4.08's, they sound very nice! I have the central 20 3.9's and totally love them in my '07. You would too; my engine wraps higher; 80 mph is now about 200 rpms higher, but you really notice it when you stomp on it! Things to consider: 4.08s are "far" easier to find/buy, cheaper price because they are also in America for other Nissan vehicles (trucks). My 3.9s cost more and had to be shipped from Japan to AZ. to Vivid Racing, so it could take longer for you, cost more, but I think that you will make the right choice with 'em! PM me if you have any questions, etc.

andre12031948

I, like the poster before me, bought the same gears from the same place Just recently I put a 4:08 whole housing in, just to drag race. My 3:90 gears were set up by an expert. I WILL put that 3:90 housing back when I'm done with drag racing. The 3:90's are best for all type of driving.