RyanTaylorClark

iTrader: (1)

So, my tranny has been making that horrible grinding noise for almost a year now caused by the spalling on the bearings that so many of us have had to deal with. I really didn't want to drive on it for this long, but I also didn't want to pay someone 2G to do something that I know I can do myself. So, I had to wait until summer when I had time and after I moved so I would have a garage. I got the tranny out just fine and dissasembled fine, but now I have a few questions. First of all, of the many bearings on the input shaft, main shaft, and differential, only one seems to have spalling (which I might add, is <b><u>really</u></b> bad). Should I just replace the bad one on the differential, or should I redo all of them to make sure they are not all excessively preloaded? Also, quite a few gears in there seem to have grooves running all the way around them. I also saw them on motorvate.ca's pics. Are these normal? They don't look healthy, but they could serve a purpose. Thirdly, is there any particular type of degreaser I should use to clean the halves of the transmission and the parts inside, or will an engine degreaser work just fine? And lastly, does anyone have any really good pics of how exactly to measure the bearing preload? I really want to make sure I don't put the wrong size shims in there and have to do this again. I appreciate any help any of you can give me. Sorry this is so long. I know how much it sucks to read <b>super</b> long posts. I will take pics of the spalling and post them in a day or two. Oh yeah, by the way .... my car is a 1996 with ~120,000 mi on it. I am guessing the spalling has been present, but not noticable since my parents bought the car at ~55,000, since this is about when most people begin to have problems with this. Thanks again!

RyanTaylorClark

iTrader: (1)

Of all the 4th gen maxima owners who have had problems with their trannies, noone has any advise for me?

RyanTaylorClark

iTrader: (1)

Man, I can't believe noone here can give me any advice about this!

jkslaughter@hot

I've not done this on a Maxima , but very detailed instructions including tolerances are included in the factory service manual.

JamesNH

iTrader: (12)

what im doing is going and replacing the differential and input bearings. I just dont know where that grinding sound is the front or rear input shaft bearing.

Since your in the transmission how hard was it to get at the input shaft bearings?

I dont know if you have fsm but i would dl one or buy one.

Just for information there are two gear assemblies and one has the input shaft bearings on each end making it so there are only two input shaft bearings correct? And with the other assembly with the main gears thats the mainshaft with only two mainshaft bearings in the whole transmission correct?

Sorry to hijack.

maxger

I replaced my both Differential bearings and one of my input shaft bearings 3 yrs ago at 60,000miles on the car.

Right now I am have the same problem with my transmission again @ 135,000 miles. It is apart in my garage right now. I thought I had inproperly shimmed my differential but under close examination I found my diff. bearings & original main shaft bearings were in excellent condition. The other input shaft bearing I did not replace was in bad shape.

So if you see any spalling or any vibration (ticking) when you spin the input shaft bearings replace them. And replace them as a set. My bearing right now spins as smooth as a rusted shopping cart wheel.

Don't worry about the groves.

Use GL4 oil.

Motovate sight should give you enough info on the prelload measurement as long as you have the gear to measure it.

Take an hour and check your clutch and if it has any wear, replace it.

Also you can clean your egr valve. It is easy to get. Fuel filter is an easy replace.

Hope this helps

G

MDeezy

iTrader: (27)

How was the install, its one thing to read a write up but another one to get actual feed back from a person who has actually done it. If its not that hard, I could save a lot doing it to my tranny instead of buying a 5th gen.

JamesNH

iTrader: (12)

I dont want to make another thread and i feel it would be useful to this one, But how do you know if the mainshaft bearings need replacement before opening up the tranny?

maxger

Really the only way to check th bearings is to take the tranny apart. But even taking the cover off the tranmission is still not good enough. The first time I had the problems with it I took it to a transmission spot. They opened ther cover and check the bearings. They looked fine. I put the transmission back in and still drove like crap. I decide to do it myself . Took the differential, main & input shaft out and found the differential bearing and the input shaft bearing was shot on the other side. The transimission guys did not loook any further . Waste a lot of time and money.

I may be wrong but I have not heard of anyone have a problem with the "mainshaft bearings" I have only heard of people have problems initially with the diff. bearings (torque) and the input shaft bearing (high rpm).

Signs of bearing failure. Diff - Leaky axle seal with a little axle place . Input shaft - a clicking noise that follows the speed of the engine (rpm) and not the speed of the car. Clicking stops when you push in the clutch. Main shaft bearings -?? There must be a few other signs that I missed also.

maxger

[If its not that hard, I could save a lot doing it to my tranny instead of buying a 5th gen.]
I was thinking about buying a used transmission because I did not want to go through the same situation again. Decided to check it & was lucky it was only one bearing ($35.00). You have to have the gear, the time and patiance. Buying a good used tranny and put it in yourself is a good option. But the main thing is if you do the work yourself it will be done right
Hope that helps

G

MaxGordon7

iTrader: (36)

ya its not hard really, just first time you need that push to make you do it. Think about it most mechanics(im not saying all) really have half a brain and the main guy you talk that does have a brain doesnt do any of the work. Then you get charged 90 an hour for expert mechanic prices. If you can take stuff apart and remeber how to get it back together its easy also i just took out my auto trans for the first time, not too bad. I have a link to the FSM nissan guide but its not working right now, just pick up a hynas manual that is what i used. the manuals doesnt seem to go in order cuz it will tell you to take out bolts but you need other things to come out first, it has all the main stuff.

dgeesaman

iTrader: (10)

Resurrecting this...

I'm suspect of my diff carrier bearings. Can't complain though since it's been good for 140k so far. I get a little leaking and a little clunking, and my highway fuel economy is down 5mpg from what it used to be. I've got one M/T rebuild under my belt, just not this car.

1) Did you buy the carrier bearing shims? I'd rather not put it all together, then wait several days just b/c I couldn't figure out what szie thrust plate to buy. Does anyone other than Nissan stock them?

2) How much extra trouble is it to take out the mainshaft and input shaft bearings? It seems like a complete gasket/bearing kit is the smart way to go.

Dave

dgeesaman

iTrader: (10)

And another question, now that I've been reading the FSM is detail...
3) I see some fancy tools to measure preload on the mainshaft and input shaft also. I have a mag-base dial indicator and feeler gauge. Will this be enough? Must the bearings be pulled to change/adjust the shims?

4) How hard is it to pull the bearings? I have a set of basic 2-jaw pullers. Would it make more sense to pull the tranny apart and carry the parts to a tranny shop and have them pull all the bearings at once?

Thanks again. If I can borrow a cheap digital camera, I'll do a writeup like I did for my RX-7 transmission rebuild (which I have at www.davidgeesaman.com)

Dave

dgeesaman

iTrader: (10)

Bump - I checked the axles tonight and I have noticeable play and minor leakage on the driver's side. The pass side probably does too, except it's locked in place by the bearing housing under the PSP.

One other thing I noticed - while trying to roll the car forward (in neutral, e-brake off, on flat pavement), there was much more resistance than in my RX-7. Makes me wonder if a good tranny rebuild will surely fix my fuel mileage problem.

Dave

ThurzNite

iTrader: (13)

I just had my tranny shimmed, seals and bearings replaced. On top of that, where the input shaft enters the case/bell, the case is cracked. Really strange. It explains the nasty vibrations I got. Other than that, no more drivetrain slack, smooth clutch engagement (I didn't touch the ACT I already had). Oh yeah, some superficial coating on the inside and outside of the case (not the bell part) was flaking off. They had to sand it down and coat it with some kinda bronze paint. Anyways, 165k miles here.

BTW, I took out the tranny and brought it to www.aagearsandshafts.com. Javier worked on my tranny. Total was $450 cash, 3day turnaround, 6month warranty. They only work on standard transmissions. My bro also had them check his 2k tranny, and he's satisfied with their work too.

Jae

JamesNH

iTrader: (12)

dgeesaman i just resently rebuild my tranny about 2 weeks ago. What i did is took the top input bearing off cause i could with a pulley puller. I then did the jay25 way of pulling the differential. I tried to take the bearings off with a dremel but ened up screwing up the speedometer gear. So what i did is pay a engine builder 50$ to take the bearings off and press them on. After i measured the play i went to nissan and order the shims. I got next day shipping it was only 3 dollars and the parts where 3 each.

THe one thing i stress i add extra time and make sure your tranny shifts fine before you reassemble.

I didnt take the other bearings off becuase i inspected them and they seem fine Plus i didnt have the tools to remove the parts that hold the rear idler and main shaft in place.

If you want the rear input shaft bearing i have one currently for sale.

-James

dgeesaman

iTrader: (10)

Thanks for the response.

What would that method be? As I understand it, you can simply open the case, life the input and mainshafts, and slide out the diff as a unit.

That's what I'm thinking of doing - is it easy enough to take the shafts out as a unit with the bearings on them and give them to the shop? Will I need a press to install/remove them from the tranny case when shimming? Did you have trouble with the preload measurements?

Thanks,

Dave

JamesNH

iTrader: (12)

Yeh you can pull on the shafts and then pull the diff out. THe one stupid thing i did was try and remove it with the speedometer sensor still in the tranny.

I didnt remove the shafts i would buy the bearings and just replace the ones that look bad when you get in there. I havent heard of any main shaft bearings going so i would buy the diff and input if you suspect the input bearings. If not just buy the diff and make you life easier. I brought it to a shop because it took the guy a couple hours to get me my diff back and it was around lunch time. WHere it took me a coupole of hours to find out and give up. When shimming the diff all you need is a punch to remove the outer race from the tranny so you can measure and remove them.

I would get a fsm. If you wondering the order of the bearings it goes shims>outer race>bearings>diff<bearings<outer race

You can pm with questions or im me the if im on.

-James

dgeesaman

iTrader: (10)

I'm getting a bearing kit from GT Transmission for $178. I figure if they're reasonably removable, I'd be silly to not replace them. I'll probably see how far I can get it all apart, and take that to a tranny rebuilder to have them to the pulling/pressing in one shot.

I have an FSM, and it looks fairly complete. However, I know from doing the 5speed in my RX-7, that some bearings are much easier to pull than others, and that they show lots of special pullers in the FSM that make it difficult to tell what can be done with a punch, slide puller, or 2-jaw puller.

There's a local guy with a couple of these trannies - I'm going to try and rebuild one of his cores first, then swap with my car. That way I can take my time and work with enough space. (damn 1-car garage!)

Dave

JamesNH

iTrader: (12)

I think the diff and main need a slide puller and the input can be done with the 2 jaw puller.

Good Luck You going to get sick of a garage that smells like tranny fluid.

-JAmes

Sin

I did mine this last summer. I changed every synchro, both input shaft bearings, both main shaft bearings, both diff bearings, and all the shims required to set everything back into specifications.

Some essentials. A shop press. Sure, you could try beating things on and off . . . right. Multiple 3-jaw pullers of various sizes, a 4", 6" and 8-10" should do the entire tranny. You may get away with one or two depending on the design of the puller. Lots of brake cleaner (I'm talking a case of 12). Lots of Varsol, about 1 gallon. Lots of high quality multipurpose spray grease (I used AMSOIL for example). High quality RTV (I used Loctite). A high quality gasket material (I used Permatex). Lots of brushes for cleaning. Lots of nitrile gloves for cleaning and reassembly. A quality dial guage, and caliper, I find most Mitutoyo calipers and dial guages very accuratey. And you'll need some way to secure the dial gauge to take various pre-load measurements. I used misc bolts and spare metal I had lying around, and welded up a jig to hold my dial gauge so that I could take various preload measurements. I couldn't think of another way to secure it for the measurement. Magnetic base clamps don't work with aluminum tranny housings. Short of welding a jig, I don't know how others did it. A high quality paste grease for reassembly, again AMSOIL. LOTS OF SHOP TOWELS. Lots of plastic bags to hold the various tranny components. C-clamps. Lots of gear oil for flushing.

Basically, follow the FSM as best as you can, and use common sense. So far, I've seen the US 98 Maxima FSM and the CDN 98 Maxima FSM, and if you follow both by the letter, you will not install 4th gear back at all. It just skips over it somehow. So stick to the book, don't assume things are ok unless you know for sure, and use your brain at all times, and you'll be fine.

The FSM has EVERY little bit of info to figure it out. Just make sure you take EVERY SINGLE MEASUREMENT THAT THE FSM SPECIFIES. Not doing so means you'll be needing a rebuild again.

Also, as a general note, fix your trannies asap, when they need it. I had a buddy also with a 98 SE 5 spd, and he drove his car for almost a year on noisy crunchy diff bearings. His gears looked WAY more beat than mine did when I took my tranny apart, and it was definetly a result of bearing chunks wrecking the rest of the tranny. To this day, he has a lingering problem. Due to peripheral damage as a result of the gear bits floating through the metal, if he shifts into R and the car is TOTALLY stopped, his tranny puts the car into 2nd and R simultaneously, stalling the engine on spot if he comes off the clutch. After that he only has 2nd gear and nothing else. He has to limp the car home in 2nd, then he must then remove the reverse sensor, drain the oil, use a long screwdriver and a hammer, and top the 2nd gear coupler loose, and fill up the tranny again. We've checked every tollerance we can on that tranny, we're 99.99999% certain it is a result of excessive play as a result of the bearing chunks floating around so long.

As for what you should and shouldn't replace. Well, the first time I took my tranny off it took me about 2 hours. By the time I finished my tranny rebuild, I had a removal down to 40 minutes. So getting the tranny off the car and opened up isn't a big deal.

However, ordering parts is a HUGE ordeal. Bearings are typically $30-70 CDN, and most are towards the $30-50 range. At that price, you might as well change them all. Especially the input shaft ones because removing them damages them. And the main shaft bearings are only $40-50 each. The diff bearings are a bit more, but those are the ones you're replacing anyways. As for the synchros. Man, I wouldn't have it anyother way. My tranny isn't S2000 smooth or anything, but with new synchros, HOLY JEEBUZ! So if I were you, I'd atleast buy both input bearings, both main shaft bearings, both diff bearings, and every synchro, except maybe R. I replaced it, but it's not that big of a deal. I'd definetly recommended replacing all forward gear synchros.

When you get all your parts in, plan it out like this. Day 1, remove from car, tear down. Install all new components. Reassemble tranny, take all measurements required. Yes you will have to reassemble the tranny to take some of the preload/freeplay measurements. Day 2, order the new shims/spacers you will need. Hopefully, they arrive next day. They can take WAY longer as well. You will also probably have to buy slightly larger ones than you'll need as Nissan doesn't make any thin enough to put the diff within specifications for freeplay/preload. You can try acid etching with muriatic acid, or by machining the shim. I suggest machining, but that takes some skill, or a machine shop. Acid etching works great for removing .001-003". Any more than that and machining is the way to go. So hopefully, you can get your shims in by Day 3. Reassemble on Day 3. But because the gasket maker for the tranny housing takes 24 hours to cure, You reinstall on Day 4. Do not use the quick curing RTV's and silicones. Sure they cure faster, but they also leach silicone into your tranny fluid over time. Also, they tend to have a higher build, so because of this, it will actually throw ALL your tolerances off on the shimming of the shafts and the diff. Remember, we're dealing with .001" here. The thickness of the sealing goo matters.

That's what I can think of off the top of my head.

maxger

Sin pretty much nailed it . The stink the brake cleaner . It is a good idea to wear gloves.

When I removed my input shaft bearings and diff. bearings I took it to a tranny shop to pull them because the diff bearings are not easy to put off especially with a limited slip differential we have here in canada, The second time I used a bearing puller to take off my input shaft bearing.

I used the FSM & this link.
www.motorvate.ca/mvp.php/807

I had to wait for bearings. Then wait for shims. So it took me a 1.5 weeks.
My differential was off by 8 shim sizes. I never heard of anyone with a main shaft bearing problem. I looked at mine closely and they look fine. I think to check the main shaft bearing for sizing shims is quite a difficult process compared to shimming the difff. bearing

Sin did you check you main shaft bearings for shim sizing? I wish I would of known about that gasket maker . ( used silicon) O well it still does not leak works fine.

Anyway good luck

G

Sin

Yup, basically, I followed the FSM, and anywhere I needed to have a "special service tool" to hold my dial guage in a particular way, I just used metal stock, and a welder to make what I needed. That's why I mentioned that I can't imagine how other people took some of their measurements, without metal stock and a welder. Without fabricating your own jigs, and what not, unless you use the special service tool from Nissan, there is absolutely no way in hell you can be sure things are in spec. If you can't, what's the point in even doing the job in the first place? That's right, there isn't.

The glove recommendation also goes towards keeping everything clean. It's a lot easier for you to wipe off nitrile gloves, or to simply change them than it is to clean your hands during reassembly, when cleanliness is highly important.

I cut my differential bearings off since I was replacing them anyways. Way faster, way easier, just requires a very skilled hand, and experience cutting inner bearing races away.

Using silicone won't cause leaks. If anything it seals better than typical anaerobic gasket maker. However, it has a MUCH higher build, which WILL DEFINETLY throw ANY of the main shaft, input shaft, and diff free play measurements off. When you take the measurements, I'm assuming you do so without the gasket maker. Thus when you do put it in, if you use a high build one, that doesn't compress as easily as the anaerobic, it will basically increase the free play by a solid .005 or maybe even more. And for anyone that's ever looked at the specifications, that's quite a bit. Definetly enough to throw either shaft, and the diff free play out of spec.

hitman4

Wow. Good job Sin. I replaced my throw-out bearing and reverse gear fork 2 years ago. All I can say is.....just remember what came from where.....and there are no spare parts. Everything else is cake.

dgeesaman

iTrader: (10)

Sin, Maxger, and James, your comments have been immensely helpful. Thank you.

I looked at that mainshaft measurement process in detail. This is what I can tell:
- Since the mainshaft is fully contained within the case, there is no way to directly measure the endplay when the case is bolted together. To handle this, Nissan has an SST with plungers and cylinders and a bridge (all precision machined and ground to high tolerances) that match the length of the mainshaft assembly exactly, so you can pre-measure the play instead. You made a tool that replicates this somehow.
- I'm thinking of two alternate solutions:
1) Put some Plastigauge at one end and use that to determine the endplay
(credit: ericdwong)
2) Drill a 5/32" hole in the housing at each end. Use one to push the shaft back/forth, and measure the play through the other hole. Tap each hole to M6 and install a screw sealed with gasket sealer. I'll have to make a call on this one depending on how thick the housing is.

Comments please.

While I might have trouble getting my endplay exactly within the Nissan Specs, just getting to within one shim size may well be a major improvement.

I've got a tube of the standard gasket maker. However, to be sure, I'll find a surface on the bolted flange where I can get a consistent thickness measurement, and verify that both before/after assembly to ensure it doesn't build up.

Dave

Sin

I had 1/2" stainless plate that I used to fabricate the meat of the mainshaft bearing free play jig. Using a Mitutoyo dial gauge, variance from high spot to low spot does not exceed .0005". I used a Miller Spectrum 375 Plasma Cutter to cut the 1/2" stainless plate. BTW, I only used stainless over mild because I had stainless lying around, it was sufficiently rigid, and sufficiently flat, as was confirmed by the use of a Mitotoyo dial guage accurate to .0005".

I then used a Miller Millermatic 210 MIG Welder to weld metal stock to make an adjustable jig for the dial gauge. I used a Mitutoyo caliper to check for tolerancing for the dial gauge jig. I can guaruntee a variation of no more than .0005", on my measurements with the setup I had, and again, I was limited by my caliper's accuracy in taking measurements, and no other reason.

As for your other theories, hey man, if you can guaruntee a certain amount of accuracy, whatever works, works. It just so happens that I have my own mig/tig/plasma and a few other toys. So fabricating the "special service tools" is what I tend to do when I need one.

dgeesaman

iTrader: (10)

I'll let you know how it all comes out. I wish I had a welder and machine tools and stuff, but I don't even have a bench vise in my garage. So if it can't be done with hand tools, I have to find an automotive machine shop and pay them. I had an SST made when doing my Mazda, and it ended up costing about $85 (nearly what the real SST costs!).

Fortunately I have a good Starett depth micrometer, dial caliper, no-name dial indicator, and mitutoyo 1" micrometer. Without decent measuring tools, you're right - this is an exercise in futility.

Dave

Sin

I wouldn't suggest attempting a transmission rebuild without a shop press, a MIG welder and the rest of the stuff I mentioned. It's not so much luxuries, but rather necessities to do the job properly. It sounds like you've got most of what is required. But I can't imagine how I would have done my tranny rebuild without a welder.

BTW, I picked up a 12 ton shop press for about $130 CDN. So if you don't already have one, what are you waiting for? SUCH a CRITICAL tool for a DIY auto enthusiast. As for the measuring devices, it sounds liek you can get away with what you already have. I guess your lack of a welder is your biggest problem right now.

dgeesaman

iTrader: (10)

Like I said before, I'm taking them to a shop for all the press work, and I'm not planning to change any synchros. If I really need a press for getting the outer races in/out of the housings, I can take it all down to a friends garage where he has a press.

Unfortunately, I have no space to store a press, otherwise I'd already have one.

Dave

Pudis

I've been meaning to replace the bearings in a transmission I have for some time now, but I havnt got around to it because of the damn special service tool you need for the mainshaft bearings. I have access to a welder and possibly even some machine tools if needed, but I'm having a bit of trouble trying to understand how you made the special tool. If you could give me some detailed instructions of what you did I would greatly appreciate it. Thanks a lot.

Sin

The longer you wait, the longer the chunks of bearings float around, the longer these chunks have to take other chunks out of other parts in your transmission.

As for the special service tool. Go check out the FSM. Please don't take this as an insult, but rather a warning. It's not so much that I don't want to help out, as obviously I'm trying to. But, for me, it makes sense that if you cannot figure out how to wrig up a jig to take the measurements you need, you probably shouldn't be attempting to do this on your own, even with instructions on how to fabricate the jig.

It'd be even worse to go through all the trouble, time, effort, and expense, to do even more damage to your transmission.