NX1600 Transmission or clutch problems?? noise?? help!!

5019 Views 34 Replies 5 Participants Last post by triplefour, Sep 3, 2008

triplefour

Discussion Starter · Apr 11, 2008

my car: 1991 Nissan NX 1600 Manual Trans.

ive got a weird cyclical rubbing noise coming from my front end whenever i am in gear that slowly winds down if i coast in neutral to a stop.
if im stopped completely and rev the engine, it sounds fine.
i put it up on jackstands and tested it up to 4th gear which sounds the worst but i still cant tell for sure where the sound is coming from...

is it the pressure plate? because it only spins when enganged, then slows down when put back into neutral?
the weird thing about that theory is that i would think the noise would eventually stop if i coasted long enough, but as long as ive been in gear, and i havent completely stopped yet, i can hear this noise......it seems like once the noise starts it slows down at the rate of speed that the tires slow down at...

i took off the driver side tire when it was on the stands and it didnt have any effect on the noise. i tugged on both my cv axles and they seem like theyre in there good....do i have to take everything apart to be sure the axles are in there good??

so im thinking its transmission or clutch plate but how do i tell?

also i should mention i just swapped the transmission a couple months ago and everthing ran fine for all this time.... after it started making this noise i checked the gear oil and i was down half a bottle so there is a slow leak but i dont feel like that should cause transmission failure...but maybe it was enough....

well is there any way to tell what it is without taking the transmission off again???

21 - 35 of 35 Posts

IanH

· #21 · May 15, 2008 (Edited)

No, it looks like a few others have looked at your pictures. Are you sure the pieces of metal are not rollers from a roller bearing dis-integrating.
I have dis-assembled many gear boxes but all RWD, jaguar, Vauxhall, Triumph and have been told the FWD boxes are easier to dis-assemble and re-assemble.
I did take my Subaru legacy apart to confirm what broke then threw the lot away and installed a wrecker yard box, final drive gear was damaged, broken teeth. the parts were more than a lower mileage replacement.
Dont be put off by all the special tools and clearances. you can work through that.
When i get 30 minutes I will read the FSM. I downloaded the 94 Sentra one, do you have a 5 speed ?

triplefour

Discussion Starter · #22 · May 15, 2008

um..i used the
Nissan B13 and N14 Service Vol 2 - 100NX NX1600 NX2000 Sunny Sentra GA16DE SR20DE SR20DET.pdf
let me see if i can find the link that was on this forum...

<a href=http://www.icostarica.net/download/Nissan%20B13%20and%20N14%20Service%20Vol%201%20-%20100NX%20NX1600%20NX2000%20Sunny%20Sentra%20GA16DE%20SR20DE%20SR20DET.zip target=_blank>volume1</a>

<a href=http://www.icostarica.net/download/Nissan%20B13%20and%20N14%20Service%20Vol%202%20-%20100NX%20NX1600%20NX2000%20Sunny%20Sentra%20GA16DE%20SR20DE%20SR20DET.zip target=_blank>volume2</a>

and yeah it IS a roller from a roller bearing...the housing of the bearing is completely disintegrated except for that one `rounded` peice i was talking about thinking it was a ring... all the gears and teeth look good. but the main problem with this trans was that it was stuck in 3rd gear. i still cant move the shifter part so its totally stuck. its under all the gears so i guess i have to take the whole thing apart to get at it..

thanks for the help

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triplefour

Discussion Starter · #23 · May 19, 2008

still stuk...cant figure out which roller bearing came off...

IanH

· #24 · May 19, 2008

I know there is not much traffic here but I am surprised no one who has done this has chimed in.
How big is the ring you have ?
My guess from the previous discussion is that its from the final drive, the bearings in the Gear box area are normally smaller needle bearings.
Sorry still haven't had a chance to read up on this.

triplefour

Discussion Starter · #25 · May 19, 2008

well i took all the gears out last nite.....only 6 bolts and it all comes out...
its the hypoid gear bearing on the bottom...on the case side (underneath everything)
it looks like i can pop the shredded bearing off and pop a new one on and maybe sand the area of the case where it went in that got a little shredded as well.
im going to take pictures of everything later today...

triplefour

Discussion Starter · #26 · May 21, 2008 (Edited)

ok i got new pictures up of the gears and all the damage

Manual Transmission Job
(theyre on the second page of the gallery)

IanH

· #27 · May 21, 2008

Ok. Yes the forks are the selector forks, check that none of them are bent.
I suggest you check your other transmission to see what is wrong with it as well. You may be better off fixing a shifting/ selector fork or interlock problem and using an un-damaged main shaft'case and gear asembley
Yes the case should have an outer race pressed into it.
No its not ok for the inner bearing surface to be damaged and torn up.
I think you should consider why this failed like this, it is not typical for these heavy duty roller bearings to fail.
if you decide to use the case and shaft from the other gearbox and swap over the selector fork and interlock and rod assembley i think that would be the best and lowest cost way to go.
I think I have the two transmission problems straight ??

IanH

· #28 · May 21, 2008

Also consider the tapered roller bearing have preload, and the gears and case should be kept together or you have to adjust the preload. So if you sand anything the preload changes. Also sanding the bearing suface will not give you a long life. did I say this already !!!
The color may be due to someone using the wrong oil, hypoid GL5 instead of GL4.

triplefour

Discussion Starter · #29 · May 22, 2008 (Edited)

hey thanks man, sounds like u know what youre talking about AND actually looked at the pictures and read what i had to say.
you got the transmission problems right.
about the sanding... i was planning on removing the damaged "outer race" and sanding the case down then pressing a new "outer race" into it, then taking the hypoid bearing off the shaft and pressing a new one on...
thats what u thought i was talking about right? u didnt think i was going to sand the [hypoid] "bearing surface" did you?
anyway yeah the `second trans` might have had different gear oil in it cause the guy that used to own it was racing it and tweaking it so he probly changed the oil at some point. that would change the whole color of the gears, forks, everything?? thats weird.
i thought maybe they just came from different factories...

as for taking apart the `original trans` im kinda scared and want to leave it alone as a reference until i can pull apart and put back together the `second trans` with my eyes closed...

and ALSO the `original trans` has the same roller bearings floating around (i thought i mentioned that in the pictures that they BOTH have a blown hypoid bearing as far as i can tell)
what i cant tell is how badly scratched the case (outer race) stuff in the `original trans` is... maybe if its ok then on that one i only have to change the bearing, and the shifting stuff... but changing the shifting stuff seems complicated

either way this nightmare is about halfway in...

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IanH

· #30 · May 22, 2008 (Edited)

I think I already mentioned I have not worked on one of these transmissions, but others so I can only help you so far as general issues.

I don't understand why both of these failed the same. unless there is a specific problem related to this generation. the later B14s dont seem to do this from my observations on the forums.

Yes remove the outer race from the case, and do not sand the part where the outer race goes. yes remove any burring over the outer race area towards the shaft but i suggest you do that first.

Press in a new outer race. Since this may be difficult, it may find it help to heat the case and cool the race. It should be a tight interference fit, make sure it goes back at the same depth, it should be bottomed out against a land.

I could not see if the inner race was present or the bearing ran on the shaft. So yes I was concerned that you were going to attack the shaft.

If everything looks ok, read up on the clearances for this shaft and reassemble just this shaft in the case and check it. usually you just use feeler gauges.

If there is nothing else wrong you can re-assemble. You might consider replacing the synco cones and maybe the synco springs if you have any slow synco, third and second maybe.

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triplefour

Discussion Starter · #31 · May 24, 2008

thank you

im going to work on it later...but what are `clearances` ?

IanH

· #32 · May 25, 2008 (Edited)

Clearance means the distance between mechanical parts.
I.e. in this gearbox the between rotating parts in thousands of an inch.
A real gap is positive and a clearance, a pre-load is negative and clamps the parts together. I note that they just give a pre-load with no negative in the tables.
I don’t know which transmission is yours so I just read the first one.
Ok in Vol 2, MT -14 shows the main shaft, part numbers 30 and 31 provide the clearance adjustment or preload.
MT-22 shows checking the gear clearances on the main shaft. Useless you feel you must do this, I would leave this, and it will be close, till the second gearbox when you have the car running. It also shows a press to remove the main shaft bearings.

I think you can check the synro wear clearance with the shaft assembled, they do it when the main shaft is dismantled, if in spec and you have no complaints, leave them. MT-24

MT-26 and MT-27 press on main bearings.

MT-31 press in outer race front mainshaft bearing

Adjust mainshaft main bearing pre-load MT-33 shim table MT-102 p161
Note the main bearing cover enables you to change the adjustment shim from outside.
The next type of transmission has a shim on the shaft between the bearing and the shaft land. MT-55

About all the pressing and pulling. I have used three leg pullers on things like this, if you can get a bearing puller holder like as shown in the manual and use a puller on that it would be better.
To re-assemble you can use a hammer, use blocks and things like sockets to position and drive things in and on.
Be careful not to chip anything, I chipped a Jaguar mainshaft once.
If in doubt it would be better to take in to a machine shop or auto shop and have them do the pressing and pulling. Here in Dallas things like this were about $6-10 a piece. No idea on prices these days.
Take everything at one time, saves set up time. ie get your new bearings first.

(Replace the oil seals.)

(get part number of bearing and go to a bearing supply house. On ball race types the last letter often means clearance, you can use tighter clearance bearings. Automotive often uses "c" clearance bearings loose fit ball bearings.)

Good Luck......

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triplefour

Discussion Starter · #33 · Jun 21, 2008

well the cars still sitting in my garage...i figured out the part i need to replace in the transmission is called the `mainshaft front bearing`
nissan part number 32219-62y00 and they want like 100 + shipping for it...
so i called around some other bearing places
found a place called transmission technology
the guy there quoted me 37 for the part 27 for the shipping, so much better...
65 bucks i think i can manage...
i just hope when i put it all back together it works!

IanH

· #34 · Jun 21, 2008

can you get the bearing manufacturer and number of the race ?
If so try the bearing wholesalers, like SKF

triplefour

Discussion Starter · #35 · Sep 3, 2008

ok long time with no update sorry about that. as of about a month ago i got my beast back on the road! i never did get the transmission fixed. i did however totally luck out and find ANOTHER parts car ...standard 91 nx! bought that for 100, towed it and did the ol' swap-er-roo again.... getting good at changing trans's

at first when i got it back together my heart was skipping beats cause it sounded horrible and wouldnt rev high...
i figured out i forgot to attatch one of the sensors on the air filter...
after i figured that out my heart returned to normal and i was like
w00000h00000000! and i went zooming all over town.
then the fuel pump problem started acting up again (took care of it though, see other thread)
so yeah....transmission problem: case closed! thank you all for your help...sorry i couldnt be the hero and actually repair the trans itself but hey at least im back on the road!
but now i sort of have another problem..
one of the belts squeals when i start...and i think its the one connected to the water pump...is that the timing belt? would this cause me to lose some acceleration? i feel like sometimes i have tons of power, and other times it kind of lags...i know nothing about all those belts and pulleys and how tight stuff should be but if its squealing i need to tighten something..but what??
thanks again!!
-dev

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