[IanH]

It sounds like the noise is wheel speed, what happens in different gear at same speed ?
If so its not the clutch!!
list is Wheel bearings, axles, final drive or tires ( and dust shield as mentioned)
If you are coasting and swing wheel from side to side does noise change depending on which way you are turning.
Look here for parts in your area......
Car-Part.com--Used Auto Parts Market

 

[IanH]

wow on that car-part.com i found a transmission in texas for 150$ but how could it be so cheap? i want it cheap but i want it to work...

Its a matter of supply and demand, small cars with manual transmissions are not popular here in Texas and the manuals last a long time.
When i had a 1990 legacy with a blown final drive they were rare here in Texas (1996-7).
I purchased the Car in New Mexico where they were much more popular.
But the wrecker yards had them in stock and complained they couldn't sell them. So i got a low mileage one for $300 out of a 1992 locally just by calling around.
I agree you need to try and find one locally, with a warranty, shipping the thing back and forth if you have a problem doesn't make any sense to me.

 

[IanH]

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 ?

 

[IanH]

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.

 

[IanH]

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]

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.

 

[IanH]

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.

 

[IanH]

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......

 

[IanH]

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