# cv shafts



## sentra92 (Sep 7, 2002)

Hello,

This is strange enough nissan mechanics I talked to at 2 locations could not answer.
I have 1992 Sentra 1.6, 4speed manual trans.
My 5 spped trans went bad so I got a used one and they put it in for me. After that the axles/trans were making real loud vibration.
The guy who put it in said the used trans was bad so I tried another. This time 4speed trans. Same result, heavy vibration. I checked my front wheel bearings - they were good and I replaced both driveshafts. It didn't help. So finally I found it in Chilton manual that 2 Kent-Moore tools (J-34296 and J-34297) are required when installing driveshafts otherwise vibrations will occur. So what is this all about? Do I really need these tools? 
How do they work?

Thanks

Paul


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## Centurion (Sep 5, 2002)

I used to work at a Nissan dealer and we never used those tools for driveshaft replacement. I've never heard of them before!?  Never had any problems with come-backs either.


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## sentra92 (Sep 7, 2002)

One of the new shafts had a white dot painted at the tip of the inner end. That had to be there for some reason but I just don't know.


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## UnderDog (Jul 14, 2002)

.


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## OPIUM (Aug 18, 2002)

First things first... Are you sure you have the correct drive shafts? The drive shafts vary between ABS and Non Abs. So do you have the correct ones?


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## sentra92 (Sep 7, 2002)

Of course I have the right ones, no ABS here. They look just like the original which were good before taking them out, and make the same noise.


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## Yosho (Aug 11, 2002)

Centurion said:


> *I used to work at a Nissan dealer and we never used those tools for driveshaft replacement. I've never heard of them before!?  Never had any problems with come-backs either. *



Agreed... I also used to work at a Nissan dealership and no one used those special tools for driveshafts. I don't think we even had them. You'll find in all Nissan FSM's that Kent-Moore tools are spec'd in the "Preparation" section under "Special Service Tools" at the begining of each chapter/section. Some of the specialized tools we did have available, but nothing for something as simple as replacing a driveshaft.


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## sentra92 (Sep 7, 2002)

I did more research on the subject.
The white dot I mentioned is just the what the axle re-manufacturer painted to tell who made it in their shop.
I purchased ALLDATA subscribcion. They show these Kent-Moore tools as temporary seal shileds, however they have a notch so it may be it is a dual purpose tool. What I am thinking now is that the axles, which are of different lenght, when inserted in the tranny may need to be turned slighlty in relation to each other.
That is something transmission expert may know about.


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## Centurion (Sep 5, 2002)

Yeah I checked the FSM and that tool protects the oil seal (huh?? whatever...).


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## sentra92 (Sep 7, 2002)

hi,

if you check Nissan Sentra/Pulsar/NX 1982-96 repair manual (the newer Chilton series, part number 52700) page 7-6 you'll see:

"Installation of the halfshafts may require a special tool for the spline alignment of the halfshaft end and transaxle case...Kent Moore tool number is J-34296 and J-34297"

I am pretty sure this is not crap because I changed 2 trans and 2 pair of axles - nothing else was done around that time on the vehicle. I guess I am just a not too happy owner of some experimental, undocumented release by Nissan.


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## Guest (Sep 14, 2002)

When I swapped out my blown 5-speed tranny for a 4-speed, I also had this problem. The cause was the length of the drive shafts. They look nearly identical, with the exception of the 5-speed half-shafts being almost 1" longer. If your running the longer half-shafts then what is happening is that the shafts are binding because of a lack of clearance inside the cup of the shaft. This causes an annoying vibration that is hard to trace. This problem is amplified when the car is lowered. Hope this helps.


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## sentra92 (Sep 7, 2002)

paulb said:


> *When I swapped out my blown 5-speed tranny for a 4-speed, I also had this problem. The cause was the length of the drive shafts. They look nearly identical, with the exception of the 5-speed half-shafts being almost 1" longer. If your running the longer half-shafts then what is happening is that the shafts are binding because of a lack of clearance inside the cup of the shaft. This causes an annoying vibration that is hard to trace. This problem is amplified when the car is lowered. Hope this helps. *


This sounds pretty interesting. How do I find a shorter axle? Will B12 axle be shorter? If not, what year shoud I try?

Thanks


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## Guest (Sep 15, 2002)

B-12 half-shafts is what I had to go to. This solved all of my problems, with the exception of being out a few bucks to buy another set of axles. Everything fits perfectly.


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## sentra92 (Sep 7, 2002)

b12 axles won't work for me because the axle's transmission side has only 24 splines instead of 25.

Out of a number of remanufactured shafts I checked the driver side length is almost identical for b12 and b13/14 , within 1/4 of an inch. 

The passenger side b12 is indeed about 1 inch shorter than b13/b14. 

b13 and b14 use same axle.

I forgot to see one (b13) with ABS. Are they shorter?

I can't even get a b12 and b13 and build one which is shorter and has the right number of splines on it because b12 is shorter on the spline area that won't fit b13.

Any ideas?

Thanks


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## Guest (Sep 18, 2002)

Hmmm, I wasn't aware that the splines were different. Mine worked fine, and have been in use for the last two years. Well, if that's the case, then I wish you luck on finding the correct answer.


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## johnand (Apr 30, 2002)

4 speed manual, 5 speed manual, and 4 speed auto B13's, ALL use the same shafts. 3 speed auto uses different shafts. The only difference between ABS and non-ABS shafts is the tone rings. So an ABS shaft will work fine in a non-ABS car, but not the other way around.

Sounds like the problem is something other than the trans or the shafts based on your replacements. What about the flywheel? Did they surface it and balance it? What about clutch and PP?

If you still think it is the shafts, take the shafts out and rotate them 90 degrees and see if the vibration changes.


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## sentra92 (Sep 7, 2002)

No flywheel was ever touched when swapping transmissions.
What other Nissan year and model transmission will fit my sentra 92, 1.6? Maybe the tranny is not sentra tranny? I called dealer they said they can't tell noting about transmission by its serial number. They only give you the original part info. So how can I find out more about the tranny? I called a couple of yards they said nothing but sentra 91 and 92 tranny will fit my sentra 92.
Another thing, maybe it has to do with Californian/Canadian/Other differences?


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## johnand (Apr 30, 2002)

All manual transmissions for the 1.6L from 91-up will fit your B13. The only difference is the 93 up have the electronic speedo gear in the trans. But, all you have to do is swap your non-electronic speedo gear with the 93-up transmissions. I have a 93 transmission in my 91 and it fit perfect. No difference in the trans from CA/Can/other. If it bolted up to your 1.6L engine it has to be out of a Sentra, as I am almost 100% positive the 1.6L was only available for the Sentra.

I still suspect flywheel, clutch, PP, wheel bearings, or inproper installation. If 2 transmissions and 2 sets of shafts all had the same symtoms, I doubt it is either of them.


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## sentra92 (Sep 7, 2002)

the noise seems to be coming from outside of engine/trans but I may be halucynating. last time I checked the bearings they were not loose, pretty quiet. Maybe it is still a bearing under heavy load. Vibrations start around 30/mph. They are independent of engine on/off, cluch on/off. I guess the only way to find out is to beat the bearings out which will probobly trash them. 
If it is a bearing, how could it happen? Can you damage the bearing just by taking the axle out? Maybe the guy used an air gun to tighten the axle nut? So how do you remove pessed in bearings and separate the hub from knuckle without destroying them?
thanks


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## johnand (Apr 30, 2002)

Unfortunately the front wheel bearings are not "removable" on the front. Once you remove them they have to be replaced. You need a good shop press to replace them. The bearing run ~$50 a side from the stealership and a couple of bux each for the inner and outer seals. If you have much more than 100K on the bearings, they are probably due for a change. They can damage the bearings one of 2 ways. First, if they damage the seals by putting the shafts in w/o paying close attention to not damage the seals, water and dirt will get in the bearings and damage them. Or, if they ever moved the car around w/o the shafts in the car, it wil trash the bearings, as the shafts help support the wheels.


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## SergioCR (Sep 18, 2002)

paulb said:


> *When I swapped out my blown 5-speed tranny for a 4-speed, I also had this problem. The cause was the length of the drive shafts. They look nearly identical, with the exception of the 5-speed half-shafts being almost 1" longer. If your running the longer half-shafts then what is happening is that the shafts are binding because of a lack of clearance inside the cup of the shaft. This causes an annoying vibration that is hard to trace. This problem is amplified when the car is lowered. Hope this helps. *


That sounds like the problem i have in mine but it is 5 speed. Now, is that sound something like a low frequency vibration? like the wheel bearings are about to die? or is it different? mine sounds a lot when going at the highway... i thinked that the problem was the rear bearings so i changed them, also changed the front bearings just in case and the problem it's still there... i have noticed some clearance at the drivers axleshaft it moves like 2cm in and out with my hand, the other side moves in and out like 1cm.... could that be the problem i have?


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## SergioCR (Sep 18, 2002)

johnand said:


> *Unfortunately the front wheel bearings are not "removable" on the front. Once you remove them they have to be replaced. You need a good shop press to replace them. The bearing run ~$50 a side from the stealership and a couple of bux each for the inner and outer seals. If you have much more than 100K on the bearings, they are probably due for a change. They can damage the bearings one of 2 ways. First, if they damage the seals by putting the shafts in w/o paying close attention to not damage the seals, water and dirt will get in the bearings and damage them. Or, if they ever moved the car around w/o the shafts in the car, it wil trash the bearings, as the shafts help support the wheels. *


Seems to be that everybody has this problem here...  i replaced both front bearings and the rear hubs with new ones and still have the same vibration.... starting to suspect about driveaxles... have made the same tests and the vibration starts at about 45MPH, doesn't matter if engine is runnning and with clutch in/out or transaxle in neutral... the only thing i have noticed is that if the car lifts himself a little up just enough to still keep the wheels on ground "like when going fast on a road with some downside" the vibration stops at all...


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