So I took apart my 5spd tranny last night. And what do I see? All the differential bearings pour out with the fluid. They were totally ripped to shreds. One actually got jammed into the driveshaft, don't ask me how. Its a total mess. I'm rebuilding the tranny shortly. I guess i found out what happens when your driveshaft has a little play, it eventually just breaks. After the bearings broke, I was able to move the driveshaft almost 3/4 of an inch! Ok I don't know how useful this is to anyone, but i just felt like posting.

 

The same thing happened to mine...luckily i was still 5K under the warranty so I went and got it fixed. I think its a common problem with our 5 speeds.

Are there stronger bearings that we can get to prevent this?

 

Perhaps, but one of the things ericdwong found out is the bearing tolerances were not correct...bearings were overcompressed during install. This would indicate that if someone simply rebuilt the tranny with the tolerances stated in the Nissan service manual, you should extend the bearing life.

That being said, a trip to a bearing shop (should be several in any good-sized down) would show whether or not there are improved bearing available.

This is THE reason for 4th gen 5-speed failures. I haven't read any of any other tranny failing for any other reason.

 

At what mileage does this failure usually occur? I mean, I understand there is no specific number, but your own experiences would be very helpful. I'm about to purchase a 5 speed with 77k miles, that hasn't had any problems with the transmission yet. But, I could probably get the guy to cut his price a little if I know that it is going to fail at 80k or 90k. Thanks!

Ashok

 

Mine was at 94,000Km..I guess thats close to 60,000 miles.

 

Don't just replace the bearings, measure the preload on them this time. You need special gauges to measure this, then you will need to order the correct shims. If you only replace the bearings, changes are VERY good that down the road (no pun) your bearings will fail on you again. www.motorvate.ca has an excellent write up on this procedure.

The bearings don't fail because they are weak, they fail because they have excessive preload on them. Shim your tranny correctly and the bearings should last the life of the car. Provided you feed them good clean oil!

 

ug, another bearing failure. I worry about mine all the time now. Why won't Nissan do a recall and have these fixed?

 

I work in the engineering department (manager) of the US branch of a top five bearing manufacturer. I am involved in many technical aspects of the bearings we produce including design, application, and failure analysis. One of my areas of expertise is automotive bearings including driveline components.

If someone would like to post some photos of a failure (don't bother if it is catestrophic) I'd be happy to offer some expert opinion. For reference, please include the industry number which should be stamped on the bearing as well as manufacturer if it is visible.

 

Alot of 4th genners have failures at 60K miles. Mine were done at 125K miles. You'll know that your bearings are going when you start to hear gear whine in 2nd, 3rd and even 4th gear. In 1st gear the gear whine is somewhat normal, so you can't really attribute the noise to the bearings. Mine got so bad that peopl walking 20 feet in front of me could "hear" me downshifting a gear. Also, when they fail, your car and tranny are still completely drivable, but the tranny is very noisy.

DW

 

One member here, ericdwong, rebuilt his bad-bearing'd transmission himself and might have some pictures/info for you. I posted on the 4th gen forum requesting his assistance.

Thanks for the offer!

BTW my transmission failed at 70K miles with the same failure...failed driver's side differential bearing.

 

anyone have an idea on why i hear something like a CLICK into 2nd and 4th ? sometimes when i shift to 2 or 4 it "CLICKS" in. dont know what this is but it just started a month or two ago

 

Follow this link for pics of failed bearings in a 4th gen Maxima

Failed Bearings

 

Unlike those bearings, mine came separately, one by one in the fluid. haha. The metal piece that enclosed them was just churned up into a metal wire. The tranny had 90k.

 

So I have a friend who is a mechanic at a Nissan dealership, and he is going to look over the 5 speed 99 SE that I'm buying. Is there some specific term I should use to make sure he looks at the right thing? From motorvate.ca, I'm thinking something like "Check the preload on the transmission differential carrier bearings." I'm not all that experiences with the finer details of clutches - that's why I'm askin'. Thanks!

Ashok

 

Motorvate's site is telling you what to look for once the tranny is open. In normal driving, just listen out for gear whine in the gears 2 and above. If you hear it, then its a symptom that the bearings are on their way out.

DW

 

Have the mechanic check for lateral play in the driver- and passenger-side driveshafts right where they enter the transmission. Any play would indicate a failing differential bearing. Also have him check for any leaks out of the driveshaft seal at those same locations.

 

I don't believe that Nissan cares much about our problem. There is no recall and there won't likely be one since it's expensive and most cars are already out of the powertrain warranty (except some '99s and lower mileage cars). I had my driver side seal replaced at 51k, but unless the seal leaks again I doubt Nissan will cover the bearings. I mentioned it to service, but since a transmission job is much more expensive than replacing a seal they would only change the seal.
I feel like I have some play in the axle, but that didn't even convince Nissan.
-hype

 

So you don't think it's necessary to have him open the tranny and measure the preload? Time is not an issue for me or him - I just want to make sure (as much as possible) that I'm not going to develop a problem in the future. Thanks Kev!

 

That would be very expensive for him to do. He would have to completely remove the tranny to inspect the preload on the bearings. You're talking an easy 8 hours of labor. I would think that would be too much for a pre-purchase inspection. Besides, checking driveshaft play would tell you whether or not there's a bearing failing. If that 99 you're looking at has anywhere near typical miles (60K+), it would already be showing signs of a bearing failure if the bearing preload were excessive, and would therefore almost certainly show increased driveshaft play.

Just check the driveshaft play. It's a quick but fairly accurate check in this case.

 

Ok I cannot figure out what measuring the preload means. What are you measuring? What exactly do you do? Someone explain it to me in 3 year olds terms. Where do you stick what to measure it? What tool do you use? And if the measurement is off, what the hell is a shim? Where do I get one? How do I install one. I just wish this subject was clearer.

 

Okay, think of the differntial assembly (with the bearings installed on both ends) as being sandwiched between the two halves of the tranny case. Shims are just thin pieces of metal used to separate two parts a little...shims come in different thicknesses. If you added no shims to the differntial, it would clunk around side-to-side inside the case due to free play. You add shims between the differential and the bearings (which get pressed onto the ends of the diff) to take up the slack and remove the play...you force the bearings to stick out a little bit further on the differential. At some point, you'll add enough shims that the differntial starts to get squeezed inside the case. THIS is the pre-load. The preload on the differential is imparted on the bearings. So, if you add too thick of a shim stack, you'll squeeze the bearings too much. THIS is what is being theorized as the failure mode for the 4th gen 5-speed trannys...too much preload on the diff bearings causes them to fail.

Make sense?

 

Thanks Keven - that makes total sense. I thought pulling the tranny only took an hour or two. I will do as you command, Sensei.

 

Okay, I took a look at the pics from the link. The pictures are pretty decent, but do not always tell the whole story. Based on just a couple of pics, here is my basic assesment:

Bearing on the right failed first and damage to the left was likely a result of debris (probably from the right bearing). Spalling of this nature (center of race and rollers) does not necessarily mean that the preload was excessive as the website suggests. Based on seeing MANY warranty returns from all kinds of drivelines, excessive preload does not usually show up this way. If the preload were too high, I would expect:

1) Early failures - not at 60K
2) Lots of wear to the ends of the rollers where they meet the large end rib. This rib is what takes the preload and is not rotating - it is sliding motion here. Also expect discoloration or roller ends and/or rib.
3) Excessive preload will not exist for a long period of time. Wear will occur until you have endplay if enough wear occurs. This usually results in gear whine (improper mesh). Again, I doubt excessive preload would go to 60K

So what do I think the problem is? Without seeing the parts or at least more photos, I cant say for sure. Based on the photos, the bearings may have just met the end of their fatigue life. Debris or insufficient lube may also have been the cause, but it is a little difficult to tell when the bearing gets to that stage (and very tough with just photos to go by).

Someone asked about a going to a distributor and getting a premium bearing. Unfortunately, most distributors will not be able to help you with this. Right now in the industry there are many enhanced bearings available offering lower torque, greatly enhanced fatigue life, etc. We work with the major OEMs with this type of product and bearing distributor houses (or the Nissan dealer) will simply have standard grade bearings.

One last thing. If someone can provide the full industry part number for BOTH differntial bearings, I can calculate the actual force applied by the 0.0064" excessive preload noted in the website.

 

What's a gear whine?
What am I listening for?

I can hear a "ssssshhhh" when I turn the radio off. And the sound changes a bit when I push or pull the gear stick. (When it's already in gear, and I just lean my hand on it, and it pushes it up or down).

 

Gear whine, or noise, is just that - a whining sound. Usually (but not always), the whine will be more apparent under load OR coast, but not both. Just means that the gear teeth are not meshing in the ideal location resulting in noise. If you have ever watched SCCA Trans Am racing on TV with an in car camera just about all you hear is gear whine. This is not because their gears are bad or impropperly meshed, rather, it is due to the straight cut gears which are used but the sound is similar.

NOTE: It is BAD to drive a stick shift car with your hand on the stick. Just causes unecessary wear.

 

I'll keep it in mind.
But I am hearing a "rubbing shhhhhhh". What is that?

 

I hear whine in first gear and have since I bought my car, but as soon as I shift into second, it goes away. I thought all manual cars whine in first gear.

 

Hi Gary,

Thanks for looking at my bearings.

The other bearings have no sign of debris in the gear oil, or of running with out oil. As they are higher, they would of shown the sympton first. Only the diff carrier bearings have the spalling.

The oil level was never more than 2-3 mm lower than the "oil inspection hole" (if you know what I mean) When I changed the tranny, I ran a magnet through the used gear oil to look for debris. I did not find any pieces.


Getting back to your first point. If we assume the pre-load is 4-6 thou too much, wouldn't the bearing be ok for a while? Then the bearing surface would fatigue, start to "crumble" and allow the race to easily to compress allowing more free play. This allows too much play for the CV seal to contain the gear oil and it starts to leak.

Does the above sound possible?

I will get the manufacter and part number to you.