Transfer case slips out of gear..

[Jason Mills]

Rebuild in process

I have come upon a couple of questions during this rebuilding process that I am wanting others opinion about.

First: What type of puller is needed to remove the pressed on bearings on the driven shaft? I suspect I will take it to a machine shop, but I am curious as to how one WOULD remove the bearings at the home shop.

Second: I have two transfer cases apart, and I am comparing the collection of parts to hopefully select the best of each.

My question is which is more important, the actual teeth of the gears, (having at best a slight pitted appearance, but with out a pitted texture to the touch) with some discoloring in the "race" that the bearing running surfaces. The worst gear happens to have the best race inside the gear, but the most rust and pitting on the teeth.

So is the bearing surfaces more important to keep the shaft running true?

Can the gear teeth be dressed to some small extent?

The best gear that I have appears to have had the roller bearings race brinelled somehow. I would like to use this gear, but if the inner race is not any good,

Or do I scrap all of the parts and start over..

[Charles Talbert]

I have come upon a couple of questions during this rebuilding process that I am wanting others opinion about.

First: What type of puller is needed to remove the pressed on bearings on the driven shaft? I suspect I will take it to a machine shop, but I am curious as to how one WOULD remove the bearings at the home shop.

Second: I have two transfer cases apart, and I am comparing the collection of parts to hopefully select the best of each.

My question is which is more important, the actual teeth of the gears, (having at best a slight pitted appearance, but with out a pitted texture to the touch) with some discoloring in the "race" that the bearing running surfaces. The worst gear happens to have the best race inside the gear, but the most rust and pitting on the teeth.

So is the bearing surfaces more important to keep the shaft running true?

Can the gear teeth be dressed to some small extent?

The best gear that I have appears to have had the roller bearings race brinelled somehow. I would like to use this gear, but if the inner race is not any good,

Or do I scrap all of the parts and start over..

We use a bearing splitter in conjunction with our own shop made fixture for bearing cone removal.

I understand what you are saying about the tooth pitting, etc. It is typical to see it, and is most likely the result of water being mixed with the oil at some point. At best it will cause accelerated tooth wear because rust has attacked the hard surface of the teeth that is only a few thousandths deep on a new gear. Once the hardened portion is attacked up to a point, then wear takes place much faster because metal to metal contact of unhardened tooth surfaces become in contact with each other. It is virtually impossible to visually see the extent of surface damage unless it has already gotten to the point of obvious abnormal wear. The pitted teeth will also cause an increased noise level within the gear box because smooth mating surfaces no longer exist. Your bearing race question is not nearly as big an issue because bearings can be replaced easily. We replace every bearing component in every case we go through as standard procedure, that of course takes care of bearing issues 100%. I would advise against attempting to dress gear teeth, the only way to do this would be with lapping compound and having a fixture to run the gears mated with each other just as they would run in the case. I think according to your description we know the teeth are deteriorated to some degree already, lapping in the most ideal circumstance will take more hard surfaced metal away. Obviously the ideal thing to do here is replace the gearing that has pitted teeth. That isn't that easy to do these days, really good gears are rather hard to come by, I have not seen any new ones in some time, however if you are fortunate enough to locate some, that may be your best bet. I wouldn't attempt to advise whether to use the ones you have without being able to inspect them. Even with some pitting they could have much life left. The application the truck will be used in can tell a lot. What I mean here is if the truck will be a weekend joy machine without logging lots of miles, the ones you have could go a long way. On the other hand, if it will be a daily driver, subjected to interstate driving, or repowered with a different engine offering higher speed capability, etc, you can see why using pitted gearing might not be a good choice. Another issue to consider is the oil used, there are oils available today that go a long way in coating tooth surfaces to the point of really quieting things down. Royal Purple synthetics is one we like, it coats and hangs on much better than anything else I've seen. 50 weight straight grade Royal Purple engine oil does a fantastic job in this case, it will run considerably cooler on this fluid also which will do a lot to hold further wear at bay if it isn't far advanced already.

[Jason Mills]

I will in fact use Royal Purple. That is an easy decision. luckily it is to be a weekend work horse, No interstate driving for me!

Charles, what do you do about/regarding the surfaces where the two shafts come together separated by the individual rollers?

If there is not much that can be done about the gears, probably there is not much that can be done about those wear surfaces.. do you reject gears often because that surface being discolored yet still smooth.

[Charles Talbert]

I will in fact use Royal Purple. That is an easy decision. luckily it is to be a weekend work horse, No interstate driving for me!

Charles, what do you do about/regarding the surfaces where the two shafts come together separated by the individual rollers?

If there is not much that can be done about the gears, probably there is not much that can be done about those wear surfaces.. do you reject gears often because that surface being discolored yet still smooth.

ALL bearings are replaced in ours including the loose needle rollers. You need to check the diameters of shafts and bores where the loose needles run to be sure they are within specified dimensions. If the surfaces are worn outside of specs, they will not run satisfactorily and replacement is the only option. Seldom is this the case. I've only seen that when abrasives were in the oil that caused irrepairable damage at all wear points.

[Jason Mills]

Charles,

Thank you for your response and guidance.

Yes I am replacing ALL the bearings as well. I don't really want to accepted the idea that I need to find new gears.. but I hear your experience telling me it is not out of the question, and in fact it may be a wise choice.

I was fussing with each clutch gear and the shafts they slide on. some of them are worn as well, and I was thinking: how nice it would be to have tighter fitting gears/splined shafts. I wonder what these were like when they were brand new.. and would better oil/ oil changes have prevented some of this wear.

[Charles Talbert]

Charles,

Thank you for your response and guidance.

Yes I am replacing ALL the bearings as well. I don't really want to accepted the idea that I need to find new gears.. but I hear your experience telling me it is not out of the question, and in fact it may be a wise choice.

I was fussing with each clutch gear and the shafts they slide on. some of them are worn as well, and I was thinking: how nice it would be to have tighter fitting gears/splined shafts. I wonder what these were like when they were brand new.. and would better oil/ oil changes have prevented some of this wear.

I'd like to have some new gears in stock, but we don't and it's scrape and scrounge each time we need one.

The clutch gears are not a tight fit when new, they are likely OK, but I'm not able to see them, so. Too loose here can absolutely be the cause for jumping out of gear, so look at it closely. Absolutely better oil would have preserved components much better. This is why we have done all the research and testing to find out what performs better, Royal Purple is tops in my opinion.

[Jason Mills]

Weeks later: I have again re-started assembly of the transfer case. In shimming the idler gear bearings, I have found that one of the new races seems to make a clattering noise when the gear is spun on the shaft.

How much noise is too much?

It has a sort of rough clacking sound to it.. so I took it all apart and did indeed find that any bearing spun in that one race makes a noticeable amount of noise, over and above the usual sound the rollers make. The same bearing spun in the race on the other side of the gear rolls smooth.

maybe this is kind of a no-brainer, is it time for another new race? Or am I just being neurotic?

[Desoto61]

The fact that it doesn't seem to make the noise in another race leads me to believe you're on the right track.

With the trouble involved in getting to those races, and the damage it could do if bad, I have to say I'd get a new one. Depending on where you got it they may exchange it for you, but even if not it's cheap insurance.

[Charles Talbert]

Weeks later: I have again re-started assembly of the transfer case. In shimming the idler gear bearings, I have found that one of the new races seems to make a clattering noise when the gear is spun on the shaft.

How much noise is too much?

It has a sort of rough clacking sound to it.. so I took it all apart and did indeed find that any bearing spun in that one race makes a noticeable amount of noise, over and above the usual sound the rollers make. The same bearing spun in the race on the other side of the gear rolls smooth.

maybe this is kind of a no-brainer, is it time for another new race? Or am I just being neurotic?

1 of 2 issues is happening, there could be debris under the race causing it not to press into the bore completely square, I'd press it out and check that. If that reveals nothing, absolutely replace it for sure as it is bad.

[Jason Mills]

I wonder if I messed it up putting it in...? It did not feel rough, to my fingers, but sure sounded bad.. I have all ready ordered a new one, and it should show up tomorrow.

Thank you. I appreciate your confirming of what I was suspecting, and yet not feeling confident due to my lack of experience. I now have more experience, and more confidence. This rebuilding process is taking a lot longer than I expected, BUT it is also teaching me much more than I could have imagined.

Jason

[Jason Mills]

I may be going overboard here.. Not sure at what point noise of a clean dry bearing being spun in the race is acceptable, and at what point is too much noise.

I installed a new race in the idler gear this afternoon, and found it to be just as noisy as before.. OK so I did not ever check to see if it was the bearing or the race, although I thought It made more noise in one race than the other.. I know it did, at least in my mind..

but the question as become, why is one bearing making a clacking noise, when the other new one is fairly smooth sounding, and the old used one is also smooth sounding. OR is it that the bearing is a bad one?

most likely I will order a new bearing anyway, as saving thirty dollars is not worth the headache of getting it wrong.

If anyone has an opinion, please feel free to share it, or ask questions.

Thanks
Jason

[Frank Irons]

Jason, you are going overboard. Don't spin your bearings dry, they do not run that way. Lube them up and then give them a spin, all should sound normal. I have never found a problem with bearing quality, after all they do it for a living, LOL.

Frank

[Jason Mills]

Got it. I will chill out.

[Charles Talbert]

I wouldn't chill out just yet

Got it. I will chill out.

I'll have to disagree with Frank in this case.

It hasn't been long ago that I unwrapped a new Timken and installed it. I got virtually the same response that you have described. I always oil bearing assemblies as I build up a unit regardless of what it's going in. I would assume we deal with bearings more than you do, and maybe as a result are a little more sure when something just isn't right. You are SMART to not just assume that new parts are good. We probably open up more new parts to find them bad right out of the box these days than ever before. What I found upon disassembly and inspection was that the inner race of the cone had a chunk of metal flaked out of it, thus as the assembly rolled, each roller dropped into that low spot as it passed over it. Had I not went back and found this, catastrophic failure would have been the next phase, and no telling what else would have been ruined. I have also had issues with bearings that I could never see, but replacement stopped the issue, so obviously something was there that I was not able to see.

I would highly recommend you remove the cone and inspect visually between the rollers using a good light, you may see your problem, but if you don't, I agree with what you first said, replace it, it could be a flat spot that may be hard to see. Oiling it up and assuming all to be well is not a smart road to take and could cost you huge if you overlook an issue. Trusting anyone because it is what they do or is how they make their living makes no sense at all, we all are prone to mistakes and oversights, it happens. Don't fall victim because you just said "ahh it will be ok," personally, I would never give that advice. Always better safe than sorry. I would much rather advise someone to be on the safe side than I would to say don't worry about it only to learn my advice cost them big bucks when something failed.

[Frank Irons]

I agree with Charles don't just lube it up and assume it's good. What I was suggesting is that spinning the bearings dry will produce strange noises as noted when the roller cages rattle. If the bearing is bad you should be able to feel it as the assembly is turned but do it with lubed up bearings. Cleanliness in the assembly is also important, any lint, dust, dirt or foreign material will affect bearing performance and life.

Frank