Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: greggmo on October 31, 2006, 10:41:24 AM

Title: ok guys here's a tuff one
Post by: greggmo on October 31, 2006, 10:41:24 AM
just a question for you clever ones out there. my front pinion bearings keep destroying them selves. when i get em fixed again this will be the third set. the last sat where done by a professional and it seems we still have the same problem. it is not a lubrication problem because the last time they went the pinion oil seal was leaking oil so the is obviously oil there. it is just real strange and it is starting to piss me off now. at the moment i cant afford the new bearings but when i can i don't want them just to be another waste of money. any ideas guys???
Title:
Post by: Mike Pavelin on October 31, 2006, 10:50:21 AM
Are you setting the rolling torque properly during installation?
Title:
Post by: MK1 on October 31, 2006, 10:54:49 AM
Is the bearing seat slightly ovaled or worn?
Title:
Post by: eastryjeep on October 31, 2006, 11:02:16 AM
Are you using OEM replacments or not? If not are you sure the replacments meet all the manufacturers specs.
Title:
Post by: isle of man on October 31, 2006, 11:19:58 AM
more information needed.............what lift have you?(if any) and what tyres are you running?(size) also do you have a double cardigan propshaft?(on the front) is it both bearings that fail the upper and lower?


peter henry
Title:
Post by: Mike Pavelin on October 31, 2006, 11:27:17 AM
Quote from: "isle of man"
double cardigan propshaft?

peter henry


If not, a couple of nice wooly sweaters will do.
Title:
Post by: MK1 on October 31, 2006, 11:28:17 AM
Quote from: "Mike Pavelin"
Quote from: "isle of man"
double cardigan propshaft?

peter henry

If not, a couple of nice wooly sweaters will do.


I prefer a big fleece type garment myself.
Title:
Post by: isle of man on October 31, 2006, 11:33:10 AM
ok ok cardan








peter henry
Title:
Post by: greggmo on October 31, 2006, 11:37:39 AM
ok. no i dont have a cardin joint as it is a yj. over all i gues there is about 4.5 of suspension lift. running 33,s+ 4.88 ring and pinoins and yes both bearings are knacked each time and they have been tomken bearings each time. as i said the job was done properly and all the right settings made at the time of install.
Title:
Post by: Mike Pavelin on October 31, 2006, 11:40:57 AM
How are you setting the pinion up when installing the bearings?
Title:
Post by: UKJeeper on October 31, 2006, 11:44:57 AM
Hmmmm, 4.5" lift and no SYE?  :? Is the T case dropped? If your running a stock driveshaft and no t case drop, i'd be wondering about the driveshaft angles.
Title:
Post by: UKJeeper on October 31, 2006, 11:46:21 AM
Quote from: "Mark Barrs"


I prefer a big fleece type garment myself.


I thought you might prefer a nice rollover...   :oops:  :wink:
Title:
Post by: MK1 on October 31, 2006, 11:49:15 AM
:smt019
Title:
Post by: Mike Pavelin on October 31, 2006, 11:50:02 AM
Quote from: "UKJeeper"
Hmmmm, 4.5" lift and no SYE?  :? Is the T case dropped? If your running a stock driveshaft and no t case drop, i'd be wondering about the driveshaft angles.


SYE???

It's a YJ front axle.

The front prop only spins when in part time (assuming you still have axle disconnect) and it already has the dual sweater (double cardan) propshaft. Might be worth checking the front UJ isn't binding on itseld on full articulation I guess but other than that, it is only running at low speed and only occasionally so I can't see it being too much of an issue.
Title:
Post by: MK1 on October 31, 2006, 11:52:46 AM
Quote from: "Mike Pavelin"
SYE???

It's a YJ front axle.

The front prop only spins when in part time (assuming you still have axle disconnect) and it already has the dual sweater (double cardan) propshaft.


You don't get any of this nonsense with a good ol' CJ!
Title:
Post by: UKJeeper on October 31, 2006, 11:55:16 AM
Quote from: "Mike Pavelin"


It's a YJ front axle.



DOH. Missed that bit. I'm an idiot.  :oops:
Title:
Post by: Dingo on October 31, 2006, 12:35:52 PM
Are the props of stock length?
Title:
Post by: Asylum on October 31, 2006, 12:36:05 PM
Aparently, lack of backlash may cause noise, overloading, overheating, or seizing and failure of the gears or bearings. But after reading the below link several times (I am thinking of doing the work myself when I change my R&P's on my froader) as too little pinion bearing preload diminishes load-bearing capacity as the load-bearing surfaces between rollers and cup are decreased. Too much preload increases friction, resulting in excessive noise, heat, and rapid wear. That would be my guess  :prayer:

Clayt
 :D
Title:
Post by: greggmo on October 31, 2006, 12:49:35 PM
the pinion does run all the time as i have a no-slip in there but i cant see how this would make any odds. the back one runs all the time and that has not got the same problem.
Title:
Post by: isle of man on October 31, 2006, 01:09:19 PM
i'm thinking check the prop joints and length both compressed and extended and then if all good the pumpkin must be u/s.

no woolly pulleys there.......yerr yerr i know




peter henry
Title:
Post by: MK1 on October 31, 2006, 01:13:00 PM
Quote from: "isle of man"
and then if all good the pumpkin must be u/s.


It's a good day for it, you can make a silly lantern type thing out of it!
Title:
Post by: greggmo on October 31, 2006, 01:22:56 PM
thanks for you input guys.
Title:
Post by: isle of man on October 31, 2006, 01:22:57 PM
Quote from: "Mark Barrs"
Quote from: "isle of man"
and then if all good the pumpkin must be u/s.

It's a good day for it, you can make a silly lantern type thing out of it!



i'm thinking your on-a-roll.


ter der.


peter henry
Title:
Post by: MK1 on October 31, 2006, 01:28:01 PM
:smt005
Title:
Post by: greggmo on October 31, 2006, 06:36:50 PM
any more ideas?
Title:
Post by: Mik on October 31, 2006, 10:02:20 PM
:-k Despite correct nut torque and bearing preload, worn yoke splines are allowing axial movement and backing the nut off.


Hiythankyew :smt023
Title:
Post by: MK1 on October 31, 2006, 10:16:48 PM
Quote from: "Mik"
Hiythankyew :smt023


Shut up smart arse!
Title:
Post by: greggmo on October 31, 2006, 11:08:19 PM
hey ya mik dood. the nut is tight as fook and didnt move when i tried to tighten it. do you still think the same mate??
Title:
Post by: Mik on October 31, 2006, 11:56:14 PM
no (http://http://www.bike-pix.com/forum/images/smiles/sad002.gif)
Title:
Post by: greggmo on November 01, 2006, 12:09:43 AM
it realy is doin me head in now. it is just wierd. keep thinkin guys cos i need to sort it. 8)
Title:
Post by: Bubba on November 01, 2006, 06:37:28 AM
its a spensive pain
Title:
Post by: eastryjeep on November 01, 2006, 01:04:35 PM
If you look at the ring gear does it have an even wear pattern across the flank of the gear teeth?
If so, that's good, if not, and there is local pitting or heavy localised wear it  could indicate the pressure angles of the ring gear and the pinion are different and therefore not meshing correctly or that the diff housing itself is distorted.
So, if this problem first came to light after an R/P upgrade that is what I would suspect, or if it came to light after giving the axle assembly a good clout whilst off road I'd tend to lean that way instead.
Title:
Post by: MK1 on November 01, 2006, 01:09:15 PM
It's pretty much a certainty that it is/was set up right. Kev and 'the professional' (no, not Bodie or Doyle) will have done it right.
Title:
Post by: eastryjeep on November 01, 2006, 01:30:48 PM
My vote goes to a knackered diff housing then.
Unless they've got a digitizing machine to the check 3D alignment you'd never know, a few tenths of a thou' distortion would be easily enough.
Still, that said, just because a part is new doesn't mean it's not faulty!
Title:
Post by: MK1 on November 01, 2006, 01:33:36 PM
Quote from: "eastryjeep"
My vote goes to a knackered diff housing then.


Other than the drive line issues mention earlier, then I'd agree.  :smt102
Title:
Post by: isle of man on November 01, 2006, 03:11:35 PM
so it would seem i was correct the pumpkin is u/s.




peter henry
Title:
Post by: MK1 on November 01, 2006, 03:38:53 PM
Quote from: "isle of man"
so it would seem i was correct the pumpkin is u/s.


Only time will tell, dear Sir.
Title:
Post by: Bubba on November 01, 2006, 09:08:43 PM
you would need some sexy toys to be able to measure proper
Title:
Post by: Mik on November 01, 2006, 09:13:50 PM
Quote from: "eastryjeep"
If you look at the ring gear does it have an even wear pattern across the flank of the gear teeth?
If so, that's good, if not, and there is local pitting or heavy localised wear it  could indicate the pressure angles of the ring gear and the pinion are different and therefore not meshing correctly or that the diff housing itself is distorted.

 :-k Hmmm, technical intrigue....

Whilst what you say is true the ring gear pattern in this case is of zero value. The pinion preload has dissappeared on at least one previous occasion and bearings only have been replaced. The Ring and Pinion have been re-installed.

How would diff housing distortion lead to pinion bearing preload loss ?
Title:
Post by: isle of man on November 01, 2006, 09:30:51 PM
Quote from: "Mik"
How would diff housing distortion lead to pinion bearing preload loss ?


if the prop and half shaft are not binding the oil is at the correct level the pinion bearing have been fitted and set by a professional a quality part has been used then the logical answer is the pumpkin is causing stress on the bearing.

have i missed something?


peter henry
Title:
Post by: chrisjones on November 01, 2006, 09:33:55 PM
Is one of the bearing seats damaged so that the bearings aren't sitting properly in line?  Or...I know it's a long shot, is the pinion shaft out of alignment.  On second thoughts it can't be the shaft else you wouldn't get an even contact pattern.

Is it clear what's happening, are the bearings going, or is the R&P setting going off?  If it's the bearings are they just being starved of oil somehow?

If the pinion nut is still tight, surely the only thing which can cause the preload to go is if the crush washer is taking a beating somehow or the bearings aren't seating properly?? :?  :?
Title:
Post by: greggmo on November 01, 2006, 09:35:16 PM
i am still at a loss. it just dont make sence. the old stuff was as good as gold with over a hundred thou on it. i dont see how the deff housing can be fooked when up untill the regear all was cool. :smt088  :smt100
Title:
Post by: Bubba on November 01, 2006, 09:38:03 PM
i do see what you saying kinda sorta but i reely think its not the root problem but heck i am proly talkin out me ass
Title:
Post by: Mike Pavelin on November 01, 2006, 09:43:47 PM
So are the bearings discoloured as well indicating overheating for some reason or is the preload just disappearing?
Title:
Post by: chrisjones on November 01, 2006, 09:45:13 PM
I'm probably completely wrong, but surely you wouldn't be able to get a correct contact pattern if the pumpkin was deformed would you?

Is the new pioion shaft slightly under size?.... maybe??
Title:
Post by: greggmo on November 01, 2006, 10:03:46 PM
it is all still in at the moment so i cant say on the discolouration. i cant remember what the last ones looked like. :thinking:
Title:
Post by: MK1 on November 02, 2006, 10:14:42 AM
The thinking is that there must be some misalignment somewhere in the system. This is after checking bearing seats etc.

If not driveline, UJs etc, then surely in the diff case/axle?
Title:
Post by: eastryjeep on November 02, 2006, 10:27:09 AM
Ok, so troubles have started since a re-gear, sorry, I was not aware of that!
I think we can more or less rule out the driveline now unless you dropped the T/Case or rotated the diff at the same time, but just in case some evil little pixie is waiting to bite me in the arse for that statement, get an inclinometer (fancy adjustable spirit level) and check the transmission output shaft vs the pinion shaft & ensure they are parallel. If they are great, if not, make them so! Misalignment here makes universal joints into very cross cardians, fleeces, woolies etc!
A rotated diff housing would obviously starve the bearings of oil and cook the wee buggers, and if they are getting hot then so is the pinion shaft which will increase slightly in diameter and get longer by a thou' or so and then all your pre-load has gone straight out the window! This would be true for oil starvation for any reason too.
Bugger this really is a frustrating one in't it?
Title:
Post by: isle of man on November 03, 2006, 09:52:01 AM
it has come to my attention that i may have missed something with the pumpkin........when the ring and pinion was replaced can you recall if the oil deflector and cup was retained?




peter henry
Title:
Post by: isle of man on November 03, 2006, 07:06:07 PM
ok,
to take this a little further i can now give the part numbers of the parts i believe that are missing - j093 4937 and 3893 962

Hiythankyew

peter henry
Title:
Post by: isle of man on November 04, 2006, 10:10:06 PM
so am i right?
the bearing are starved of oil?




peter henry
Title:
Post by: Bubba on November 05, 2006, 08:51:08 AM
naa dont rekon
Title:
Post by: greggmo on November 05, 2006, 06:34:23 PM
if they where starved of oil the seal wouldnt have started leaking last time surely?
Title:
Post by: isle of man on November 05, 2006, 06:42:47 PM
it's the oil retained by the lower baffle i'm thinking of..........



peter henry
Title:
Post by: Bubba on November 05, 2006, 08:52:14 PM
its all in there as mik can testify
Title:
Post by: isle of man on November 05, 2006, 09:12:50 PM
mmmmmmm........well how about the lift and re-gear was it done at the same time? only i'm thinking the angle for the pinion has moved and thus reducing the oil supply to the bearings??? i had a wrangler (now owned by waggers) that had the axle level plug moved higher to compensate for this............if not that then i'm back to the pumpkin is u/s


still thinking,




peter henry
Title:
Post by: Bubba on November 05, 2006, 09:28:53 PM
lift went on first then almost a year later the regear its only a four popper so only makes as much power as a hoover so that wouldnt damadge the pumkin and there ar know heavy impact marks on it  pity a cj axel could not be fitted  i cant help wonder if the pinion itself is not machined true
Title:
Post by: greggmo on November 05, 2006, 09:29:29 PM
nope. the lift has been on two yaers longer than the regear. the stuff that came out was perfect with good wear pattern. keep thinkin guys.
Title:
Post by: isle of man on November 05, 2006, 09:39:21 PM
well it's possible................but on a earlier thread it was stated that a quality replacement part was used.


still thinking,




peter henry
Title:
Post by: Bubba on November 05, 2006, 09:43:48 PM
i didnt whitle it out of a lump wood if thats what ya thinkin
Title:
Post by: greggmo on November 05, 2006, 09:46:03 PM
:lol: bubba you ass. the parts where all new and they where tomken bearings and propper install kits where user both times.
Title:
Post by: eastryjeep on November 06, 2006, 01:25:41 PM
Really grasping at straws now, but still thinking though!
Would/could siezed or sloppy propshaft splines or an out of balance shaft cause bearing failure like this?
BTW if your bearings are manufactured by Timken then you have a quality part, however Tomken is a make I've never heard of.
Also of note is that when bearings are paired in such close proximity they sometimes need to be a 'matched pair' and are sold as such. They are naturally more expensive, but if it's a matched pair you need that's the only way to go or else this is exactly the kind of problem you'll get.

Still thinking!
Title:
Post by: MK1 on November 06, 2006, 01:55:06 PM
I suspect that because I and O are next to each other then it is a case of fat  fingers. I guess he means timken.
Title:
Post by: greggmo on November 06, 2006, 03:39:34 PM
yeh i mean timken. tomken is a company that make bumpers and stuff. my fingers aint as fat as yours barsey. :lol:
Title:
Post by: eastryjeep on November 07, 2006, 12:24:36 PM
Still thinking!
As this problem started when you re-geared, I still suspect that's where our root cause lies.
How tall did you go on your gearing? It occurred to me that if you have gone right to the limit and now have a lot of unsprung mass in the way of large diameter heavy tyres, heavy rims, bead locks, and very tall gearing all compounded with a motor with plenty of grunt (or any sort of combination) then you may just have reached the extent of the modifications that your front axle will actually take!
Think of it like this.
Through all these tribulations, the rear diff has remained quite happy and the only fundamental difference between the two diffs (please correct me if I'm wrong here) is that the input shaft turns in the opposite direction. So my reasoning is that if the whole drivetrain, after the transfer case, were stressed close to the max. then when you step on the noise pedal the rear pinion gear loads itself up into engagement (as designed in deepest darkest history), whilst the front pinion shaft may be trying to push itself out of engagement, along the shaft axis, releasing the bearing preload and generally knackering the bearings because they are now outside optimal operating parameters.
Follow this link and scroll down to 'Solid Spacers' and see if this rings any bells:

http://www.allprooffroad.com/index.php? ... view&id=20 (http://www.allprooffroad.com/index.php?option=content&task=view&id=20)
Title:
Post by: greggmo on November 07, 2006, 12:56:43 PM
there is no crush sleve in the front end. cos that was what we thought about the back at first. keep em comin.
Title:
Post by: eastryjeep on November 07, 2006, 01:44:57 PM
Try these links then!

http://www.jpmagazine.com/techarticles/ ... g_dana_35/ (http://www.jpmagazine.com/techarticles/16722_building_dana_35/)

http://www.4x4wire.com/tech/pinionangle/ (http://www.4x4wire.com/tech/pinionangle/)

Stopped thinking and started surfing now!
Title: Heh Gregg, John here from the states!!
Post by: HMR-RSQ on November 09, 2006, 12:21:08 AM
Heh do ya have any vibs at mid/hiway speeds? ,
1) possibly the yoke could be loose on the pinion.  
2)Contact the gear manufacture
3)Pinion outta wack!
4)Is this a daily driver?
I used to own www.gotjeepwedo.com (http://www.gotjeepwedo.com) until I got sick(cancer) and I'll try to help where I can.
The gear manufacture will probably replace gear set and install kit. If ya persist. They can afford to do this from time to time.
Good luck HMR-RSQ
Title:
Post by: greggmo on November 09, 2006, 07:21:24 PM
yes mate did have vibes but i think the prop needs a balance. it is now running without the prop until i can get it sorted once and for all. so you think the pinion might be the problem? it is my daily driver but doesn't clock up a great deal of miles.
Title:
Post by: eastryjeep on November 10, 2006, 11:38:30 AM
Tall gearing, moderate speeds and prop whirl caused by an out of balance shaft would do the pinion bearings in for sure!
Title:
Post by: greggmo on November 11, 2006, 12:02:27 AM
i see ya point mate but it ain't done hardly any miles each time and the only time i had vibes was at motorway speeds which i don't do very regularly. i think i will order more bits and have a rebuild again and get the prop in for balancing again and see what happens cos it just still don't make sense. :shock:
Title:
Post by: Dingo on November 11, 2006, 01:27:24 AM
What about getting freewheeling hubs? Save the front prop and locker wearing out, save it for offroading like moi. Not a cure but your bearings might last longer.
Title:
Post by: greggmo on November 11, 2006, 09:25:47 AM
i would love the hub conversion ding but it is bloody expensive. :cry: