Author Topic: transfer case output shaft failure? (Read 14940 times)

peacesells · « **on:** Apr 01, 2009, 10:09:10 AM »

who here has broken one?

Im not TOO worried about as long as im running stock tcase mounts, but I have a few friends that have snapped em.

This summer im going to a flatbelly w/turbo trans and 23spline ultimates and im thinkin a long output shaft

KYOTA · « **Reply #1 on:** Apr 01, 2009, 10:20:11 AM »

these are going in mine
http://www.marlincrawler.com/transfer-case/parts-upgrade/30-spline-transfer-case-output-shaft

boggerunner · « **Reply #2 on:** Apr 01, 2009, 10:30:25 AM »

i broke one last summer, and went with a bobby long
my buddy broke one last weekend and his long output is on the way

BigMike · « **Reply #3 on:** Apr 01, 2009, 03:13:57 PM »

Just remember the Longfield HD Output shaft is only designed for low speed, definitely off road use ONLY

boggerunner · « **Reply #4 on:** Apr 01, 2009, 06:20:04 PM »

both of our rigs are trailer queens

peacesells · « **Reply #5 on:** Apr 01, 2009, 08:01:21 PM »

mine is a trailer queen as well. whats the difference? the oiling holes?

I would like to go with the marlin setup, but im strapped for cash. Especially since im out of a job as of today.

boggerunner · « **Reply #6 on:** Apr 01, 2009, 10:39:45 PM »

id love to have the marlin one too, but im on a budget since i was laid off a few months ago
and the marlin one is rifle drilled for better oiling, and the long one has no oiling hole at all.

BigMike · « **Reply #7 on:** Apr 02, 2009, 03:18:07 AM »

Yes, the no oiling issue. I don't know how the low speed cage bearing is every getting oiled!! From a mechanics of materials stand point, rifle drilling increases the strength of a shaft. I don't know why they omitted it.

We are working on getting the price down. We currently only have a very limited quantity on hand, so the price reflects a demand rather than a supply. Stay tuned to the announcements forum for updates

peacesells · « **Reply #8 on:** Apr 02, 2009, 01:03:54 PM »

Quote from: BigMike on Apr 02, 2009, 03:18:07 AM

We are working on getting the price down. We currently only have a very limited quantity on hand, so the price reflects a demand rather than a supply. Stay tuned to the announcements forum for updates

Ill definately watch for it. its likely going to be mid to late summer before the cash is there anyways.

kiyul4130 · « **Reply #9 on:** Apr 02, 2009, 11:30:29 PM »

i broke mine last year less then an hour into the rubicon for the round-up. it was a bummer. i think i twisted it at the hammers a few months earlier then finished it off at the rubicon. i also went from 4.88 diff gears to 4.10s so that didnt help any.

COToy91 · « **Reply #10 on:** Apr 02, 2009, 11:54:45 PM »

Quote from: BigMike on Apr 02, 2009, 03:18:07 AM

Yes, the no oiling issue. I don't know how the low speed cage bearing is every getting oiled!! From a mechanics of materials stand point, rifle drilling increases the strength of a shaft. I don't know why they omitted it.

We are working on getting the price down. We currently only have a very limited quantity on hand, so the price reflects a demand rather than a supply. Stay tuned to the announcements forum for updates

Theirs looks identical to stock to me, just different material 4340.....
I know so many people that run this and have had ZERO bearing failures or issues. If you guys can sell you kit for less than $220, I think he will out sell easily

kiyul4130 · « **Reply #11 on:** Apr 03, 2009, 12:08:46 AM »

theres no way they could or it will ever sell for less than $220. look how many more parts are having to be made. its a custom roller bearing, needle bearing, tail housing, oil seal, gear, and flange. not just a chromo'd factory replacement. if it drops in price i dont see it getting lower $400. all in all, once you buy it, your DONE and never have to worry again about inputs or outputs. THEN what becomes the weak link is the teeth like r/p gears. its always something......

boggerunner · « **Reply #12 on:** Apr 03, 2009, 06:28:06 PM »

here is mine from last summer in moab

boggerunner · « **Reply #13 on:** Apr 03, 2009, 06:33:54 PM »

and this is erics (birfailed) from last weekend

peacesells · « **Reply #14 on:** Apr 03, 2009, 07:18:20 PM »

DAMN! put a little twist in the spline I see..

Birfailed · « **Reply #15 on:** Apr 04, 2009, 11:40:32 AM »

Hell yes

As soon as I went one ton u-joints have been blowin left and right and now the output. Gotta bobby long in the cases now. We'll see what happens next

Birfailed · « **Reply #16 on:** Apr 10, 2009, 03:30:28 AM »

this thread kinda died, I don't think many people are breaking the stock outputs alot...

Volcom · « **Reply #17 on:** Apr 10, 2009, 09:18:28 AM »

I was planning on running the Longfield output but didn't know about they were only designed for a trail truck. Mine still sees some street. Guess I'll run the stock output for now until I break something and then figure out what to do next.

COToy91 · « **Reply #18 on:** Apr 10, 2009, 10:24:12 AM »

Quote from: Volcom on Apr 10, 2009, 09:18:28 AM

I was planning on running the Longfield output but didn't know about they were only designed for a trail truck. Mine still sees some street. Guess I'll run the stock output for now until I break something and then figure out what to do next.

I would call and ask, I have never heard from anyone else that it is not just a copy of the stock output. Just because it isnt "rifle drilled" doesnt mean it wont oil the same as stock

TacoRunner · « **Reply #19 on:** Apr 10, 2009, 12:15:57 PM »

Quote from: kiyul4130 on Apr 02, 2009, 11:30:29 PM

i broke mine last year less then an hour into the rubicon for the round-up. it was a bummer. i think i twisted it at the hammers a few months earlier then finished it off at the rubicon. i also went from 4.88 diff gears to 4.10s so that didnt help any.

what were you doing, I mean, how hard were you wheeling to break it? Was is something simple or more like backdoor?

Birfailed · « **Reply #20 on:** Apr 10, 2009, 12:20:12 PM »

in my case I had the truck all bound up, i guess it was bound up kinda bad? but it didn't feel like it took alot, let the clutch out, motor groaned down and *snap*, thats the sound of a bad day

peacesells · « **Reply #21 on:** Apr 26, 2009, 10:33:25 PM »

Quote from: Birfailed on Apr 10, 2009, 12:20:12 PM

in my case I had the truck all bound up, i guess it was bound up kinda bad? but it didn't feel like it took alot, let the clutch out, motor groaned down and *snap*, thats the sound of a bad day

what motor/trans mount setup are you running?

It seems like people with the fror style rigid mount crossmembers break a lot of outputs. It doesnt seem to be a big problem unless youre running 37 or bigger tires and the output shaft is next in line on the weak link list.
I know the hub studs are the next weak link after you get longs/hub gears, then when you get drive flanges/arp studs its the output shaft.

boggerunner · « **Reply #22 on:** Apr 27, 2009, 12:18:27 PM »

he has a 22re/w56/dual with 4.7's with 1 ton axles on 38.5's

Volcom · « **Reply #23 on:** Apr 27, 2009, 03:05:22 PM »

Quote from: boggerunner on Apr 27, 2009, 12:18:27 PM

he has a 22re/w56/dual with 4.7's with 1 ton axles on 38.5's

Yup, output will be the weak spot on that setup

BigMike · « **Reply #24 on:** Apr 29, 2009, 10:52:21 AM »

Quote from: COToy91 on Apr 10, 2009, 10:24:12 AM

I would call and ask, I have never heard from anyone else that it is not just a copy of the stock output. Just because it isnt "rifle drilled" doesnt mean it wont oil the same as stock

Ok, the Transfer case only has one oil pump, and it's sole duty is to pressurize the outputshaft with oil. Once the oil is inside the output shaft, it only has one direction to go and that is to the front of the shaft where the low speed gear cage bearing is. Without this, the cage bearing is a sitting duck high above the oil level in the transfer case with no means of lubrication. Bobby Long is very fortunate that in high range torque is not transferred through the reduction gears, and that is why they are not an immediate failure.... yet.

But anyone cruising around in low range with a Bobby Long output shaft is risking burning out the low speed cage bearing in the transfer case. Toyota went through a lot of development putting that oil pump system with the two oil splash trays and the oil pump seal for a very, very good reason.

Therefore, it cannot possibly oil "the same as stock" because you have eliminated the oiling system. You might as well remove the entire oil pump and then go on a road trip. Have fun!

BigMike

TacoRunner · « **Reply #25 on:** Apr 29, 2009, 11:02:30 AM »

So Mike, what is the next week spot in the drive line, if you have a Marlin 30 Spline output? Im guessing it's the 3rd member.

COToy91 · « **Reply #26 on:** Apr 29, 2009, 01:27:07 PM »

Quote from: BigMike on Apr 29, 2009, 10:52:21 AM

Ok, the Transfer case only has one oil pump, and it's sole duty is to pressurize the outputshaft with oil. Once the oil is inside the output shaft, it only has one direction to go and that is to the front of the shaft where the low speed gear cage bearing is. Without this, the cage bearing is a sitting duck high above the oil level in the transfer case with no means of lubrication. Bobby Long is very fortunate that in high range torque is not transferred through the reduction gears, and that is why they are not an immediate failure.... yet.

But anyone cruising around in low range with a Bobby Long output shaft is risking burning out the low speed cage bearing in the transfer case. Toyota went through a lot of development putting that oil pump system with the two oil splash trays and the oil pump seal for a very, very good reason.

Therefore, it cannot possibly oil "the same as stock" because you have eliminated the oiling system. You might as well remove the entire oil pump and then go on a road trip. Have fun!

BigMike

Further explanation of why putting longs output in completely eliminates the oil pump....

Ramrod · « **Reply #27 on:** Apr 29, 2009, 01:51:51 PM »

ive got about 1000 street miles and quite a few trail miles in low range on my long output didnt know anything about this supposed oiling issue

BigMike · « **Reply #28 on:** Apr 29, 2009, 02:55:07 PM »

Quote from: COToy91 on Apr 29, 2009, 01:27:07 PM

Further explanation of why putting longs output in completely eliminates the oil pump....

COToy91,

Thank you for asking for more info on this. It has brought more dangerous information to the surface which I believe must be fully understood if you own a Bobby Long output shaft and intend to drive your truck in any gear in any range and at any reasonable speed.

Please consider the following illustration:

I can get a solid works drawing of this when I get home that will be easier to understand.

The Red circled part is the oil pump. This is located in the tail cavity of housing #4. Oil is designed to be caught and transferred into this cavity where it is caught in the grooves of the oil pump and force-feed through two holes and into the center of the output shaft. As more oil is pumped into the output shaft, the oil is displaced down the center hole of the shaft and exists at the following three locations:

1) The Front Output Gear Cage Bearing (circled in green)
2) The Low Speed Gear Cage Bearing (circled in blue)
3) And out the front of the shaft to feed the input pocket bearing (bearing all the way to the lower left of the image)

--If you are in 2WD High Range, then there is no load on the front output gear cage bearing, no load on the low speed gear cage bearing, and the input pocket bearing is locked in a 1:1 ratio with the output shaft, so although there exists a load on the pocket bearing, it is not rotating relative to the output shaft and therefore no heat is being generated.

HOWEVER, because the front drive shaft is not spinning, the front output gears are not spinning, and that means that the front output gear is not moving BUT the output shaft is moving!! So the gear has a rotational speed of zero and the shaft is hauling the mail. Therefore the bearing circled in green is working and generating heat and if you are on the road or *gulp* highway, that bearing is spinning very fast with out any oil.

This bearing (circled in green) is surrounded by a slip fit shift hub and a thrust washer, making it extremely difficult for oil to enter the cage bearing from either side. This is why at that location on the output shaft there are two side ports that are drilled through the output shaft connecting the inner diameter oil supply with the cage bearing. It is critical to that bearing to get oiled and with the Bobby Long Output shaft it is not.

ADDITIONALLY, the low speed gear cage bearing (circled in blue) is also moving because in 2WD high range the shift hub connect the input to the output shaft (1:1) and since the input gear is always turning no matter the range, that means the counter shaft is always turning and therefore the low speed gear is always turning and therefore the output shaft is ALWAYS rotating at a speed of 2.28:1 (or 4.70:1) times faster than largest low range gear there, the low speed gear. So that cage bearing is generating heat all the time.

So driving around in 2WD High Range is the most dangerous thing to do when your transfer case has a Bobby Long Output shaft because you are most likely to travel at higher speeds in 2WD High Range which will starve the front output gear cage bearing from oil as well as starve the low speed gear cage bearing from oil.

--If you are in 4WD High Range, then at least the front output gear is locked by the 4WD shift hub in a 1:1 ratio with the output shaft, but the issue with the low speed gear cage bearing (circled blue) still exists. Of course the added load of the front wheel drive components will put a larger load on the transfer case which would generate even more heat than normal.

--If you are in 4WD Low Range, now the input gear is rotating at a ratio of 2.28:1 (or 4.70:1) relative to the output shaft. Now the pocket bearing is under a large load PLUS it is rotating at a different rate than the output shaft so it will be generating heat. At least there is a slight possibility of oil splashing up into there, but that bearing is really doing a lot of work in low range and it is very small and I feel it is critical to oil it. That is why Toyota put it directly in the mouth of the output shaft where the oil supply is! The only saving grace here is that in 4WD low range we are not likely to travel at speeds of over 40 mph and certainly not for an extended amount of time. So this is probably the best situation because you are most unlikely to travel in low range at speeds over 20-25 mph? for a prolonged amount of time so the frictional heat generated will be the lowest in low range than in high range.

--

I am sorry if this is very short and sweet and if I've over looked anything, I am at work and have gotten interrupted 5 or 6 times while writing this and really don't have much time to respond. Please reply back if you require further explanation and I will be able to put up a solidworks drawing of the oil ports on the factory and Marlin Crawler output shafts.

So.. wow, I actually didn't realize the problem was THIS severe until I actually thought about it and spelled it all out.

I will see if I can comment on this more later tonight or tomorrow.

Regards,
BigMike

87pickup · « **Reply #29 on:** Apr 29, 2009, 06:49:51 PM »

I will be doing the Marlin HD output this summer and want to run FROR rear disconnect. An reason why the disconnect wont work with the ouput?

peacesells [OP]

peacesells [OP]

peacesells [OP]

peacesells [OP]

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