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Discussion Starter #1
i got an 04 sierra 1500 SCSB 94K 4.8l, 4l60e, vette servo, BB autocal tuned, 4:11, and stock 16's w/ 255-60. anyways, comin home from work yesterday, noticed the tranny was actin funny. got home and sure enough, oil ALL OVER the truck! the tailshaft seal had fallen out, and was just setting on the yoke, in turn dumping 3+ qts ATF.
i fixed it by just tapping in the existing seal. and topping off w/ atf dex 4 full syn. the last time i screwed with this, was back in Nov, and things have been fine until yesterday.
now my question to the forum is, how the hell can a tailshaft seal just fall out??
since i fixed it, it doesnt appear to be leaking, or working its way back out, so im just gonna keep an eye on it.
anything is appreciated!! TIA
 

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Get a new seal and when you go to install the new one. clean the surface on the output shaft side of tranny where seal seats. Put some of the good adhesive silicon(Permatex black i know Napa has it). install the new seal, and check and correct fluid level if needed.
 

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Discussion Starter #3
thats actually waht my g/f just talked me into (not the silicon tho) thx for the quick advice bro!! this really bother the shit out of me, i hope its just that simple. ill keep this updated!
 

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The tailshaft seals are cheaper at the dealer when you do replace it, and I second Osiris94ej said about using the pematex black. It works great.
 

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Discussion Starter #5
so i went ahead and got a new seal at napa, and some ofthat 3m super adhesive, recommended by the dude. so far so good, will keep this current, ive never seen or heard of this before, everyone i tell, looks baffled, and cant believe me.
thanks for the tips!
 

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Discussion Starter #6
so after a few weeks, i thought the seal was fine...then the other day driving home on the highway, all the sudden, my speedometer goes nuts, bouncing all over the board, ABS light flashing, gnarley vibration throughout the truck. so i limp the truck home, and come to find out, the seal definately came out again, but along with it, came a bushing from the tailshaft of the trans(causing the vibration). so i get the bushing slid back into place, and the seal tapped back in. top off the trans fluid, and go for a drive. everything is fine!
next day hop on the highway, accelerate to 75, and bam! it does it all over again! WTF! im trippin by now. limp it home, and same thing, bushing and seal both came out again.

anyone have any suggestions?? im thinking of a clamp on the tailshaft of the trans, to hold the seal in the tailshaft. i already plan on replacing the seal, but im not convinced the 3m adhesive works at all for the scenerio.

sorry for the novel
anything would be great!
TIA
 

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Discussion Starter #8
now thats what im not sure about. none of this shit started until the seal came out, and its all fine until it does come out, and that bushing follows. anyone else have a suggestion??
TIA
 

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Call and ask dealer or transmission shop. I've never seen this. New to me. But again its 1 and a thousand I see a 2wd.

Sent from my ADR6300 using Tapatalk
 

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JUGS Racing
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Yea I would stop driving it at this point. Could be manufacturer defect in the trans causing the bushing to pop out. The bushing is whats pushing the seal out.
 

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i think that is a sprag at the end. I'm not sure. I WOULD NOT drive it anymore. Kudos to your gal for knowing about cars. My wife can't find the air cleaner in her accord :(

Mr. 960
 

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Discussion Starter #14
got to the root of this biatch!
the cause is the tailshaft housing bushing.
apparantly, the 4l60e tailshaft housing bushing gets worn, and eventually fails. mine spun for a few weeks, pushing the seal out, and eventually the bushing came with it.
had it all fixed this week, new tailshaft housing with "an updated" design from gm. slipyoke, driveline rebalance, full trans service, and some other goodies.
after 1200 bucks, ol betsy is up and gruntn' again, finally!
so if any of you guys have a similar problem as i had, stop immediately, and check that tailshaft!

thanks to you all who put in their .02, i really appreciate the help!
 

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Discussion Starter #15
so here i am, 2 months down the road, and the tailshaft seal dumped again!
now their saying the root cause is my driveline too short. anyone ever hear of this? my mechanic is claiming-of the total surface area of the splined part of the slipyoke, 50% or more of that slipyoke has to be "engaged" with the output shaft at ride height. apparantly im less than that, causing the issue. he also says that because i put a 2'' drop shackle in there, that caused it. after i talk with him a bit, even with the stock shackles in there, itd still be too short!
so here i am, going to pay 800 bucks for a new, bolt in ready, custom driveshaft to hopefully fix this issue.

sorry for the novel, but has anyone EVER see this?? anywhere?? not just with gm's? im almost thinking its my tune? but not sure, i drive it by all means, just not like a grandma.
any help is appreciated
 

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kissin hands shakin babie
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the tune would have nothing to do with this. i think that the output shaft is worn out, causing the new bushing to be loose.
 

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If i was going to buy a new shaft it would be a two peice not one.
 

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AllOffTopic.com FTW!
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$800 for a shaft? Ouch. Worst case scenario I'd get one too long from a junkyard and have it shortened at a driveshaft shop, total investment under $300.

"50% or more of that slipyoke has to be "engaged" with the output shaft at ride height" agrees with what I've learned before. In fact, that is a generous number from what I learned. The shaft shop thought my Buick's slip yoke should be almost fully engaged, leaving only 1/4" of inward travel available (and that's the way it came from the factory with the original transmission). I guess if the end is slightly flared to help fit tightly (is it?), it could yank the seal out when you go over bumps.
 

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Discussion Starter #19
all the above has been considered. getting a scrap shaft and shortening would be the ideal route, but the new shaft is a new shaft, guaranteed, so it would basically eliminate it as a culprit.
im agreeing with GINGER.. i seriously think the trans has a bearing, or shaft wear, causing it. the shop imo is trying to throw money at it without investigating further.
thanks for the tips guys. im going to hit up some more shops and see what they have to say about it.
 
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