88 Suburban Slip Yoke Leak

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I have an 88 Suburban, 90k miles, that seems to be leaking ATF through the rear driveshaft slip yoke. I've cleaned it up twice, and both times the ATF appears on the slip yoke before anything else. It pretty
quickly spreads as it slings all over the place and drips back down on the transfer case.
How do I seal the yoke? There appears to be a pressed-in plug in the middle of the yoke. I've got a picture here-
http://spam_me.home.mindspring.com/88sub/88yoke.jpg
How do I fix this?
a) Slather it with JB weld? b) Knock out the plug from inside the yoke and reseal it with RTV? c) Weld it?
While I'm at it, what holds these u-joints in? It looks like a small plastic pin is all that keeps them in the yoke. (See picture). If I drop the drive shaft I'm tempted to do the u-joints and rear seal on the transfer case while I'm at it.
Suggestions?
-RC
R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA
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The welch plug at the end of the yoke may have worked a little loose or even gotten a rust pin hole in it. Just knock it out and put a new one in, a little hardening gasket sealer is used here, not RTV. The u-joints are still original as they are held in by the injected plastic. The replacements will use snap rings. Just press the u-joints out the plastic will break free.
Brian

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Thanks Brian, that's helpful info. I checked my parts book and didn't see a separate plug from the yoke. I'll call the dealer and ask them for one.
-RC
R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA
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R Clarke wrote:

Easiest way to remove these u-joints is to use heat around the cups until the plastic just melts and oozes out. Then just press them out. The new u-joint will have a different way of retaining them...clips on the inside of the yoke.
Ian
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On Sat, 19 Jun 2004 20:52:50 GMT, R Clarke

Follow up-
I called the dealer and asked if they listed the slip yoke plug. No go. I called a tranny service shop and told them my slip yoke was leaking. The first question the guy asked, "Chevy Truck?" How'd he guess? ;-)
The tranny service guy said he would seal it with silicone from the inside. I don't see how he can get it to fill the bottom without fouling the splines.
I pulled the driveshaft this evening and had a look at the slip yoke. Decided against the silicone trick and popped out the u-joints. The previous owner had replaced the rear u-joint but not the front. Go figure.
The plug was peened into the yoke pretty good so there was no way to get it out without some serious grinding. I opted for a bead of JB Weld on the outside after cleaning the yoke up really well.
When I reinstall the driveshaft I'll drain and refill the transfer case. Anyone know where I can get replacement sealing washers for the drain and fill plugs? The parts girl at the dealer swore she'd never seen anything but the tapered thread plugs that have a square drive hole. These plugs are hex head cap screws with a face seal. My parts book shows the plugs correctly, but no washer.
What are the chances the driveshaft will still be balanced after I replace the u-joints? I marked everything so it would go back together the same way.
-RC
R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA
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If you've marked the part orientation prior to assembly you should be just fine. Short of getting the plug out JB Weld will probably work OK. You need to get it really clean and hit it with some 80 grit sand paper to give the JB Weld something to bite on.
Did the plugs have washers? Mine are taper pipe plugs, but it's a 1999. If the plugs have a flat under the head for a washer just take them to a parts store and match up a couple of drain plug washers. I also like to use a wrap of Teflon tape.
HTH
Brian
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Most if not all manufacturers have outlawed the use of teflon tape in hydraulic systems. A stray strand can play hell with a close tolerance valve. Teflon paste is a much better(and safer) choice. H
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I'll buy that, but I wouldn't consider a transfer case a hydraulic system.
Brian
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wrote:

I worked for years on high pressure plumbing that conveyed extremely hazardous materials. I used teflon tape on all tapered threads. Never had a problem. Others did though. Technique made all the difference.
When wrapping the tape it was imporatnt to leave the front threads clear. The tail end of the tape was wrapped away from the leading end of the threads. That way when assembled the shreds of tape would remain captured in the threads.
Disassembly and reassembly required fastidious cleaning of the shredded tape from the threads. My tools of choice were dental picks, wire brusehes and forceps. Anyone who didn't take the time to do it right payed the price of leaks and clogs.
I didn't use the liquid thread sealants because of contamination issues. Purity requirements on some systems were very high and we didn't always have the budget for face sealed components.
Yes the plugs on the '88 Suburban V1500 are straight thread with sealing washers. They look to be bigger than 1/2" (I can fit my middle finger through the hole) so the local parts place might not have a washer that will fit.
-RC
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<snipped> <cut> <rearanged> <spaced> <paragraphed> <edited to my likeing>
====== ======
Re: 88 Suburban Slip Yoke Leak On Tue, Jun 22, 2004, 1:46am (CDT+5) spam snipped-for-privacy@SpamBlocKmindspring.com (RClarke) updated the group with.....
Follow up- I called the dealer and asked if they listed the slip yoke plug. No go.
I called a tranny service shop and told them my slip yoke was leaking. The first question the guy asked, "Chevy Truck?" How'd he guess? ;-) The tranny service guy said he would seal it with silicone from the inside. I don't see how he can get it to fill the bottom without fouling the splines.
I pulled the driveshaft this evening and had a look at the slip yoke. Decided against the silicone trick and popped out the u-joints. The previous owner had replaced the rear u-joint but not the front. Go figure.
The plug was peened into the yoke pretty good so there was no way to get it out without some serious grinding. I opted for a bead of JB Weld on the outside after cleaning the yoke up really well.
When I reinstall the driveshaft I'll drain and refill the transfer case. Anyone know where I can get replacement sealing washers for the drain and fill plugs?
What are the chances the driveshaft will still be balanced after I replace the u-joints?
-RC R.Clarke =============== ===============
You should have listened to the tranny dude. You're going to be redoing that seal job in about 6 weeks or less. Depends on how you use the truck, but more importantly on how often you crawl under it to see if it's still leaking.
Top qualility silicone stops the leak for good, and trust me when I say....that JB Weld is going to start leaking again pretty quickly.
as to the Drain Plug deal.....
Go by that tranny shop you called up and carry the drain plug with you. He'll likely give you a teflon washer or an o-ring to go back on it... NO CHARGE. (something he would have done for free when when he refilled the transfer case after slapping all that silicone in the driveshaft yoke..for about $20..or less)
You could always carry the plug down to a NAPA and get a teflon seal out of their assortmant box...or even the Hardware store.
as to the Balanced Driveshaft........
It should be just as good as before the repair. Unless......you whacked on it too hard and bent it....or dropped a needle bearing.
RECAP ::
When the JB Weld starts leaking, get you some silicone.
Take the Drainplug somewhere and simply match up a teflon sealing ring to it.
You probly bent the driveshaft. (but lets hope not)
The Tranny Guy should have been able to do the entire job for $40-$50.
END OF RECAP
respectfully MarshMonster ~jb weld cracks when vibrated, jerked, slammed,banged, bumped, beat up~ fact..not fiction ========== ==========
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On Wed, 23 Jun 2004 00:03:28 -0500, snipped-for-privacy@webtv.net (Marsh Monster) wrote:

Good call. It started leaking almost immediately. Not much but I can tell it's starting to seep. It's slow enought for now to move this item down the list a bit. There's a bunch of high priority items to get this old Sub trip worthy.
What kind of silicone do they use? I assume it's a two part liquid that will pool at the bottom before it cures.
One of the new u-joints (Neapco Brute Force) is binding after installation. It's the rear u-joint where it's pressed into the drive shaft. The old one came out real easy and the new one went in easy too, until the last few thousandths. I had to crank down on my hand press to get the second c-clip to go in. Driveshaft was clean so it isn't dirt reducing clearance. I'm guessing the u-joint was ground a tad too long. I can still move it by hand but it's stiff. Any guesses how long before it grenades?
-RC
R.Clarke spam snipped-for-privacy@BlocKmindspring.com RTP, NC, USA
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You clean the inside of the yoke with carb cleaner:
Then a good quality starting fluid to take out all the tail solvents. Then use a good light and a long stick. Use Permatex and no substitutes (Clear) silicone.
Get a long 1/4" wooden dowel rod from the hardware store, and put the silicone on the end of the dowel, then spread it at the bottom, around the clean edges and into the splines. But, at the bottom only!
As for the binding U-Joint, hit each ear of the shaft with a hammer, medium force, not a BFH. use a MFH. Then it won't bind anymore. That centers the U-Joint.
Refinish King

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. . . <cut> <snipped> <headered> <modified for impotence> ======= ======= (RClarke) wrote Marsh to say............
It started leaking almost immediately.
(a question) What kind of silicone do they use?
(a remorsefull sigh) One of the new u-joints (Neapco Brute Force) is binding after installation.
(a diagnostic clue) It's the rear u-joint where it's pressed into the drive shaft.
===DIAGNOSIS TIP=== PLEASE READ CAREFULLY
I had to crank down on my hand press to get the second c-clip to go in.
I can still move it by hand but it's stiff.
(another question) Any guesses how long before it grenades?
-RC R.Clarke ==================== ===================== Answers to your questions........
=(concerning silicone)= I don't know what kind "they" use.
=(concerning u-joints & grenades)= I don't know how long it will take.
Answers to the questions you didn't ask........
=(concerning silicone)= I use Mopar ATF exclusively, and if i may add, on a daily basis.
(concerning other methods to stop the leak) Yes...there is another way. You could just pack the yoke full of wheel bearing grease. Works like magic for about 6 months or so. I have known it to work for longer. FACT....not fiction.
(concerning u-joints & grenades) Yes....I would go ahead and pop that sucker back out and get a NEW U-JOINT...... BEFORE that vibration starts driving you crazy try'n to figure out what it is.
Because ....you dropped a needle bearing down in the bottom of the cup....and that's why you had to SMASH THAT SUCKER togeather to get the clip on, the bearing laying at the bottom kept the cap from going all the way on...and now....YOU'VE CRUSHED IT.
RECAP:
(your investment)
JB Weld U-Joint Tranny fluid 3 hours labor
SUGGESTION:
drop it off one morning at the tranny shop and when they get an open rack.....one of the guys will knock the whole job out in about 30 minutes. Then you can pick it up on the way home from work.
AND YOU WILL HAVE A WARRANTY. for around $40.....
And..... always remember.....and never forget....... there are some jobs that just aren't worth doing yourself. It just isn't good econmical sense to spend 3 hours labor to save $20.
but then again..... I've already spent at least $50 on my vegetable garden.....and we're only talking about a couple dozen plants. All for a few tomatos, egg plants, and cucumbers. Wonder what my water bills gonna be like.
respectfully,
MarshMonster ~wonders how much you've spent so far...... saving money......oh well.....gotta get down to the store to get me some bug spray for the garden.
============ ============
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Marsh Monster wrote:

Well, I'll disagree with Marsh on this one. You "may" have gotten a needle bearing sideways, but I doubt that you could get a cup in far enough "with a needle bearing in there" to be able to get the last clip in place. I do plenty of u-joints, and there are more then a few that need to be pressed very tightly to get that last few thousands of an inch clearance to get the retaining clip in. This is "normal". It's also "normal" for the u-joint to be very stiff after you've just installed it. As Refinish King mentioned, (or was it someone else?) just smack the ears of the yoke or shaft a bit and the u-joint will loosen right up.
Ian
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Just an after thought why I used JBWeld. I've used it with 100% success fixing aluminum parts. Cylinder heads, valve cover, cases on motorcycles that have suffered a misaimed hammer or crash damage. I've used it to fill gaps and seal cracks. It has never failed even after years of hot oil and vibration in those applications.
These were not presurized systems. Just hot oil baths or splashes. Is it possible the slip yoke gererates some oil pressure as it moves in and out? A guy at work pointed out that the yoke is cast iron and I was trying to get JBWeld to stick to a well seasoned fry pan, not the same as aluminum. I used carb cleanere, light mineral spirits, and contact cleaner followed by oil-free compressed air to clean the yoke before applying jbweld. Allowed to cure overnight followed by 8 hours under a hot lamp at ~150F. This always worked for me in the past. Adhesion appears to be good. Still a slight seep at the edge of the stuff.
Live and learn.
-RC
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Just as good as they were when the old joints were in:
As long as you didn't pound on one ear so hard, and bend it a bit/
Usually, it's a bit difficult to do that, so you would have had to have one hell of a seized cap, or one heavy handed SOB with a BFH!
I'm sure you didn't bend anything. I've seen garden variety mental deficients, like that Cobra Jet from the other group install U-Joints and not screw up!
I hope this helps?
Refinish King

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On Thu, 24 Jun 2004 20:12:14 -0400, "Refinish King"

That helps plenty. 20 years or so I bent the ears and everything else on a datsun 510 that had seen a terminal dose of salt. Every nut and bolt was a heartbreaker.
-Rick, the former salty dog
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You're comparing Hiroshima bomb metal send backs:
To true blue recycled American scrap. The Datsun eras will bend every time!
Refinish King

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Thanks for everyone's advice. I'm going to pull the driveshaft again after I finish the intake manifold repair. I'll be discussing that one on alt.trucks.chevy
Why do I do it? Not to save time or money. Mainly so I know the job is done right (or wrong). Unless you're Jay Leno, you can't afford to have the job done perfect at shop rates. If I screw something up, despite my best efforts, I usually know it and will do what it takes to make it right. Professionals screw up now and then too. Depending on the screw up and their integrity, they may or may not reveal it to the customer.
About 30yrs ago I took auto mechanics at tech, did tune-ups and repairs for money while I went to college. I've been a shade tree DIYer ever since. It's a rare day that I've taken a car into the shop to let a pro do the job. Maybe twice in the last few decades.
I don't have the experience a long time mechanic will. Skills I have a good bit of due to a "hands-on" career in an industrial development/production environment. For experience I'm taking advantage of y'alls colective net wisdom.
Thanks again, Rick
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R Clarke wrote:

Frankly, the experience of a long time mechanic comes in handy when you are trying to make a living while doing quality work. In your case, if you have any sort of mechanical aptitude, and you are doing the job for yourself....it may take longer, but it will turn out as good as a professional mechanic could do it, quality wise.
Ian
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