Sm465 assistance.

[Smitch320]

1.)Got a sm465 in a 86 k10 and I got trans fluid dripping from the U-joint? Bushing?


2.) When I let off of the clutch in first gear, it makes a whining noise, I cant feel it, but it just happens in first and occasionall second. Clutch hasn't been looked at since 97, Im thinking It needs resurfacing? or a new clutch kit?

Experts chime in.

 

[87sierra]

for the whinnig noise check the fluid in the trans make sure it is at the right level
also i believe first gear is a spur gear and they tend to whine more than helical gears but are better for transmiting torque
for the leak it might be the rear bearing gasket and retainer

 

[HotRodPC]

Yeah, might be a little low on gear oil and the input shaft bearing is making a little noise.
Sounds like you might be losing some fluid form the rear seal. But wait, you said a K10? 4x4? So it is driping from the Transfer case, or the Trans???

 

[Smitch320]

It appears to be leaking trans fluid from the yoke of the drive shaft. That extends out from the transfer case. I'm thinking real seal. I will take some pictures

 

[Smitch320]

HotRod,

The shaft that exits the transfer case, and meets up with the drive shaft I think has a bad seal.

Thanks for all of the help, I am not the best when it comes to troubleshooting mechanical issues, Im just good at turning the wrench.

 

[HotRodPC]

Yes, that sounds like the rear seal to the tailshaft housing of the Transfer case. So is this fluid RED? or Blackish Gold? Even in the SM465/NP203 Adapter, I do believe it's possible that your gear oil from that trans can leak into the Transfer Case. When this happens, your Tcase overfills and needs to get rid of the fluid somehow.

Someone back me up on that. I know it can happen on the Auto Trans, but not positive on the SM465. Seems it would have to lose an awful lot of gear oil before it could get into the Tcase with that long cone shaped adapter.

 

[87sierra]

yes it would have to lose a pretty good amount of fluid but it can happen on a manual trans

 

[Smitch320]

Gonna take the truck to my mechanic. I think the noise maybe a Throw out or something, the amout of fluid leaking is not alarming, I just want to get it fixed before the trans start to act up.

 

[Smitch320]

What makes me thing the TOB is when I have the clutch pressed, and am accelerating it "whines" but as soon as I engage the clutch completely nothing happens and it is fine.

I wil try and get a clip of the noise now that I have the truck running and moving.

 

[Irishman999]

I am pretty sure there is not even a seal on the back of the transmission into the transfer case adapter, if any oil makes it in there it just drains out of the bottom of the adapter back into the transmission.

I have had 2 of these transmissions and they both whined at low speeds, I suggest Dyna-mat for the floor if it drives you crazy like mine does. The one currently in my truck has all new ball bearings in it and she still whines like the last one.

As far as your sound, its probably the throw out bearing. Try hitting that grease zerk on the bell housing, but I would be planning on a clutch job. If the throw out bearing is spinning on that front bearing cover thing it moves on it leaves grooves all over it and seems to hang up like mine was doing. You can get all the parts to fix it for 300 or less. I did a writeup on it on the whole job in the tech section.

 

[Irishman999]

Here is the link, with pictures.

http://www.gmsquarebody.com/forum/showthread.php?t=2339

Edit: Finding more pictures I have.

Back of the transmission.

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This is the bearing retainer that holds the input shaft bearing in place and doubles as what the throwout bearing rides on. All the ones I had on hand had grooves worn in them from the bearing spinning on the shaft so to play it safe I ordered a new unit for about 30 bucks through www.novak-adapt.com.

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I Went through the same problems as you, I thought I had a junk transmission because of the whining noise so I took it to a seasoned transmission expert and surprisingly there was like zero wear inside to anything. I was even running it low on gear oil for a while and everything looked perfect inside. The bearings I replaced were actually fine, we just replaced them because I had already ordered them through Novak. My uncle drove the wheels off this truck, he completely wore out one motor in 10 years, the SM-465 is very hard to kill unless you fill it with sand or something.

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More pictures and info while I am at it, having a really laid back morning. You can pay a machine shop to re-surface your flywheel just like brake rotors but they might be busy or closed on weekends. I got a brand new flywheel from Napa for about 30 bucks more than what the machine shop was going to charge for their work and had no wait time.

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With all the involved labor with this I suggest not going for a cheap clutch kit. The AC Delco kit I got from Rockauto was not to expensive and its top notch quality. I could have gone with centerforce or something really heavy duty but I dont want a heavy ass clutch pedal like a commercial truck, the pressure plate springs are just about perfect, this clutch can handle plenty of abuse and torque. I have been running it for about a year now and everything feels perfect.

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The AC Delco kit comes with a new pilot bushing, I learned a cool trick for removing the old one out of the crank that involves grease and the pilot tool.

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You will kick yourself in the ass if a month down the road you start dripping oil out of the bellhousing so while its apart do the rear main seal. Your truck being an 87 should be one piece rear so its a piece of cake to change.

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That is whats most likely making all your noise, that was the case with mine. Here is the new one installed on the clutch fork.

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Hope this helps.

 

[Smitch320]

Irish- Thanks so much for the response.

Im about to drop a 350 sb into my truck, so I was planning on a clutch while I was already down there.

My only question is, What do you think the fluid dripping from the yoke is?

 

[Irishman999]

Irish- Thanks so much for the response.

Im about to drop a 350 sb into my truck, so I was planning on a clutch while I was already down there.

My only question is, What do you think the fluid dripping from the yoke is?

I am going to guess its atf out of the transfer case, most likely the rubber seal. The seal is less than ten bucks, all you have to do is get a 7/16s 12 point wrench and take the u-joint straps loose and slide the driveline out of the back of the transfer case and change out the seal.

 

[Smitch320]

Thats what I was thinking, and wanted to hear. Thanks Irishman

 

[Irishman999]

Thats what I was thinking, and wanted to hear. Thanks Irishman

Not a problem, if you run into any snags let me know. Its only been a year since I did mine so its still pretty fresh.