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-   -   Sm318 Transmission Plugs and Transfer case plugs (https://6066gmcclub.com/showthread.php?t=47735)

FetchMeAPepsi August 29th, 2013 07:19 PM

Sm318 Transmission Plugs and Transfer case plugs
 
Does anyone know which of these plugs does what?

I ran into a real nasty problem today on the way home. When I let off the gas it skreeched like rubbing metal any time the transmission wasn't under load.
Push in the clutch = SKREEEEEEEECH!
Get off the gas to slow down = SKREEEEEEECHHH!!!

Push gas to go = Normal

I think I might have squirted water in the transfer case when I was cleaning it with a pressure washer so maybe I just need to change the fluid? If so I don't know which bolt lookin thing is which. :ahhhh:

Transfer case:

http://windypix.com/?dm=B5TQ.jpg





Tranny:

http://windypix.com/?dm=FLW0.jpg



Thanks in advance!

raycow August 30th, 2013 11:30 AM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
The noise with the clutch pushed in worries me more than anything else. Take off the bellhousing bottom cover and have a helper start the engine and push in the clutch while you watch from underneath.

What can you see happening with the release bearing? Is it seized? Does the bearing collar try to spin in the fork? Is there anything else that doesn't look right?

Ray

FetchMeAPepsi August 30th, 2013 04:46 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
Thanks Ray

I don't know what the bearing collar is but I found the bellhousing cover. Right next to it I found this spring lying on the crossmember. Any clue what it might go to? It's heavier than a carb spring. The rust on it makes it look kinda yellow under the camera but it's all rust.

http://windypix.com/?dm=1W1S.jpg





I got the bellhousing cover off and it looks like this, covered in grime and oil of some sort. Click any link for a bigger image:

http://windypix.com/?dm=C7D0.jpg





I'm guessing the collar is the thing this fork holds on to?

http://windypix.com/?dm=KYRO.jpg





I pushed the clutch in with a 2' long board and it moved engine direction to the front of the engine.

http://windypix.com/?dm=2NHS.jpg




It didnt seem to spin or act funny to my untrained eye. Also I didn't hear the skreeching noise either. That seems to only happen when I'm coasting in neutral or when I'm letting the engine slow the truck down while coasting.

:confused:

GMCDAC August 31st, 2013 12:34 AM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
The throwout bearing is the part the fork is holding on to and the collar is that sleeve bolted to the transmission that the throwout bearing is sliding on. Besides the oil leak everything looks pretty good and your pressure plate, clutch disc and flywheel have no oil on them so that is good! Does the oily stuff smell like gear lube? The part of the throwout bearing you can see won't spin unless the bearing is seized up in any position. The bearing part of it you cant see here pushes the pressure plate arms to disengage the clutch when you push the pedal.

That spring looks like a clutch return spring. Your clutch pedal should return clear up including a little pedal free play. If there is no free play the pedal is riding lightly on the throwout bearing causing it to spin all the time, and it should only spin when the pedal starts getting pressed past the freeplay. Usually the spring attaches to the fork outside the bell housing and then will hook to the frame somewhere.

Hopefully one of the V-6 gurus will post a pic of the clutch return spring position for you. I can only show you one on an I-6.

Later---DAC

GMCDAC August 31st, 2013 01:30 AM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
3 Attachment(s)
Just for reference, here are pics of a clutch fork and throwout bearing from a 1964 Chevy pickup. They probably aren't identical but they do the same job as what you are showing.

Later---DAC

raycow August 31st, 2013 06:25 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
Quote:

Originally Posted by FetchMeAPepsi (Post 49950)
I don't know what the bearing collar is but I found the bellhousing cover. Right next to it I found this spring lying on the crossmember. Any clue what it might go to? It's heavier than a carb spring. The rust on it makes it look kinda yellow under the camera but it's all rust.

I got the bellhousing cover off and it looks like this, covered in grime and oil of some sort. Click any link for a bigger image:

I'm guessing the collar is the thing this fork holds on to?

I pushed the clutch in with a 2' long board and it moved engine direction to the front of the engine.

It didnt seem to spin or act funny to my untrained eye. Also I didn't hear the skreeching noise either. That seems to only happen when I'm coasting in neutral or when I'm letting the engine slow the truck down while coasting.

I agree on the fork return spring. This is supposed to pull the bearing away from the pressure plate fingers so it doesn't spin when your foot is off the pedal.
Am I the only one here who thinks the inner end of the clutch fork is too far forward in both the engaged and disengaged positions?

Ray

GMCDAC September 1st, 2013 04:38 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
Yeah, Ray, I agree with that angle, but didnt want to jump to conclusions since I can only look at an I 6 truck. Too short of a throwout bearing?

Later---DAC

BarryGMC September 1st, 2013 06:40 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
http://https://thumbp7-bf1.mail.yaho...=1&w=800&h=800. Here is a picture of the clutch return spring spring there is a hole in the frame and at the outside edge of the arm. The gmc and Chevy are the same.

BarryGMC September 1st, 2013 06:53 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
Well that did not work! Let me see if I can attach it again. The fact that it only happens under a coasting load while moving always leads me to the intermediate shaft in the Rockwell and spicer 18 cases. There is usually a grumbly or rough gear sound under power that is usually assumed to be normal as there is a lot of noise from the engine , and the rest of the drivetrain. Drain the oil and look to see if there is any metal in it.

BarryGMC September 1st, 2013 07:06 PM

Re: Sm318 Transmission Plugs and Transfer case plugs
 
1 Attachment(s)
http://6066gmcclub.com/forum/attachm...1&d=1378058731


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