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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: BigYellow17 on June 01, 2014, 10:34:46 am

Title: Won't go into gear..... Clutch fork, throwout bearing????
Post by: BigYellow17 on June 01, 2014, 10:34:46 am
Again I have a 1980 3/4 ton four-wheel-drive four speed manual will not go into gear I think it has something to do with my clutch fork or throw out bearing is it possible to adjust the clutch fork without disconnecting the transmission?? Any thoughts and what do you think the r n r time is?
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: BADAZ chevy guy on June 01, 2014, 12:06:50 pm
Hydraulic or solid linkage?
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: bake74 on June 01, 2014, 03:28:43 pm
     1980 should be non-hydraulic unless someone has changed it out.  Have you checked under the truck while someone is pushing in on the clutch to make sure you have movement on all the linkages and the clutch fork ?
     Make sure the clutch fork that the push rod attaches to and pushes is actually pushing, if it is and is moving 1 -2 inches then it is not on the outside of the transmission.  If it is not, then find what is not connected anymore.
     Report back your findings.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: BigYellow17 on June 01, 2014, 03:35:13 pm
Its not hydraulic no master cylinder.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: roundhouse on June 01, 2014, 04:23:32 pm
You try it wih engine running ?
Should go into granny or reverse with engine off if you rock the truck a little while pushing on the shifter

Then you could try to crank it

If its
Been sitting a long time
The clutch disc may be rusted to the flywheel.  Which will break loose if you crank it
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: BigYellow17 on June 01, 2014, 04:37:40 pm
I did try it while running. Wont go into gear. The clutch was replaced about a year before i purchased the truck and was hardly driven. I did replace the throwout bearing due to noise while the clutch was depressed. Now i am having this problem. The vehicle hasnt sat for too long at all so i would rule out the rust. I do have an adjustment on the clutch dont i?
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: dvdswan on June 01, 2014, 07:52:04 pm
have someone look at the linkage while you push the clutch like Bake74 said.  it could be multiple issues or just one.  how's the clustch pedal? does it wobble?  how's the z-bar?  is it loose?  is the linkage adjusted correctly?  also, does it go into gear with the truck off?  on my 76 Blazer one of the shifter pins fell into the trans and locked it up in reverse.  pull the shifter and found the pin jambed between gears.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: roundhouse on June 02, 2014, 12:29:23 am

have someone look at the linkage while you push the clutch like Bake74 said.  it could be multiple issues or just one.  how's the clustch pedal? does it wobble?  how's the z-bar?  is it loose?  is the linkage adjusted correctly?  also, does it go into gear with the truck off?  on my 76 Blazer one of the shifter pins fell into the trans and locked it up in reverse.  pull the shifter and found the pin jambed between gears.
good point.    Could be a problem with the shifter

If you have the truck on a slight incline.   Just enough so it will roll by itself  you should be able to get it in granny or reverse by pushing on the shifter while the truck is moving slowly     No need to have it running or mash the clutch pedal

If it won't go in granny or reverse like mentioned above.  It's probably an issue with the shifter 
Something broken

You can pull the shifter pretty easy
Remove the rubber  boot and press down on the round cap surrounding the shifter where it goes into the trans
And turn it 1/4 turn counterclockwise

Once you rotate the cap a little it will pop up a bit.  Then You can pull the shifter stick out
And look at the end and see if something is broken

You may have to use a rag on it to get traction
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: ehjorten on June 02, 2014, 10:28:50 am
Is the shifter moving at all?

If not, it may be the shifter linkage popped out of a slide linkage before it was totally out of gear.  If this happens the detent in the top of the transmission will not allow you to select a different gear.  The shifter will more or less be locked-up!  It can happen when the edges of the shifter get worn down over time selecting gears.

Do as roundhouse says and remove the shifter from the top of the trans.  I am assuming this is a SM465 transmission with internal shift rails.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: bake74 on June 02, 2014, 10:45:29 am
      The biggest problem I see here is there are no answer's to the guesses that have been offered, so there are just more guesses rolling in and the original ones are not being addressed so we can move on with more educated guesses, instead there are more and more guesses being tossed out.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: BigYellow17 on June 02, 2014, 05:19:34 pm
Im going to look through the window of the bellhouseing to see if the fork is still connected. I did have someone looking while depressing clutch the linkage is moving.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: roundhouse on June 03, 2014, 12:47:07 pm
A word of caution if you decide to remove the top cover of the trans

Put it halfway into reverse before you unbolt the cover

Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: Engineer on June 04, 2014, 07:25:42 am
Does your clutch pedal return all the way back without lifting it with your toe?

The way our trucks are designed the big yellow spring on the clutch pedal will hold the clutch pedal in the down position if there is excessive free travel in the clutch linkage. You should have no more than 1.5"~2" of free travel at the pedal. (This translates to about 3/8" at the throwout bearing). The springs in the pressure plate serves to push the pedal back to the over center part where the big yellow spring then pulls the clutch pedal back up to the dash where it normally rests.

If your clutch pedal is returning all the way back to the rest position then your linkage is fine, and your problems are else where. If not, and you have excessive free travel you will need to look for a failure in other areas of the linkage.
Title: Re: Won't go into gear..... Clutch fork, throwout bearing????
Post by: Engineer on June 04, 2014, 07:30:11 am
I should add, if your clutch is adjusted correctly, while at rest, the clutch pedal should be about 2" closer to you than your brake pedal. If they are in line with each other then your clutch is adjusted improperly.