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Mod | | | Forums66 Topics128,188 Posts1,057,220 Members48,465 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: May 2006 Posts: 48 Wrench Fetcher | | Wrench Fetcher Joined: May 2006 Posts: 48 | Fellow bolters.... When driving my GMC 3 ton, I get a small grind before it will go into gear. I took it to my garage and adjusted the clutch and it was ok but the longer I drive the worse the grind gets and it will not down shift no matter what I do except come to a complete stop before shifting. Now I haven't driven a manual since I was 14 on the farm, but none of what is happening seems normal to me. I call around for parts and everyone can get parts but they want numbers....can I get some help with clutch, rearend, tranny parts?? I need axle seals and noone can find a number unless I pull them apart and take them out.
Matt | | | | | Joined: May 2006 Posts: 48 Wrench Fetcher | | Wrench Fetcher Joined: May 2006 Posts: 48 | I just need help with make and model then people can find the numbers and cross them to get the proper part. | | | | | Joined: Jul 2004 Posts: 2,993 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 2,993 | You may need to learn the fine art of double clutching.
To up-shift--step on clutch, shift to neutral, let up the clutch, then step on it again, and shift to the next gear.
To downshift--step on clutch, shift to neutral, let off the clutch and rev the engine, step on clutch, and shift to the lower gear.
It takes practice, but as you get used to your truck and how it acts, you'll be able to run through the gears without making a sound.
Good luck!! | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy naddaclue, what you are describing sounds more like a transmission problem than a clutch one to me. You said you can't downshift no matter what, not even when you double clutch? As for the parts ask us for numbers for specific parts, hopefully we can help. | | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | 3B, I don't see where he said even double clutching won't help on the downshifts. This transmission appears to be the "crash box" which would require the dance described by Rich. Stuart | | | | | Joined: May 2006 Posts: 48 Wrench Fetcher | | Wrench Fetcher Joined: May 2006 Posts: 48 | I did the double clutch and a few times triple clutched it....I just about had the pedal through the floor board. The mechanic that worked on it had the same problems, the more the truck was driven the worse it got. He seems to think that the pressure plate was getting hot and not allowing a disengage. | | | | | Joined: May 2006 Posts: 48 Wrench Fetcher | | Wrench Fetcher Joined: May 2006 Posts: 48 | as far as parts go...I need to be able to find the make and model of my axle. Make and model of my tranny. I don't even know where to look. | | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | naddaclue,
Would it be possible to pull the flywheel cover, crawl under the truck with a good trouble light and with the help of a friend, work the clutch and see what might develop.
Stuart | | | | | Joined: Dec 2005 Posts: 66 New Guy | | New Guy Joined: Dec 2005 Posts: 66 | Does the clutch slip? You might try NAPA for seals, but if you're going to tear it down anyway, you can get the numbers off the old ones. There are co's on the web that specialize in bearings and seals. | | | | | Joined: Jul 2002 Posts: 165 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 165 | Matt, That transmission does not have syncro's, you must double clutch and when up shifting take your time. go slower than normal to change gears. When down shifting you must double clutch, put in neutral, let out clutch and rev up engine then push in clutch and change to next lower gear. This will take practice, this is not like a modern truck. I dout that you need a clutch, just practice. | | | | | Joined: Dec 2003 Posts: 1,144 'Bolter | | 'Bolter Joined: Dec 2003 Posts: 1,144 | agree with the others double clutching requires rpm trans speed and road speed all to be coordinated just takes practice. And each truck will have slightly different sweet spots as well. Bertha will have her own personality | | |
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