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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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| | | | Joined: Jun 2005 Posts: 481 'Bolter | | 'Bolter Joined: Jun 2005 Posts: 481 | Three-speed on the column. 1958. At random this transmission will jump out of third gear. Why is this happening? No warning. | | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | There are a number of reasons for a transmission to jump out of gear. Shift linkage adjustment, bad bearings, or transmission to engine alignment. Here is my blog post on this problem
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: May 2015 Posts: 11,120 Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums | | Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums Joined: May 2015 Posts: 11,120 | A worn pilot bearing in the flywheel would to it as well. If the input shaft is misaligned because the clutch disk is off center, the gear will "walk" out of engagement.
Kevin 1951 Chevy 3100 work truckFollow this saga in Project JournalPhotos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together. | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | The front bearings on the cluster gear can also cause it to fall out of gear as well as poppet balls and springs on the shift rails.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Feb 2000 Posts: 90 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 90 | My brother had a 1950 1/2 ton with a 235 that used to pop out of 3rd gear under a load. He simply installed an eye bolt thru the floor under the shift lever with an old bicycle inner tube attached. When cruising, he slipped the free end of the inner tube over the shift knob and he had what he named a "Tennessee overdrive". Crude, but it worked. Now my tranny has acquired this terrible trait. My transmission has not had anything done to it since Saginaw. I thought I would try Royal Purple transmission oil, but it did not remedy this condition. In fact, all it did was make a rather pretty, but expensive puddle in my garage. Any ideas as to the cost for an overhaul? | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Trans' are pretty simple, easy to overhaul, lots of px on the 'net, be a good experience to do oneself. We all have to learn sometime.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jul 2018 Posts: 279 'Bolter | | 'Bolter Joined: Jul 2018 Posts: 279 |
~Charley 1954 Chevy 3100 with 235“Bud”Follow along in the DITY1963 Chevy half ton stepside short box 230 1954 GMC 3 ton 302 And several more Chevy camper and work trucks 1979 1987 1996 | | | | | Joined: Mar 2007 Posts: 3,433 Crusty Old Sarge | | Crusty Old Sarge Joined: Mar 2007 Posts: 3,433 | I recently rebuilt the NV4500 in my 93' K1500, it was fairly complex but doable, a Saginaw 3 speed can't be that difficult to go through.
~ Craig 1958 Viking 4400"The Book of Thor"Read the story in the DITY1960 Chevrolet C10"A Family Heirloom"Follow the story in the DITY Gallery'59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting) If you don't like driving yourTruck, you won't drive yourTruck..| Living life in the SLOW lane | | |
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