I`m preparing to get back to work on my 1953 3100 after almost a years time. Last winter I thought I was ready to test drive after the following work was completed. 1. Installed a used 1951 235 w hydraulic lifters from a car that had a powerglide tranny. . Ran on run stand with good compression. 2. New clutch,pressure plate and u joints. 3. Had original transmission( 4 speed on floor) out of truck and changed fluid . Had cover off transmission to replace cover plate gasket. At this time the gears moved freely and I believed I got the shift linkage back in its original configuration but not 100 % sure. Shift pattern feels normal. Did not remove any gears or disassemble tranny. 4.Replaced stomp starter switch (Had starter removed from engine ) 5. Drained and changed differential fluid. 6. Removed and cleaned gas tank 7.Truck has had 12 volt upgrade with alternator. THE PROBLEM: With the shifter in nuetral I hit the stomp starter and the truck lurched forward ,as if it was in gear. Tried shifting into other gears and start with the clutch depressed and still lurches forward as if the tranny is in gear even though shifter is in neutral position with plenty of slop. I `m unsure of where the issue may be and want to work backward to try and solve the issue. Any thoughts or help appreciated.
It sounds as if the clutch may be locked up, they will do this on occasion , rusting to the flywheel. You may need to break it loose with a pry bar and see if it will release.
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 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
You're dealing with two problems. The trans cover was installed incorrectly, and one of the gears is engaged all the time, regardless of the shifter position. The next problem is that the clutch disc is stuck to the flywheel. Getting the clutch freed up is the easy part- - - -drop the dust cover off the bell housing, have someone hold the clutch pedal down, and use a putty knife to pry the disc away from the flywheel. Then pull the top back off the transmission and get the gears and shift forks aligned in the neutral gate properly. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Okay I removed trans cover, got the galleries for the shift forks aligned and re-bolted then went under the truck to inspect the clutch assembly. With the clutch lever fully depressed I am able to slide a putty knife into the space between the flywheel (newly machined) and disc. So I crossed my fingers jumped in the truck, and hit the starter and NO LURCH. Hooray! I cranked on it a bit got the fuel running and it starts in neutral. Even Better! BUT.... when I depress the clutch its a no go with shifting into gear, like the clutch isn`t engaging enough. I readjusted the clutch throw rod to no avail. I might note that there is not much extra room between the putty knife and flywheel and disc ;it slides in freely but not many thousands extra. From reading past posts I`m wondering about tranny and pilot bushing alignment. New pilot bushing that came with the clutch kit was installed when engine was out. Wondering about where to go next... Transmission removal? Brew pub? or ??
If the clutch is adjusted properly, there should be somewhere between 3/4" and 1" of free pedal movement before you feel the pressure plate springs begin to compress. You should be able to shift the transmission into any gear position with the clutch depressed, and the vehicle should start to move when the clutch pedal is around halfway released. If that doesn't happen, something is assemble incorrectly. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Tranny and pilot bushing alignment won't affect clutch engagement. I would suspect adjustment of the linkage.
If you put it in gear and hit the starter without pushing the clutch pedal in, does the truck move?
There should be a little slop in the pedal before it gets harder to push as it engages the throwout bearing.
Brew pub sounds like a good idea to think it over with a frosty one.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 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.
If the input shaft is stuck tightly in the pilot bushing then the tranny input shaft will be energized when the engine is running. In this scenario, the tranny will shift just fine into all gears IF THE ENGINE IS OFF. With the engine running, the clutch disc will properly disengage from the flywheel but the energized shaft keeps the tranny gears moving. The truck will lurch if the engine is started with the tranny in gear. If the engine is started with the tranny in neutral, then it won’t lurch but you won’t be able to shift into any gear with the engine running.
If the input shaft is stuck tightly in the pilot bushing then the tranny input shaft will be energized when the engine is running. In this scenario, the tranny will shift just fine into all gears IF THE ENGINE IS OFF. With the engine running, the clutch disc will properly disengage from the flywheel but the energized shaft keeps the tranny gears moving. The truck will take lurch if the engine is started with the tranny in gear. If the engine is started with the tranny in neutral, then it won’t lurch but you won’t be able to shift into any gear with the engine running.
He doesn't state if it's a Chev or GMC. The Chev's used a bushing, the GMC's used a bearing.
Thanks all for the help so far. It is a Chevy. Today I removed the tranny cover again and confirmed that the shift forks ARE properly lined up in their galleries. Lugnutz`s scenerio seems likely as the truck does lurch when starting with tranny in gear. So it`s a real possibility that the input shaft is hung up in the pilot bushing. I assume now it`s time to take the whole thing apart and start over by firstly removing the transmission to check things out. Will I need to drain the new mineral oil out first? When I purchased the clutch kit it came with new bushing which if I remember correctly went in without too much trouble. After reading several posts I`m wondering since the motor is a 1952 that had originally had a powerglide tranny and now is hooked up to a four speed that it may require a different size bushing?? Everything seemed to go together properly when I installed the transmission last time but it has been a few months ago....
If memory serves me correctly, the PG transmission did not use a pilot bushing. If the crankshaft was machined for a pilot bushing I believe there are two choices. Make sure you get the right one. Now someone will come along and let me know my memory is shot!
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
A spare pilot bushing is cheap, so buy another one exactly like the one you installed. Once the transmission is out, see if the spare bushing slips easily over the end of the input shaft pilot tip. If not, then you may have your answer there (that the input shaft is binding in the currently installed pilot bushing OR it’s the wrong bushing altogether).
If it were me, I’d then find an old input shaft with the same exact diameter pilot tip and test fit the old shaft in the bushing installed in the crank. There shouldn’t be any slop but you should be able to hand turn the spare shaft. If it’s really snug, use some 150 grit sandpaper in the inside diameter of the bushing to make it a wee bit bigger so there is no binding. Then reinstall the tranny.
Thanks fellas. I will pursue getting that tranny out and figuring out the correct pilot bushing. Unfortunately today I broke my hip in a bicycle accident so it may take me a couple months to get back on track with the truck.. I really do appreciate how hard you all work to help out the newbies and mechanically challenged!
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 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.
Ouch! At least you didn't do it at 65 MPH with a blown rear tire on a Honda Gold Wing like I did few years ago. That one ended up with a separated shoulder, five broken ribs, a chipped vertebra and a left foot held on by two metal splints and 15 screws. Also an epic case of road rash! Now I ride a Harley.
The pilot bushing for an engine originally equipped with a Powerglide has a slightly smaller outside diameter to keep the inner hole from getting too tight on the transmission shaft as it's driven into the crankshaft. That was true on the early V8 engines and I'm pretty sure it also applies to the 235. A professional-level parts store like NAPA should have a listing for the correct bushing. Another option would be to use a chucking reamer a few thousandths larger than the nose of the transmission input shaft and open up the existing bushing for the correct clearance. Another approach to enlarging a tight bushing is to use an engine porting tool called a "cartridge roll" in a variable speed drill motor to carefully enlarge the diameter. The rolls and the mandrels they fit are on Ebay for very reasonable prices. Pilot bushing fitting isn't brain surgery- - - -just don't open one up to the point it's a sloppy fit. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
[img]https://www.stovebolt.com/ubbthread...8249/filename/IMG_20220101_120322255.jpg[/img]Back on my feet and the plot thickens...I have removed the transmission, clutch and the existing pilot bushing . The bushing came out grudgingly with the bread method of extraction. The bushing is worn in an uneven shape inside indicating a poorly aligned trans. shaft . The OD of this bushing measures 1.091 in I ordered two replacement bushings: A Dorman 690034 the one to use with original powerglide to manual conversion for 50 to 52 235`s. this has an OD of 1.060 in .and an ID of .593 in. I slipped this bushing right into the crankshaft hole by hand and it `s not even a snug fit at all. The second bushing is the replacement bushing for the damaged one I extracted, it is National part number PB-656-HD with an ID of .592 and OD of 1.096. Both bushings slide easily over the transmission snout and seem a good easy fit. (NO apparent damage to transmission snout). Perhaps this engine` s crank had been re-machined to fit the common Chevy size bushing. I have eliminated the Dorman 690034 as a possibility as it`s too small for the hole . The national bushing I ordered actually slightly bigger in OD and I had a difficult time originally driving the damaged bushing in (used a socket and dead-blow hammer, so the new one would probably need a shave to fit. I don`t have easy access to a lathe ,but may be able to arrange some work at a machine shop. It`s not brain surgery but it`s beginning to feel like it! Any suggestions?
