What do shot timing gears sound/act like? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

alden · 07-04-2010, 01:42 PM

I'd like to find a diagnosis method without opening up front of the engine

FYI - the engine is a 235 in a 59 Apache.

We attempted to set my dwell/timing this weekend, first by changing out my distributor only to find that the new one wouldn't fire, so we went back to the old one. At various points in time the truck would run but not great, now it won't start at all (I went through the steps laid out by several posters on stovebolt explaining how to put the distributor in). I tried checking the timing by using the ball on the flywheel lined up to the pin but I couldn't see the ball to save my life. Eventually gave up that route and marked the pully for the fan and a spot on the block and tried checking the timing with that. The marks only lined up 1-2 times out of maybe 10 rotations. The most significant result I can get by cranking the engine is a loud single backfire after several seconds of cranking; I know the plugs are getting a spark and the carb is getting fuel. My neighbor is convinced that the timing gears are shot but it seems a bit odd to me that the truck could go from running (albeit roughly) to not even starting in such a short span of time so I'm posing this question to you, any ideas what the problem might be?

Thanks!
Alden

OrrieG · 07-04-2010, 02:45 PM

Crank gear runs the camshaft. Camshaft turns the distributor. If you can turn the crank by hand quite a ways one way, then reverse, without the distributor shaft turning you have slop in the gears. That is why it pops, distributor is firing a plug when the intake or exhaust valve opens assuming it is set at correct timing. Same thing happens on v8s when the chain stretches. If it was a broken tooth is would be skipping a tooth each time until a valve hits a piston because the timing is off. Any yes it can go from running to won't start quickly, been there.

alden · 07-04-2010, 03:35 PM

What's the best way to rotate it backwards? I have been rotating the engine by turning the fan blades by hand but if I try to spin the fan counterclockwise nothing turns except the fan itself.

Thanks!

alden · 07-04-2010, 04:19 PM

One other thing I forgot to mention. I did change the plugs out yesterday as well. I gapped the new ones at .035 (per the service manual), the old ones were really fouled and were anywhere from .015-.025. I didn't think that would cause such a difference but I'm a relative idiot when it comes to working on cars so I figured I should throw that info out there.

dnorris009 · 07-04-2010, 04:30 PM

I'm assuming both distributors have points? Are they set correctly?

alden · 07-04-2010, 05:21 PM

Quote:

Originally Posted by dnorris009

I'm assuming both distributors have points? Are they set correctly?

As far as I know they were set correctly. The advice I was given through stovebolt was to set the point at .016 then to set the timing (roughly) by putting a piece of paper between the points and twist the distributor until it clamped down on it, then back it off until I could just barely slide the paper out without resistance - then when I found that point tighten down the bolt on the distributor. I don't have a gapper that goes as low as .016 so I did have to fudge that slightly (mine only goes to .020 so I made it slightly tighter than that).

kustombrad · 07-04-2010, 06:22 PM

A match book is .016 that will work in a pinch.

OrrieG · 07-04-2010, 08:16 PM

Quote:

Originally Posted by alden

What's the best way to rotate it backwards? I have been rotating the engine by turning the fan blades by hand but if I try to spin the fan counterclockwise nothing turns except the fan itself.

Thanks!

Breaker bar and socket on the crank pulley nut. Engine shouldn't have enough compression to allow the nut to back out. Will probably require an assistant underneath to crank and you to watch the dist.

dwcsr · 07-04-2010, 08:50 PM

Its not the timing gears. you still have something wrong in the points setup and timimg. If the gears were bad then it would have run like crap prior to you changing the dist. Even if the gears were worn they won't jump a tooth and get out of time like a chain can.

go back a pull out the dist and recheck the points gap and see if the capacitor is connected correctly. make sure the wire from the coil to the dist is on the negitive side of the coil and the termianls are good and not frayed. make sure you have good spark, make sure the rotor is in place and the cap is on correctly and the wires are in the proper holes. 1-5-3-6-2-4 is the firing order. I usualy line up the pointer on the flywheel to 0 and look at the rockers on number one to see if they are loose. then point the rotor to the number 1 cylinder and start putting the wires on.

alden · 07-04-2010, 10:27 PM

Quote:

Originally Posted by dwcsr

Its not the timing gears. you still have something wrong in the points setup and timimg. If the gears were bad then it would have run like crap prior to you changing the dist. Even if the gears were worn they won't jump a tooth and get out of time like a chain can.

go back a pull out the dist and recheck the points gap and see if the capacitor is connected correctly. make sure the wire from the coil to the dist is on the negitive side of the coil and the termianls are good and not frayed. make sure you have good spark, make sure the rotor is in place and the cap is on correctly and the wires are in the proper holes. 1-5-3-6-2-4 is the firing order. I usualy line up the pointer on the flywheel to 0 and look at the rockers on number one to see if they are loose. then point the rotor to the number 1 cylinder and start putting the wires on.

If the pointer on the flywheel is at 0, and the rotor is pointed to the connection on the distributor cap that is at the number one cylinder does it matter where the rotor is pointing i.e. if looking at the engine 2 o'clock, 12 o'clock, 6 o'clock etc?

raycow · 07-04-2010, 11:23 PM

Quote:

Originally Posted by alden

If the pointer on the flywheel is at 0, and the rotor is pointed to the connection on the distributor cap that is at the number one cylinder does it matter where the rotor is pointing i.e. if looking at the engine 2 o'clock, 12 o'clock, 6 o'clock etc?

When the pointer is on 0, both #1 and #6 are at TDC. You have to look at the rocker arms to see which cylinder is on compression. See where the rotor is pointing and make that cap contact #1 (or #6 as determined by the rocker arms). It doesn't matter where #1 is on the cap (clock position).

Ray

alden · 07-05-2010, 09:05 AM

raycow - that was the ticket. When I had it running right a couple of days ago I had gone through all the steps including taking the valve cover off and making sure I was on the ball on the #1 cylinder. I must have been on the #6 every time after because I methodically went through the steps this morning taking the valve cover off and ensuring I was on #1 and the truck starts, it's a little weak and not very smooth but it runs which is a huge improvement. I put in the new distributor today with a new set of points and bought a proper feeler gapper so I could make sure i had everything on the points as right as I could possibly get it (i.e. no guesstimates on my part).

pictures of the (mostly) successful install:

A followup question , I had the rear jacked up (for unrelated purposes) and when the truck was running and the gearshifter in neutral the driveshaft and the driver's side rear wheel was spinning very slowly. If I put in the clutch it stopped but just being in neutral it would spin. This doesn't seem normal to me; any thoughts?

Thank you all for your help with this and all my other noobie questions in the past, I love this place

powerdriver 1958 · 07-05-2010, 10:20 AM

Quote:

Originally Posted by alden

A followup question , I had the rear jacked up (for unrelated purposes) and when the truck was running and the gearshifter in neutral the driveshaft and the driver's side rear wheel was spinning very slowly. If I put in the clutch it stopped but just being in neutral it would spin. This doesn't seem normal to me; any thoughts?

Thank you all for your help with this and all my other noobie questions in the past, I love this place

The tire spinning while in neutral is pretty much normal,the thick tranny lube puts a slight drag on things.

raycow · 07-05-2010, 04:07 PM

Alden, I'm glad to hear you got it running. I have long had a soft spot for the 235 and have been working on them since I was a kid. Stovebolts are very forgiving engines and don't ask for much from their owners.

Ray

alden · 07-05-2010, 04:35 PM

Quote:

Originally Posted by raycow

Alden, I'm glad to hear you got it running. I have long had a soft spot for the 235 and have been working on them since I was a kid. Stovebolts are very forgiving engines and don't ask for much from their owners.

Ray

Ray,
That's a good thing because I don't have much to give

alden · 07-11-2010, 12:18 PM

edited - nevermind, got it figured out

07-04-2010, 02:45 PM	#2
OrrieG Registered User Join Date: Jun 2006 Location: Idaho Posts: 8,800	Re: What do shot timing gears sound/act like? Crank gear runs the camshaft. Camshaft turns the distributor. If you can turn the crank by hand quite a ways one way, then reverse, without the distributor shaft turning you have slop in the gears. That is why it pops, distributor is firing a plug when the intake or exhaust valve opens assuming it is set at correct timing. Same thing happens on v8s when the chain stretches. If it was a broken tooth is would be skipping a tooth each time until a valve hits a piston because the timing is off. Any yes it can go from running to won't start quickly, been there. __________________ 1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project Last edited by OrrieG; 07-04-2010 at 02:47 PM.

07-04-2010, 03:35 PM	#3
alden Registered User Join Date: Jan 2009 Location: pomfret, md Posts: 163	Re: What do shot timing gears sound/act like? What's the best way to rotate it backwards? I have been rotating the engine by turning the fan blades by hand but if I try to spin the fan counterclockwise nothing turns except the fan itself. Thanks!

07-04-2010, 04:19 PM	#4
alden Registered User Join Date: Jan 2009 Location: pomfret, md Posts: 163	Re: What do shot timing gears sound/act like? One other thing I forgot to mention. I did change the plugs out yesterday as well. I gapped the new ones at .035 (per the service manual), the old ones were really fouled and were anywhere from .015-.025. I didn't think that would cause such a difference but I'm a relative idiot when it comes to working on cars so I figured I should throw that info out there.

07-04-2010, 04:30 PM	#5
dnorris009 Registered User Join Date: Mar 2010 Location: Canton Ohio Posts: 109	Re: What do shot timing gears sound/act like? I'm assuming both distributors have points? Are they set correctly?

07-04-2010, 06:22 PM	#7
kustombrad Registered User Join Date: Nov 2008 Location: So. Cal. Posts: 452	Re: What do shot timing gears sound/act like? A match book is .016 that will work in a pinch. __________________ It's all about the stance, baby! http://67-72chevytrucks.com/vboard/s...d.php?t=320546

07-04-2010, 01:42 PM	#1
alden Registered User Join Date: Jan 2009 Location: pomfret, md Posts: 163	What do shot timing gears sound/act like? I'd like to find a diagnosis method without opening up front of the engine FYI - the engine is a 235 in a 59 Apache. We attempted to set my dwell/timing this weekend, first by changing out my distributor only to find that the new one wouldn't fire, so we went back to the old one. At various points in time the truck would run but not great, now it won't start at all (I went through the steps laid out by several posters on stovebolt explaining how to put the distributor in). I tried checking the timing by using the ball on the flywheel lined up to the pin but I couldn't see the ball to save my life. Eventually gave up that route and marked the pully for the fan and a spot on the block and tried checking the timing with that. The marks only lined up 1-2 times out of maybe 10 rotations. The most significant result I can get by cranking the engine is a loud single backfire after several seconds of cranking; I know the plugs are getting a spark and the carb is getting fuel. My neighbor is convinced that the timing gears are shot but it seems a bit odd to me that the truck could go from running (albeit roughly) to not even starting in such a short span of time so I'm posing this question to you, any ideas what the problem might be? Thanks! Alden Last edited by alden; 07-04-2010 at 01:42 PM.

07-04-2010, 08:50 PM	#9
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: What do shot timing gears sound/act like? Its not the timing gears. you still have something wrong in the points setup and timimg. If the gears were bad then it would have run like crap prior to you changing the dist. Even if the gears were worn they won't jump a tooth and get out of time like a chain can. go back a pull out the dist and recheck the points gap and see if the capacitor is connected correctly. make sure the wire from the coil to the dist is on the negitive side of the coil and the termianls are good and not frayed. make sure you have good spark, make sure the rotor is in place and the cap is on correctly and the wires are in the proper holes. 1-5-3-6-2-4 is the firing order. I usualy line up the pointer on the flywheel to 0 and look at the rockers on number one to see if they are loose. then point the rotor to the number 1 cylinder and start putting the wires on.

07-05-2010, 09:05 AM	#12
alden Registered User Join Date: Jan 2009 Location: pomfret, md Posts: 163	Re: What do shot timing gears sound/act like? raycow - that was the ticket. When I had it running right a couple of days ago I had gone through all the steps including taking the valve cover off and making sure I was on the ball on the #1 cylinder. I must have been on the #6 every time after because I methodically went through the steps this morning taking the valve cover off and ensuring I was on #1 and the truck starts, it's a little weak and not very smooth but it runs which is a huge improvement. I put in the new distributor today with a new set of points and bought a proper feeler gapper so I could make sure i had everything on the points as right as I could possibly get it (i.e. no guesstimates on my part). pictures of the (mostly) successful install: A followup question , I had the rear jacked up (for unrelated purposes) and when the truck was running and the gearshifter in neutral the driveshaft and the driver's side rear wheel was spinning very slowly. If I put in the clutch it stopped but just being in neutral it would spin. This doesn't seem normal to me; any thoughts? Thank you all for your help with this and all my other noobie questions in the past, I love this place Last edited by alden; 07-05-2010 at 09:19 AM.

07-05-2010, 04:07 PM	#14
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: What do shot timing gears sound/act like? Alden, I'm glad to hear you got it running. I have long had a soft spot for the 235 and have been working on them since I was a kid. Stovebolts are very forgiving engines and don't ask for much from their owners. Ray

07-11-2010, 12:18 PM	#16
alden Registered User Join Date: Jan 2009 Location: pomfret, md Posts: 163	Re: What do shot timing gears sound/act like? edited - nevermind, got it figured out Last edited by alden; 07-11-2010 at 01:31 PM.



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