VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Pulling the crankshaft gear

I have a 26 engine someone wants the crankshaft gear off of. I got to it w/o any problem but when I went to bolt my gear puller to it I found that I do not have a bolt that would fit the two holes in it. I have 5/16 and 3/8 bolts. The 5/16 is a tad too narrow and the 3/8 a tad to wide. That leaves either an 11/32 or a metric. I seriously doubt metric bolts were used on any 1926 American made car. I went to all the local hardware stores and the NAPA Jobber. None had any 11/32 bolts.

Can someone please tell me what size bolt fits that gear?

Thanks in advance.

Bill


On a side note the camshaft gear is made of fiber. When I went to pull it it started to give where the puller grips it. I immediately stopped. I do not envision being able to remove the camshaft gear without ruining it. How is it removed?

The crank gear can be pulled with the two bolts as you described. As I understand the bolts go through your puller without catching anything. Use a washer to give the puller something to grab. One of the two bolts you mention will screw into the two threaded holes in the crank gear.

Cam Gear, STOP BEFORE YOU RUIN GEAR AND CAM. The cam is held in by two bolts reachable through the two holes in the cam gear when properly aligned. When they are removed and all the cam lifters, the gear and cam will be removed as a unit. A press is needed to separate the cam and gear. You must understand the procedure or you will continue to ruin the cam retainer and the cam gear.

Thanks Ray for your quick response. I was unaware the cam gear needed to be pressed off. It can remain in the engine.

I understand how to remove the crank gear. I need to know the size of the bolts as 5/16 is too narrow and 3/8 too large. These two bolts go through the puller and screw into the crank gear.

I guess I don't understand your situation. When you say that 5/16 it too narrow, do you mean it is too small and the threads don't match? The 3/8 is too large, the threads don't match the crank gear? I don't have a gear handy to check but I think the 5/16 is the correct thread and it is the coarse thread.

That is what I mean. A 3/8 bolt will not enter the bolt hole at all. The 5/16 bolt slides in easily and fits in to the point there is no play to speak of. I can feel the threads of the bolt rub the threads of the hole. If it was 1/32 larger I believe it would fit well enough to grip. The bolt holes are clean and the threads are intact and undamaged. This gear almost looks new.

Sounds as though you may be trying a coarse thead bolt in a fine thread hole.

Hi Bill

I have several used gear with W 3/8-16 treads. I have also a new one with 5/16- 22 BSW tread. 5/16 UNC and Withtwort have 18 TPI. I think you have 5/16-22 BSW tread gear.
The gear are made in soft materials so you can cut new treads in 5/16 UNC or 8mm. I think it will work for you.

Go to post #158295 Des 04 2009 and se how you can press of the fiber gear

Not hardly. I may not recognize thread per inch size but I understand the difference between fine and coarse threads. I can usually match threads by sight. I also understand if a bolt slips easily into a hole it is too narrow. If it does not fit at all it is too wide.

BZ,

Several people have suggested drilling it out and retapping it. That may be what I have to do.

It is raining cats and dogs right now so I won't be able to get to it but I am thinking that just for the heck of it making a video showing what I have and how none of it works and then posting that video here.

Until it quits raining though all I am going to do is talk about it.

Bluezone,

For the record to save future confusion, the 5/16-22 thread (with 55º thread angle) is 5/16 BSF. 5/16-18 (with 55 degree thread angle) is 5/16 BSW.

franco

Another good place to try out the PB Blaster and the big hammer! I have a couple of old 28 engines sitting around the shop, maybe I should see if I can get one of them apart.

Hi Franco
You have right.
I miswrite that

I have a 16 lb mall and a 28 year old son to swing it. Will that work?

Why can't you use a bolt that slips through the hole and back it up with washer on the back side and use the puller they would have to be larger washer.

Hi Andy
The are not a space behind the gear wheel to do that.

THANK YOU I was not sure about the space.

Bill, I was thinking that a 3 pounder Howco hammer would be about right, or just tell the guy wanting the gear that the gear isn't coming off, for a while.

It also crossed my mind to get a cuttin' torch and set it free from that engine.

I'll get it. I appreciate everyones help but a 5/16 will not fit regardless of thread count or pitch and a 3/8 won't fit w/o making some alterations. The only way a 5/16 might fit would be if the threads were wider. If I can't find something like that then I'll drill and tap it. That shouldn't be too hard to do with such large pilot holes already there.

Depending on how hard the gear is, the original tapped holes with the worn 5/16 threads can probably be repaired using a couple of 5/16 Helicoils or similar wire wound thread repair inserts together with the oversize tap to suit. This will provide a permanent standard sized repair which can be used any number of times in the future.

Frank

The gear looks like new and the holes are not at all damaged.

I am not communicating my thoughts well apparently. It seems the holes are of a bastard size. They appear to be 11/32.

Hey Bill - I just ran a 3/8-16 tap into my old gear. If you can't get it off, not to worry, as I have a couple more to inspect on my side of the country before I get desperate.

Roger

The only way to get it off will be for me to tap it. That's no big deal. I just have to wait until Monday to get the proper drill bit and tap.

Bill, before I did any drilling I would soak it real good with PB Blaster or motor oil and try running a 3/8 - 16 tab in real slow and easy, It may be that it will go in and then you can use a 3/8 - 16 bolt, without doing any drilling. I wonder if maybe someone hammered on the threads and messed up the starting thread. Just a WAG

You were right. Apparently there was enough of a burr on the starter threads to give the appearance of being smaller than it actually was/is. A 3/8 x 16 tap cured that. The gear pulled off w/o a hitch.

Hey, I never said I was smart.

Thanks for the help everyone

Happy you got the gear off and welcome to the real world, we all do it. The result is what counts!