Chevy 235 Timing Gears Issue

Hello, I am finally getting around to installing my new camshaft and lifters on my '58 235 but have hit a snag.

I pulled the old crankshaft gear off and installed a new one (by heating it and driving it on till it bottomed out). I had a machine shop heat and press on the new aluminum gear for the camshaft. I checked the gap with a feeler gauge and it is within spec (.004").

I just slid the camshaft in and now the camshaft and crankshaft gears are not sitting flush. From what I can tell the camshaft gear is sitting out about .025" compared to the crankshaft gear.

Pictures of the problem:



Does anyone have any idea why they wouldn't line up?

Thanks

 

Hold a straight edge against the front of the camshaft gear. The hub should be even with the edges. It is hard to tell from your pictures. If the hub extends forward of the sides you have a 250 camshaft gear. They go on but they don't quite work correctly.

 

Just gave this a shot. The hub is perfectly even with the edges. Thanks for the suggestion though!

 

Any else have any ideas? I followed the shop manuals instructions to the letter so I am lost. Is it possible that the crankshaft gear could have gone on too far?

 

In the pictures it looks like the gear is not on straight. one picture shows the cam gear out from the crank gear, the other picture shows it in to far. Also it looks like to much play between the teeth. To me it looks like the gear was put on crooked.

 

do you have excesive crank endplay?could be an over machined crank gear may need brass shim to space out where needed

 

That's what I was thinking. Mark the cam gear 3 or 4 places, rotate it around to see if it gets better or worse. They have to be pressed on squarely and a decent shop will check it for runout.

Like someone else sugested, maybe you have the wrong gear on the cam? If you have the old one, match it up (got measuring tools?) with the new one, also the crank gear just to rule them out.

Bob

 

With the timing marks in the same position, it would seem endplay in the only thing. The timing marks would not be lined up with the cam rotated 180. If there is not excessive cam endplay you should be ok. But, as mentioned above, make sure it is the correct gear set and not for a 230. Depends where you got it, but some of the kids in the chain stores won't know the difference.

I think (it's been a long time) the 235, like the 216, has the bottom two timing cover bolts that are put in from the inside. While you have it apart drill out those 2 holes in the cover and tap the holes in the bearing cap to 5/16, I think it is, so that you don't have to pull the pan to take the cam out next time.

 

The pictures a just a bit deceiving. The camshaft gear is sitting out in both of them. I took those pictures one after another without spinning anything or touching anything. The angle just makes it hard to tell.

The crank endplay is within spec (.007")

I just rotated it a couple times and how much the gear was sticking out didn't change. I just compared the new and old camshaft + crankshaft gears. They are both within +- .002" compared to the old ones.

The cam endplay is .005" so not nearly enough to cause my .025"~ offset. The gear passed 33-Chevy's straight edge test and the dimensions seem to be the same (within reason) of the originals I removed. I got it from my local NAPA that is exclusively knowledgeable older folks.

 

Mooe, what did you end up doing to address this problem? I just put a new timing gear set on a 250 and have the same problem, only opposite--the crank shaft gear sits out about 1/32" from the camshaft gear.