I have a 70' F250 that's been having a timing problem since I bought it. I finally got around to working on it and found that the cam timing gear had skipped and was about 180 degrees from where it should have been. still had the old nylon toothed gear so i decided to upgrade to an edelbrock double roller timing set. got the gears swiched over and noticed that the gears were out of alignment. the crankshaft gear is about .047" forward of the cam gear. Im wondering if there was supposed to be a spacer or something to move the cam gear forward to align. I put the old gears back on to check and they were also misaligned. This is my first time tearing into an engine so any tips or info you guys can give me would be greatly apreciated

 

The nylon timing gear requires a spacer, the replacement gear has the spacer made as part of it, so throw the spacer away.

Upper pic shows the original nylon gear, the spacer is 6265.

 

There was no spacer to begin with and my replacement double roller apparently doesn't have the spacer built in because they do not align. The cam gear sits closer to the engine block than the crank gear does. there is a .047" difference. So do i just need to track down a new spacer or did i get the wrong part?

 

Can you take some pictures of the set up. This seems pretty strange.

 

The factory installed nylon gear required the spacer (C3AZ-6365-A), see parts catalog pic.

The "service part replacement" aluminum gear: C8AZ-6256-A has the spacer made as part of it.

Notice what the parts catalog sez inre C8AZ-6256-A = 6265 spacer NOT USED.

 

If the old gears now are mis-aligned then the new ones are prolly OK. I have two scenarios.
1. There was a spacer there and snuck off without you seeing it when you took the old cam gear off. The little bugger might have fallen down in to the oil pan. Drain the oil and try fishing it out with one of those extend magnets.
2. You gave the new cam gear and cam a few "love taps" a bit to hard and moved the cam in farther than it was.

 

Here are some pics.

This is the original set




the original crank shaft gear is slightly forward of the cam gear




here is the thrust plate just how i found it




the original cam gear and my double roller replacement




here the double roller set is also out of alignment




this is how much of a difference I've got between the two gears

I also went back and checked the cam shaft behind the thrust plate and it appears to be flush. I don't think it has moved in as far as i can tell.

 

I forgot to mention that this isn't the original engine. It had a 360 which got replaced with a re-manufactured 390 back in 85'. The original owner only put about 20000 miles on this engine before parking it due to some timing issue.

 

My suggestion would be to get the spacer and try it. The roller chain probably requires a good alignment. If the chain doesn't hit the cover you're fine.

 

How much cam shaft end play do you have?

 

This is what I am thinking. How much can you pull
the shaft in and out? When you push the new gear
on to the cam I think it moved back a bit. So when
the engine starts the first time now with the new
gear set it will pull itself back into line. I hope this
makes sense to you. Having some play in and out
is not uncommon. And the gears will center again
on the first start. They always have for me.

 

There is very little end play. not enough to make up for the gear alignment. I decided to get a shim for the cam gear. Going to pick it up today. Now i need to realign the cam gear. what is the best way to do that with out damaging anything? It is too stiff to turn by hand

 

Related but irrelevent question.

I was thinking of doing this myself. Is it required, or does it save time to remove the entire front end of the truck?

 

Remove the radiator, fan pulley, water pump and timing cover.

 

sweet, thanks

Couple more Qs.

I see on rockauto that there's a timing cover gasket set with and without a sleeve. Price diff is like $5. What is the sleeve for and how do I know which kit to get?

As for the sprockets, rockauto shows a lot of them. They range in price from $15 to $24 and then jump up to $72 (whch looks like the price where the double rollers begin). Which do you guys get?