Cam synchro gear roll pin breaking

[Eck]

So I have a flat tappet cam on my 351 that I've converted to EFI using the cam synchro shaft and sensor from an early 2000's 3.2L F150. I have changed the gear from the steel gear to an iron gear so that it will be compatible with my iron cam. I have used a new synchro shaft from the parts store each time and each time, I can press the gear onto the shaft by hand. The OEM part requires a shop press or a big hammer to get the gear off meaning it shouldn't be that easy to take the gears off and back on on the re-man Chinese junk.

For the 3rd time, the roll pin that holds it in place has broken and I lose all oil pressure. I'm not using a high volume oil pump. I feel my best solution would be to get an OEM from a junkyard and swap the iron gear on that so there is less stress and pressure on the roll pin.

Has anyone else had this issue and found a solution? Any other ideas or suggestions on how to solve this?

[Rox Crusher]

You are correct that the sloppy fitting gear is causing the roll pin to break.

I like your resolution plan too.

[Viperwolf1]

Kill 2 birds. You can make more EFI friendly power with a good roller cam.

[Eck]

Kill 2 birds. You can make more EFI friendly power with a good roller cam.

That's the eventual plan but I'd like to get on the road for the next few months first.

[EFI Guy]

I wasn't aware of any 3.2L stuff, and you should be usning a synchro that is pre 99 on yours. Was that a typo?

If not, try a 96-98 Windstar or Taurus with a 3.8.

[Eck]

Yah sorry. The 4.2 liter was in the F150. Per Oreilly, it also cross references to the 96-98 Windstar. So my assumption is those are both one in the same. I'm 99% sure I'll end up finding the Windstar at the junkyard and use that as the donor and swap in the iron gear.

[Viperwolf1]

Just sayin...

eck.jpg

[Digger]

[horseplay]

short term solution before changing to a roller cam get someone to spot weld the gear with a tig welder. Should hold until you make the swap.

[Eck]

I made it to the junkyard today and was able to get the synchro shaft. The press fit on with the OEM is so much better. Hopefully it'll hold for a bit. For what it's worth, the one I pulled from a Windstar wouldn't go all the way in but the one from the F150 did. In fairness, I did not verify the engine that was in the Windstar so not sure if it had the 3.8L in it.

Horseplay- thanks for the suggestion. I was a little impatient and didn't feel like messing with the spot weld. I feel so much better about this OEM fit so I think it'll be better. If it breaks again before I switch to roller cam- I owe you a beer.

And just to prove to you guys I'm serious about changing out cams soon, I picked these bad boys up today...

[Digger]

So I have a flat tappet cam on my 351 that I've converted to EFI using the cam synchro shaft and sensor from an early 2000's 3.2L F150. I have changed the gear from the steel gear to an iron gear so that it will be compatible with my iron cam. I have used a new synchro shaft from the parts store each time and each time, I can press the gear onto the shaft by hand. The OEM part requires a shop press or a big hammer to get the gear off meaning it shouldn't be that easy to take the gears off and back on on the re-man Chinese junk.

For the 3rd time, the roll pin that holds it in place has broken and I lose all oil pressure. I'm not using a high volume oil pump. I feel my best solution would be to get an OEM from a junkyard and swap the iron gear on that so there is less stress and pressure on the roll pin.

Has anyone else had this issue and found a solution? Any other ideas or suggestions on how to solve this?

Are you using the same iron gear every time? Either way, sloppy fit to the shaft (not press fit) will be hard on the roll pin. You're on the right track. I would caution again any welding on an iron gear unless you understand pre/post-heat treat processes necessary to prevent cracking.

[Eck]

So I have a flat tappet cam on my 351 that I've converted to EFI using the cam synchro shaft and sensor from an early 2000's 3.2L F150. I have changed the gear from the steel gear to an iron gear so that it will be compatible with my iron cam. I have used a new synchro shaft from the parts store each time and each time, I can press the gear onto the shaft by hand. The OEM part requires a shop press or a big hammer to get the gear off meaning it shouldn't be that easy to take the gears off and back on on the re-man Chinese junk.

For the 3rd time, the roll pin that holds it in place has broken and I lose all oil pressure. I'm not using a high volume oil pump. I feel my best solution would be to get an OEM from a junkyard and swap the iron gear on that so there is less stress and pressure on the roll pin.

Has anyone else had this issue and found a solution? Any other ideas or suggestions on how to solve this?

Are you using the same iron gear every time? Either way, sloppy fit to the shaft (not press fit) will be hard on the roll pin. You're on the right track. I would caution again any welding on an iron gear unless you understand pre/post-heat treat processes necessary to prevent cracking.

I used a different gear this last time. When I took the steel gear off the Chinese part, it slid right off. Like that's how that POS came. This one for sure pressed on and I'm gonna run it without welding and cross my fingers it lasts until I replace the cam.

[Viperwolf1]

It might not be a bad idea to throw a spare in the glovebox.