I have a 1990 F150 5.0L How do you know if it has a steel gear or cast iron gear on the distributor shaft??

I ordered a complete distributor with a steel gear from O'Reilly Auto parts but after looking around a bit I saw a warning that says

• Cast Iron And Steel Gears Are Not Interchangeable
• Use Of Incorrect Part Number Will Cause Severe Damage To Camshaft Gear And/Or Distributor Gear

I've not pulled my distributor yet so I have no clue which gear it has. I looked at the compatibility chart and my truck is listed for the distributor I ordered..... please enlighten me.


Tony

 

if the '90 is flat tappet, then the OEM gear is cast iron. If it's a roller motor, then it gets steel. My '90 was flat tappet and my '92 was roller.

 

Another way to check what cam you have now is to pull valve cover and look at the wear pattern on the top of the pushrod under the rocker arm. With roller cams, the lifters dont spin in the bores, thus the pushrods dont rotate, allowing for a wear pattern to develop, which is easy to see.

May try using the search function to help.

 

Just checked the O'Reilly website and searched your year, make, and model. Both of the A1 Cardone distributors are cast iron and the one by RPT with the steel gear is 45$ cheaper than the other by RPT with cast iron gear. I would be inclined to check and see if they have the other available. Also if needed, you can swap the gear from either of the 2, but be sure to identify which is which so as not to get them mixed up.

 

The gear depends on the cam you have. The stock gear is cast iron and you need to use that. One word of caution...when you replace a gear it had better be on there perfect or it will eat the gear on the cam (happened to me,I ended up buying a whole new dizzy from MSD so I didn't eat another cam )

 

It the motor is original to that '90 truck it has a flat tappet cam so the distributor needs a cast gear.

 

Well... I thought it was to good to be true. A complete distributor for $80 bucks. I guess I'll send it back and pay the $150 for the other one.

I'm not opposed to changing the gear if it's nothing more than driving out a drift pin. Is the gear pressed on the shaft or just a snug fit?

Thanks for your help.

Tony

 

There is a pin and it is a snug fit. Again, be careful. I wasn't able to detect any bending or run-out of the shaft but it still ate my cam.

 

Back in the "bad ole days" I replaced a lot of GM HEI pickup coils which required the gear to come off. They weren't very tough to deal with. I may try.... with the price difference it may be worth a shot.

Tony