When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I recently replaced my spark plugs and wires so I decided to just go ahead and replace my cap/rotor too. Upon installation I noticed the new distributor cap was loose, meaning it had movement side to side if I twisted on it.
I thought it was just the clips on my distributor so I bent them to apply more tension on the cap, and still the cap was loose. I then measured the I.D. of both caps and realized the new cap was about 1/16" larger than my old cap.
I go back to Napa and voice my concern, they replace it with another cap and I go home and install it only to have the same issue! I start/drive the truck anyway and it drives great, no apparent issues that I'm aware of.
My old cap fit very tightly and I was expecting the same with a new replacement. Is the loose fit of the new cap any concern, or should I just go with it?
It definitely sounds like cheap parts but I have 3 ford trucks with loose caps that have been just fine for years.. Just drive it a few hundred miles and look under it to make sure you dont have corrosion from a weak button/cap connection and be sure to avoid getting water in that area
I ran into a similar issue recently with a BWD cap adapter that I bought from O'Reilly's.
The adapter was loose/sloppy took it back and looked at another new in box adapter.
Same issue, out of spec parts. I ended up re-using my old Motorcraft adapter until I can
find one that fits correctly.
I use the MSD Cap-a-dapt kit with the same issue. Between the distributor flange being slightly loose and the cap- to-adapter surface being slightly loose, I have a good bit of play. Maybe a full degree or two.the spring clips don't hold it down very well either.
Ford changed the V8 dizzy cap and rotor in 1977 (shown as % in pic). Dizzy cap has male ends plus a plastic adapter below that has the clips to retain the cap in place.
Agreed GLR, I run metric and standard lathes every day at a chinese copper plant and they tend to round EVERYTHING up.. Our standard system is by FAR superior for tolerances hence .01M vs .001S