Role pin for distributor - setup unclear

You need a large pin or double pin, a common failure is the stock pin sheering off and then you are stuck. Another thing, make sure your gear is the correctly located on the shaft, this is critical and another common mistake.

I'll elaborate on what Chris wrote above: if your distributor gear is too high or too low on the shaft, it will wear out VERY quickly. There's an article on the Ford Performance web site that describes the procedure for setting the height of the gear. Also, the gear must be a press fit on the shaft or the pin(s) will eventually fail.

Finally, the application is more suited to split pins than roll pins, in spite of the fact roll pins usually have greater shear strength than a split pin of similar size. This is because split pins will take an impact and "spring" back without damage. Roll pins, on the other hand, are weakened by an impact.

Double pinning is a good idea, just make sure the splits in the pins are 180 degrees apart and that the inner pin fits tightly inside the outer. A dab of epoxy on the inner pin helps to keep it in place.

Tx team,
ok I understand the hight issue and the end play Test procedure will set up accoring the sticky documention provided by the Team. Gear fits VERY tight on the shaft - refrigerate and heating procedure I guess.
Got now the difference - was a lack of my English - between ROLL PIN and SPLIT PIN.
Will definatley use a ROLL Pin.
I was just wondering about 2 pins vs one pin.

Now the next issue:...there are at least 2 models out there googleing Roll pin (see picture). The left one is EASY to get in Europe as DIN Standard vs the right one is difficult, looks more like a US standard (??).
Can I use the European model? I might do 2 then..

TX for advise..

Matthias

where are the dual roll pins for sale?

I cannot find them , prever Summit
Thank
Simon

Simon,

This is the style to avoid

This is what you want to do

I am not aware of roll pins being sold as a matched double pin set. I think you will have to determine your larger size and then find a small size that will fit within it. You will wind up buying two pins similar to these

Wooow,

like this as this in European Standard! Easy to find & buy!!

well yes Larry (right?) we need to find the match..stay tuned!

Matthias

Matthias

I am well familiar with this topic. Nobody that I know has ever snapped a standard Ford oil pump drive shaft. Your Pantera's engine does not need a heavy duty oil pump drive shaft. However when owners install the heavy duty shaft, the roll pin shears. It is the use of the aftermarket parts wherein the troubles arise.

My advice is to use standard Ford parts. A Ford distributor, a Ford distributor gear held in place by a standard Ford single roll pin (which has been described above as a split pin), a standard size Ford oil pump drive shaft, a standard volume & standard pressure oil pump. Make sure the distributor gear fits tightly upon the distributor shaft, to the extent that it must be pressed onto the shaft. And make sure the gear is installed on the shaft at the proper dimension. Disassemble the oil pump, de-burr it, clean it thoroughly, lubricate it, reassemble it using thread locker on the fasteners. This assembly will not fail, it will perform its job as it was designed to do. These parts are easy to find. Hundreds of millions of Fords have operated for hundreds of thousands of miles each using these parts without leaving a single owner stranded once.

This king has no clothes.

quote:

This king has no clothes.

George -

The emperor is not supposed to be the one to admit that!

It lets the wind out of all of our sails!




Thanks for all the guidance. I have always felt it to be highly useful.

Rocky (Chuck)

I think George is so right about this.

I had never heard so much drama with distributor roll pins until I joined this forum.

In Australia where the Cleveland engine was as ubiquitous as the small block Chevy is in the U.S., The problem of shearing distributor roll pins was virtually unheard of. In fact I'd never heard of it.

Guys you are doing something wrong.

Go with George's recommendations. Use stock Ford parts for oil pumps, pump shaft, and distributors.

I use a original Ford distributor made by Bosch Australia. It is 40 years old, has had it's points removed 30 years ago and replaced with electronics.

I have never seen a Ford distributor fail, but I have seen plenty of wiz bang aftermarket ones burn out, blow up, break mechanically or cause problems with something else.

Stick with Ford.

Tx folks...
George yes fully on same page
got new
STANDARD Oil pump
Standard Drive shaft
And got the install procedure on the gear from your sticky as well as the Ford spec (from Chuck)..

TX

Matthias

I have NEVER experienced a sheared roll pin on my car but I've always had aftermarket distributors, a Mallory dual-point then MSD RTR. I've owned my car for 35 years. I have, however, experienced this failure while driving at freeway speeds in my friend's '73. It had a Motorcraft big cap electronic distributor. I replaced the distributor with another Motorcraft distributor. More power to the person that takes the time to do a post-mortem to find the root cause.

The root cause of Ford distributor pin failure is and always has been dirty oil. Ford gearotor oil pumps are extremely intolerant of debris going thru the pump and breal drive pins & twist drive shaft extensions. Keep the oil very clean and things work as-stock. This does NOT include hi-pressure or hi-volume pumps! And some of the debris is deteriorated stock valve stem seals. GMs with their 2 gear oil pumps ignore debris until it gets ridiculous, and GMs use a distributor pin 3 sizes bigger than Fords and pump driveshaft extensions 4X larger.

Since few Ford owners seem willing to keep engines clean in our country, either upgrade the pin & shaft, or change your oil every 8K miles- or sooner if you drive a lot. This is regardless whether oil companies and Chev mechanics say you can get 30K miles before its necessary.

This is what it takes to snap the OEM oil pump shaft.

The cool part of this story is that the roll pin never sheared while this shaft was slowly twisting over years and miles of operation.

A burr inside a replacement oil pump is what caused this problem; this is why it is necessary to disassemble new oil pumps, deburr them, and clean them prior to installation.

i guess I've been around, I've seen several of the circumstances listed here that lead to a DGRP (distributor gear roll pin) failure. 1965 289 Mustang i was giv'n her what she got when the oil screen found a #8 lock washer from who knows where & let it pass through the relief hole under the metal strap of the std screen assy. Yes there's a hole in the screen under a metal strap if you can believe that, same style as the 351C-2V oil screen. so NO the lock washer did not navigate the pump when it came to the smash your oil flat section of the gearotor meshing and the OPDS (oilpumpdriveshaft)did it's best impersonation of a barber pole as shown above but it did not break before the engine shut down due to the roll pin fuse letting go

the roll pin acted as an oil pressure switch

another time was the same thing debris in the pump stopping the works but a single strand of a wire wheel? YUP a tiny little wire wheel strand stopped the oil pump & broke the DGRP. this time the OPDS did not twist at all and was undamaged probably due to low rpm at the time of the incident. this was a late model 70's smog 302 IIRC

then there was the time i had 20-50 in my own 351C, the weather was getting cooler and i had fouled spark plugs from chokeless operation of a dual quad tunnel ram. so during an attempted start & warm-up of said beast, the fouled plugs coughed one time too many / too hard & stopped the fun for that day ... broken DGRP. this engine broke the DGRP multiple times before i regained my senses & used proper grade oil. and YES it was an HV pump btw

note that all instances are outside of normal design parameters ie; trash in the oil and oil grade not correct for conditions

also note that due to the failure of the DGRP all incidents were easily repaired and the engines were back in service quickly, none required complete rebuild due to operating with no oil pressure as they may have if they kept running after the oil pump stopped turning. nor did any damage the drive gear on the camshaft as they may have if the DGRP remained intact causing a failure of the distributor gear itself

YMMV (your mileage may vary)

quote:

Originally posted by George P:
This is what it takes to snap the OEM oil pump shaft.

The cool part of this story is that the roll pin never sheared while this shaft was slowly twisting over years and miles of operation.

A burr inside a replacement oil pump is what caused this problem; this is why it is necessary to disassemble new oil pumps, deburr them, and clean them prior to installation.

i'll suggest that the burr found in the pump was evidence of debris that stopped the pump at rpm. possible the debris made for the shadows and was never found but that what happens when the engine is chooching when the oil pump stops

still always good advice to inspect deburr & clean new pumps before putting them into service, how many times have you read a thread about a new build only has pressure cold & fades quickly during warm-up?

the relief valve in the new pump is stuck open on trash

I had a 65 Mustang 289 twist the shaft as George posted. The cause was a piece of the original plastic coated timing chain gear got lodged in the oil pump. I saw the oil pressure drop and then started hearing the lifters and pulled over. I have a Crane roller cam in the Pantera and I read that I needed a Brass gear. I put it on the MSD (measured exactly) and drove for about 1500 miles and decided to check it for wear. It was already wearing. I said what the heck and got a Ford steel gear. With all the hoopla about the pin I put 2 in. One in the standard location then drilled another hole 90 degrees rotated and above the original pin location. No issues for years, maybe because I change the oil regularly.