Hi everybody!

Recently acquired a Dodge D350 1991 with the Cummins 12V 5.9L engine.

Front seal was leaking oil very lightly...previous owner included seal with the truck...

Pulled the front timing cover off and noticed what appears to be a hole in the cover the size of a bullet near the top of the cover.

After browsing these forums I am convinced I've witnessed a miracle. The front cover has a hole in it, the pin is nowhere to be found. Amazingly the gears, and all other internals are damage free. The case is damage free. Good oil pressure, engine otherwise appears to run great!

So my question is, what is the deal with this dowel pin? Is it really necessary to replace it? Can I leave it out and put a new cover on? Suggestions? Do I need to replace the dowel pin? Or is the dowel pin only there for assembly purposes?

 

mines out and i didnt replace it and i have had no problems. Some will tell you to replace it but i have not had any problems

 

Just an other opportunity for timing to slip , if housing moves , it can also damage the gasket behind it [ leak ] .

 

Another question...

What does the KDP do exactly? What is its purpose? The pin keeps the housing from moving?

I see many "fixes" or otherwise that block it, grind it off, drill it out etc.

Don't those fixes also stop the pin from doing its intended job? Which is what exactly?

Thanks!

 

I agree its better to replace it, it indexes the case. I could see if it moved the oil seal would suffer not be square and prob. leak, but to John i thought the timing couldnt slip on you guys trucks due to the pump beeing keyed? Correct or no? I know it can on the 94-98 12v, thiers a key on there to but it's not used- it is a tapered fit. But i believe the older 12v acually use the key, this is why you can move the pump to adj. the timing. Someone correct me if im wrong i too would like to be more clear on this.

 

The pin hold the timing case in place for a few reasons , for assembly , to keep from moving , and because the fuel pump is mounted to the case , in order to get exact timing , the case has to have an exact mount [ the pin ] .
There are about 3 fixes , the newest is that the manufacture finely responded to an ongoing problem , this happened in the last couple yrs .
for older engines , there are 2 methods , TAB & JIG , the tab requires removing the cover & using a longer bolt to hold a washer over the pin , the jig is mounted to the outside of the case , to align the drill bit , then a tap for a bolt , to hold the pin in place .

 

The pump is mounted to the case that is aligned by the pin .
The timing is adjusted by pulling & remounting the gear on the tapered shaft , no key , so that is an other slipping opportunity .

 

Only p-pumps are taper fit. VE's use a keyway.

 

Thanks G1625S, thats what i was getting at, or trying to say. I just adj. the timing last night on my 97, was asked a few weeks ago by a guy to adj the timing on a 91 he said he thought it sliped. I explained to him what i said above, im glad i was right. Thanks

 

What threw me was in Johns sig it says 93 so i was thinking the old ve pump but then right after it it says 94?? Not sure what he has there.....

 

gotta ask the kdp king wannadiesel (dave) that man is amazing at the kdp ...was at a meet had to run to the parts store for a pulley came back and he was done killing the kdp....amazing

 

The 93 was the build date , but its a 94 model .
I was thinking 12v , hadn't noticed that it was a 1st gen till later .
I haven't been into the VE pump on the Cummins , but I have done a lot of the VW , basically the VW looked the same as the Cummins , the VWs are a tapered shaft .
If they made everything the same , then we could just swap parts , instead of buying new ones .