Caterpillar D4D fuel rack setting

[Shop Dweller]

Does anyone know the fuel rack settings for a D4D?
D330 engine, S/N 78A4087
I think that makes it a 65' model. The service manual clearly explains that to center is .312 from full throttle rack position. But, it is unclear to me if that is also the governed position. That is where it was originally set pretty much, but it seems like a really big coincidence to me that the rack setting is exactly the center of rack travel, although I know it's possible. Also is there a fuel injector housing service manual or a rack setting manual that covers these? I haven't found one. I have another manual on slightly older D330 engines that just says to refer to a chart that is in a different book.

 

[pittsburgh cat man]

Back then there was a book and fiche for rack setting info but what I see of the new sis I'm thinking you will have a hard time coming up with it. Might try technical at cat dealer

 

[Shop Dweller]

I have seen several of the rack setting books online but no one can seem to tell me if they cover my machine. Carolina Cat is no help with machines this old anymore. They can't even get you a part anymore if you don't come with a number.
I have a 64' model 6C with a D333 turbo. I could check it because I know it's set correctly, but not sure they would have the same setting, especially with it being turbo.
The reason I disassembled the governor was because the manual says you can't achieve full rack travel in either direction with a miss splined injector. Well I figured out the rack would only travel halfway. Upon dismantling I discovered the rack had a bur all the way around the access hole end. And the the thrust in the gov had a couple marks on the weight side. Apparently the throttle had been pulled so hard at some time that it grabbed the thrust by the weights and spun the rack. There was something there, some type of debris that cut a lipped groove all the way around the rack. Rack wouldn't pull out until I put an emory board down injector hole and rotated the rack against it.

But the book is wrong. I have put injectors in a tooth off intentionally to test that and I still get the full rack travel. Two teeth off will limit it, but not one. I even dropped just the plunger rod in the holes where I could see the gears. One tooth off on one with three timed correctly and I still get full travel. The new set of injectors have slightly different made gears with a slightly larger gap after the last tooth so maybe thats why.

Anyway I could put it back just like it was. Just seemed like 1/2 travel was a strange coincidence.

Back then there was a book and fiche for rack setting info but what I see of the new sis I'm thinking you will have a hard time coming up with it. Might try technical at cat dealer

 

[pittsburgh cat man]

I would really would not think the rack settings would be the same. It seems to me that engine should have a low oil pressure rack limiter but that was a long time ago i might be full of beans

 

[Shop Dweller]

I would really would not think the rack settings would be the same. It seems to me that engine should have a low oil pressure rack limiter but that was a long time ago i might be full of beans

It does not. I think that came along later. Talked to another member who said the D6B was governed on the center of the rack.

 

[Old Magnet]

I have the info you need but I won't have access until Monday afternoon. I'll post it then.

 

[Old Magnet]

Here's the info.....

 

[Shop Dweller]

Here's the info.....View attachment 354628View attachment 354629

Hey I really appreciate it Magnet. I finally conquered my overfueling issue. I spent too much time trying to accommodate aftermarket plungers. Or rather trying to make two different brands work together, when it dawned on me that the machining on them was probably all over the place. And it was. One type had helix rods in them so big the check valve wouldn't cover the hole so it could even work. I just put 4 old Cat ones back in and polished the checks up on a mirror with 1500 and soon as it hit after that I knew it was fixed. So now I can get the gov setup and put it back to work. Good thing too, they are predicting 20 inches of snow here this weekend and my driveway is a half mile and too steep for a tractor to handle that much snow.

Once again I appreciate it. Is there anyway I could get the form number on that book, if it was a book? I have a couple more machines from that era and I would like to have a rack book.

 

[Old Magnet]

There really isn't a Form number but you want to be on the look out for the 1966 or later edition.
Even then for some reason the 78A ratings were considered temporary and may not be included in some editions. I do have a spare Set of Rack Setting Charts that I was about to put on ebay. I will check and see if the 78A info is included and also check the year of issue.

Well I just checked and the spare I have is a 1960 edition.

 

[Shop Dweller]

There really isn't a Form number but you want to be on the look out for the 1966 or later edition.
Even then for some reason the 78A ratings were considered temporary and may not be included in some editions. I do have a spare Set of Rack Setting Charts that I was about to put on ebay. I will check and see if the 78A info is included and also check the year of issue.

Well I just checked and the spare I have is a 1960 edition.

Okay, I will keep an eye out for that. Have a couple 74A D6C machines too that would probably be included in the same book.