i read a bunch about the replacment of these gaskets. my question is it possible to back the bolts out of the the case, clean the surface with some brake cleaner, and drop the gasket in from the top. i realize i would have to pull all of the accessories, but it sounds a lot easier to do that than pull the cam, and all of the gears. does anyone have a PDF manual on these engines? i dont know if there is enough room behind the timing gears to slide the case out far enough to get a gasket in there.

 

You'd be able to pull the case out about 1/4" or so roughly, but would be a major pain to clean up the backside enough to get it seal with a new gasket. Just pull the cam and put a new gasket in. And while you have the stock cam out, put a performance cam back in.

 

Dealers sometimes used that method when repairing case leaks under warranty.
It does work sometimes but I feel it's half azzed.
Pull the cam and do it right or follow the case replacement instructions below.

If you want to make it easier

Most Cummins shops no longer remove the cam when replacing the case, cuts about $600 off the bill. By not removing the cam you don't have to take the front end all apart, remove valve covers or fool around with wooden dowels.

After the timing case cover is off turn the engine till the line up marks on the gears are lined up. A high quality three prong puller (Snap On is best) is used to remove the gear off the cam but there is also a special Cummins puller made just for it that works way better. The gear goes back on by heating it and sliding it on to the cam.

The gear can be heated in two ways, 1) Toaster oven, next to the truck so the gear does not cool down: 2) Propane space heater, one that can have the elements turn up like a grill. Set the temp around 300 F. The oven is the easiest way, depending on the oven it could take 30-45 minutes to heat up, in the meantime you can clean some parts. The propane heater is faster about 10-15 minutes but you need to be fast because the gear will cool down faster and get stuck half way.

You need an extra hand for a few minutes to hold the cam from moving back and pushing out the rear cam plug. The cam is held by removing the fuel lift/transfer pump (don't drop the pump actuator arm into the crankcase!) and using a pry bar on the cam lobe, apply a little force to move the cam toward the front of the engine. The cam can move slightly but all you want is the cam not to move back when the gear is going back on. Once the gear is up to the temp, the crank and cam timing position has been set, someone is holding the cam from sliding back, you then grab the gear with high temp welding gloves and slide the gear back on, sometimes might have to tap it back with a plastic mallet or dead blow hammer but never with a steel hammer. I've done this three times and never had to use a hammer, the gear slid right on.

I would only recommend this to someone with mechanical experience. Sounds a little complicated but is way easier. There are three draw backs: 1) gear cooling down half way, then you have to wait 10 minutes to cool and remove it again to start all over; 2) Not aligning the crank and cam; 3) Allowing the cam to move back and pushing out the rear cam plug, then you will have to pull the engine.

Some people think this method causes a weaker fit for the gear but Cummins has been using this method exclusively for several years, I've never heard of a problem

 

Infidel,

Great info, sounds like it could really save some time. Good to know. Thanks.

 

Before you start this little project I suggest you check to see if the bolt that holds the rear of the IP in place is still there. Follow the flat bar that is bolted to the left side of the block. Near the top it bends outward and a bolt should be there. If it is missing I believe the weight of the IP warps the gear case cover enough to leak. Just for my education I'd appreciate it if you would post your findings.

 

QUOTE]Before you start this little project I suggest you check to see if the bolt that holds the rear of the IP in place is still there. Follow the flat bar that is bolted to the left side of the block. Near the top it bends outward and a bolt should be there. If it is missing I believe the weight of the IP warps the gear case cover enough to leak. Just for my education I'd appreciate it if you would post your findings.
[/QUOTE]
ill check it out tomorrow and try to let you know. thanks for the info. sounds like a winner.i really do NOT want to pull the camshaft. it sounds like a lot of work. how hot do you have to get the cam gear to get it back on there? and does it go back on very smooth? i would be very willing to give this method a shot. is there anything else to know about doing it that waY? thanks for the help

 

My instructions are complete and answer all your questions.
Read it again.

 

Considering all the other stuff you have to remove, the cam isn't much more. The time consuming process of replacing the lifters was the most difficult part. If you are reusing your cam that isn't necessary. We discovered the missing bolt early in the process, but I had taken the opportunity to get a PDR cam, so we went forward.......thus, it is only a theory that the missing bolt will cause a leak. The PDR cam gave me an honest 2 mpg increase and cooled my WOT egts by 100 degreees. It took approximately 58,000 miles to pay for itself.

 

If you pull the gear and leave the cam in place it's a lot less work.
In fact about 6 hours less at a Cummins shop.

 

That is in a shop, with the correct special tools, equipment, gloves and experienced mechanics. I have heard that Cummins no longer recommends the procedure, but I have no first hand knowledge of that. If the OP goes for it I wish him luck.

 

what is this PDR cam i keep hearing about. i am new to the 12 valve world. i have owned several 24s, but this is the first 12. i am getting almost 20 average MPG and if it really adds that much mileage i would be willing to do it. where can you find one and whats the price

 

http://www.pdrdiesel.com/catalog/Camshafts-30-1.html

Have you checked the bolt yet?

 

yes the bolt is still there. i just looked at it today. what cam did you go with. do you know what the specs are on it versus stock? Lift on the intake/exhause- and the duration? i am interested in this now. i didnt realize they were to inexpensive. i was expecting over a 1000 bucks for a performance cam. did you have to do anything to the valve train?

 

you da man infidel as always

 

I bought a new quick spool cam with new lifters. I wanted a regrind but they were out of stock. As for specs, I don't know but you can call them and ask. It performs as advertised is all I know. I already had 60 lb springs on the valves to accomodate my GSK and exhaust brake. If you don't have those I recommend them. PDR sells a GSK kit.