923a2 Oil Leak from Behind Timing Cover

[roofconsult]

I have an oil leak that looks like it is coming from the rear of the timing cover where it bolts to the block. I checked the bolts on the front of the cover and a couple were a little loose, but can't get to the other bolts without taking the front cover off. Has anyone replaced the gasket between the cover and the block? It looks like the gears will have to come off and I understand the cam gear is difficult to reinstall.......not to mention re-timing.
Any advice would be most appreciated.

 

[Bandit02]

Not to bad of a job, the gears that need to be timed have timing marks you line up and a good gear puller can save you headache from having to pull the cam. I have never done one in a truck, rather on a stand but the last one I did the cover itself used RTV gasket and the new front crank seal had a installer tool with it from Cummins.

 

[roofconsult]

Not to bad of a job, the gears that need to be timed have timing marks you line up and a good gear puller can save you headache from having to pull the cam. I have never done one in a truck, rather on a stand but the last one I did the cover itself used RTV gasket and the new front crank seal had a installer tool with it from Cummins.

Thanks a bunch for the reply. No matter how much you study something it is always good to actually hear from someone that has done it before. So I have a couple of questions if you don't mind.
1. I would assume that the injector pump gear also has a timing mark on it? And can I leave the pump attached to the cover so as not to disturb the timing?
2. I've heard that the cam gear makes a very tight press fit to the cam. Any problems with putting it back on?
Thanks again.

 

[Bandit02]

You can leave the pump on with the gear (air compressor too), just makes it heavier and more awkward. I believe those pump gears are tapered and not keyed so their timing can be adjusted. The 8.3 I did was a ISC and those pumps don't require timing as it's a common rail design.

I hear that cam gear is super tight on the camshaft as well, requires heating. I think Cummins has a specific puller for that application.

For me I pulled the cam. It's easy because I could rotate the engine upside down and not worry about the tappets falling out lol. I know you can do that wooden dowel method of keeping them in but you'll need to pull the pushrods out etc.

 

[WillWagner]

Easier to pull the cam. There is a puller, but it requires pulling the cam out 4 inches to get the puller behind it, kinda a waste of time, and you need to heat the gear and be quick reinstalling, it will stick easily. The pump gear is not timed, but the pump is.Make sure you TDC the engine and lock the pump before you pull the gear. Follow the torque procedures when re assembling, the pump gear will turn if you don't. Don't leave the pump and compressor on the cover, you CAN leave the pump and compressor on the engine and remove the gear housing providing all of the supports are there for the two components. You'll want to drop the pan too because the front of the pan is mated to the gear housing. Don't use RTV. Oil attacks regular silicone. use a silicone based adhesive. I used a Threebond product, TB1215, it dries like the consistency of silly putty and is oil and heat resistant, I know others like permatex make an equivalent available at NAPA and other auto parts stores. AND, if you have a front cover that is flat, while you have it off, replace it with the newer style "sunrise" type. The old covers leaked all over the place and cracked at bolt holes. The new cover eliminates the leak/crack issue and eliminates the gasket, you only use the adhesive. The pic is of a cover from an ISC, but the mechanical engine cover will look like this except for the front seal area. The ribs emanating from the seal area is why it was referenced as a "sunrise" cover.

 

[roofconsult]

Thanks for all of the great information.
I figured I would just try retorquing the cover bolts and see what happens. Some of the bolts were a little loose. The leak slowed dramatically. After studying the photos and diagrams, it looks like of you take the cover off you can get to most of the gear housing bolts through the holes in the gears if you rotate the crank just right. So I have ordered a new cover gasket and crank/damper seal and will try applying a little torque to the housing bolts that are beneath the cover and gears.
Will let you know how it goes.
Thanks again for all of the help.