Cam gear didn't need pressing on...

2007 5.9

2007 5.9

West Coast Dyno Modifier
Joined
Jan 14, 2008
Messages
1,927
Went to install stock cam gea on the new cam and it just took a couple hit from a brass hammer to get on....WTF??? I thought they needed to be pressed on???

Called cam mfg and they said it was rare for a CR cam gear to not have to be pressed on, but to use the supplied bolt and torque it to spec and move on.

Shoul I be worried???

Too late...
 
I wouldn't be worried as long as the gear wasn't loose on the cam and you used the bolt on retainer. You did lock-tight that right?
 
Huh? Is this a truncated nose cam? Like we sell?

Or was this a normal length nose cam like the stock one you removed?
 
Here is a comparison of both noses. The truncated and the stock OEM stlye.

Which did you get?
 

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I was able to remove the gear from my stock cam with a few blows from a dead blow hammer. No way in hell I was getting it back on to the new cam without heating the gear and chilling the cam though.
 
JerrodGlover said:
I wouldn't be worried as long as the gear wasn't loose on the cam and you used the bolt on retainer. You did lock-tight that right?
Click to expand...

Yes, torqued bolt to spec with red loctite.

Soup Nazi said:
Huh? Is this a truncated nose cam? Like we sell?

Or was this a normal length nose cam like the stock one you removed?
Click to expand...

Don, I don't know. I dropped truck off with cam and installer called and asked if he needed to use the bolt to hold the gear on because it went on with a few raps of a brass hammer, but it's not loose in any way but just not a pressed on fit.

Soup Nazi said:
Here is a comparison of both noses. The truncated and the stock OEM stlye.

Which did you get?
Click to expand...
 
2007 5.9 said:
Yes, torqued bolt to spec with red loctite.



Don, I don't know. I dropped truck off with cam and installer called and asked if he needed to use the bolt to hold the gear on because it went on with a few raps of a brass hammer, but it's not loose in any way but just not a pressed on fit.
Click to expand...


Few raps of a brass hammer. :bang We heated the gears, and they went on pretty easily.
 
where did you go to get the cam installed i am debating where or not to do it myself or have some else to it.
 
i always heat the gear up 450 degress and it goes right on.noway in hell its goin on with a few hits from a brass hammer.
 
Soup Nazi said:
Did the bolt, retainer and such look like these in the photos on this page?

http://www.f1diesel.com/helixspecs.html

Did the gear require machining or did the stock gear bolt to the new cam?

Help. LOL Im trying to determine whats cooking here.
Click to expand...

I dont know what's cooking Don....

The installer told me that there was a retainer and bolt included with the cam and he installed it and everything went good. Had to clearance the timing cover a wee bit to clear the bolt but that was the only hang up.

He stated that the gear was by no means loose, it was a very snug fit, just no pressed on fit. With the cam bolt torqued to spec the cam gear had ZERO play.

When he installed it the cam thrust was in the .004 range, so the retainer worked as to be expected.

All in all HE was satisfied with the install and as am I...he is a 20year Cummins Master Tech, so I trust his judgment.

I have a habit of jumping to conclusions without basis....so I was putting this thread up in fear of something being wrong, instead of waiting for the job to be done...:bang
 
How did they remove the gear? Did they heat it or press it off? If the heated it with a torch they could of heated it beyond the point of return (oversize). If they pressed it off and it slipped right on one would think they would of pulled it off and checked it with calipers (gear and cam nose).
 
Bponci said:
How did they remove the gear? Did they heat it or press it off? If the heated it with a torch they could of heated it beyond the point of return (oversize). If they pressed it off and it slipped right on one would think they would of pulled it off and checked it with calipers (gear and cam nose).
Click to expand...

A combo of torch and press got the gear off.
 
CT2500 said:
i always heat the gear up 450 degress and it goes right on.noway in hell its goin on with a few hits from a brass hammer.
Click to expand...

That's way too hot! No need to go above 250*. The steel stops growing after that. I use an induction heater almost everyday to install bearings. 250*max. Drop right on.
 
A couple things:

There are two gears used. One is steel and one is ductile iron. The marine gear for the 12V is steel. All the rest used are ductile iron.

Per the manufacturer for Cummins gears: 300 degrees max on the ductile iron gears and 350 on the steel marine gear. No exceptions. It will weaken the heck out of the gear. I have seen them break after the use of a torch to remove them. The surface heat is thousands of degrees with a torch.

A standard press will work for removing and installing. No heat is really needed, but it can be easier to do if the heat is kept within those parameters above.
 
I heated mine in my BBQ grill at 300* for 30 minutes while the cam was in the freezer overnight and I still had to use a 20 ton press to get it on... along with random tapping from the hammer to help. No way it should come off now, lol.
 
Through the gear in the oven and the cam in the freezer for 20 minutes and the gear fell on with a "clink".
 
Bponci said:
If i were you i would change the gear asap before it bites you.
Click to expand...

What can happen???

I was under the impression that the cam gear on a CR isint under high stress, so what could happen???
 
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