vht

I have a 2004 5.3 out of a truck, it was the 24, gen III. Which Dura bond cam bearings do I need? The guy that does my machine work says there are 2 types, I hadn't really run into that so I thought I'd ask before I order.

G Atsma

You need the bearings for the 2003-2007 LM7. Looks like a mid year change during 2003
Cam bearing bore 1 & 5 (end bearings) is 2.346"
Cam bearing bore 2 & 4 is 2.326"
Cam bearing bore 3 (center bearing) is 2.307"

vht

I looked them up on Ebay, they have from 1997 to 2003 and 2003 to 2007. The later says 1 and 5 is listed as 2.347. Thanks for the info.

G Atsma

I got my info from Summit.
You got yours from Ebay.
Who do you think stands a better chance of being correct???

SAPPER

iTrader: (10)

Aren't they the same???

RB04Av

Most likely, 1 set of numbers is the bore in the block, and the other is the bearing OD.

G Atsma

I corrected my post above to reflect bore rather than bearing OD, to reflect how Summit states it

SAPPER

iTrader: (10)

I was poking at you G about ebay and Summit.
But as far as the cam bearing differences, yes there are early and late model versions. I can't remember if I made a Thread about this or just a reply in a post. but I explained, in detail, about each one.
Only need to check this on a Gen 3 block. Any gen 4 is all the same. I can't remember the bore dimensions right off, but one can google it. I've had many guys bring me their blocks with bearings to have me install them. Been a few with the wrong ones.

vht

I looked on ebay but also looked into Dura bond and Engine tech, they both said late 2003 to 2007, I bought this engine cheap and it only had 110,000 on it and was really hoping it was a Gen 4 but I wasn't that lucky. I also didn't know Dura bond were made in China until researching this.

vht

I tried to get a measurement on the front bearing, 2 different dial calipers, 2.300 is roughly what I came up with but its hard to get a even measurement. I ordered the CH10 and the Ch23's, that way I'll have the right set. I also ordered a dial bore gauge so I can accurately measure crap like this. I ordered a cam bearing tool so now I can just do this myself, the block has been setting at the machine shop for 6 mths with nothing being done, all I wanted was hot tanking and cam bearings, makes me mad because I've spent a lot of money there and they couldn't knock this one simple job out for me.

Che70velle

iTrader: (6)

You’ve waited 6 months for a wash and cam bearings at a shop? That’s a 3 hour job. They obviously have more work than they can get to. If they had an ounce of class they would have told you they didn’t have time for you.

vht

I know it wasn't a job they were going to make a lot of money on but the thing is I've had a ton of work done there, several BBC engines and 1 434 SBC. Plus I've had some machine work done on several customers I've had here at the garage. This is a budget moter I'm going to play with boost on, not going to get back into bracket racing just have some fun. When I get the tuning thing down, I'll build a forged motor, might have to rethink machine shops then.

CattleAc

iTrader: (7)

Why are you even messing with the cam bearings...???

vht

Because they are rough as crap and I've seen to many cams in a LS that had the bearings spinning around on them.

G Atsma

If an LS engine had bad cam bearings after ONLY 110,000 miles on it, you better look around for other issues.
LS engines usually go AT LEAST 2-300k miles before any issues present themselves.

Kawabuggy

iTrader: (1)

I'm with the OP.. I will replace cam bearings EVERY TIME in any LS engine I have opened up. Even when they have low-ish mileage, the cam bearings are almost always showing signs of wear. There is also a CH-25 bearing that is a little wider for even more support of the cam. When I have a block that uses that series of bearings, I always opt for the wider ones as I think this is one of those high wear areas in the LS engine. I also bought the cam bearing installation/removal tool so I do that stuff myself. Fortunately it saves me time sending the block out for cam bearings, and cleaning, when I can do it myself. We also have a chemical hot tank at my shop that I use for bare blocks.

vht

Mine ended up taking the CH-10 bearings, it must have been an early 04 block or who knows. I'm with you Kawabuggy, if you have one of these down, you are crazy not to replace them. I seen a guy on one of the drag and drive events that went by that "if you don't look at them, they are fine attitude" and lost oil pressure toward the end and guess what it was, cam bearings! Friend of mine pulled the cam on a 6.0 the other day and a bearing was completely out of the bore spinning on the cam.

Kawabuggy

iTrader: (1)

VHT, yes, I've disassembled MANY LS engines that have had a cam bearing completely out of the bore in the block. It's usually #2 that I find that moves-but I've read in posts here on this forum that many others have had different ones moving, or galled to the cam. The engine in my current shop truck had that issue (#2) on disassembly and I fought with it to get the cam out. So I ALWAYS replace cam bearings.. EVERY time.. After pressing out the old cam bearings, and before putting the new ones in-that's the time to get out the brushes and soap/degreaser and clean the heck out of the block. The reason Sloppy Mechanic says not to look at the cam bearings is because they almost always show some amount of wear. If the engine were still in the vehicle, and you were just cam swapping it I could see re-running them.. I would not like it.. but I would.. If the engine is out and apart-there is NO REASON not to replace them. The few extra minutes of time, and minor expense for bearings, is peace of mind for me. Just like replacing the cam retainer plate with the embossed seal is recommended at time of cam removal-for me replacing cam bushings is a "must do" step. I sleep better at night when I have new ones in the engine.

*If anyone in Houston needs to borrow the tool to remove/install cam bearings-I'll loan it out to anyone that wants to borrow it. No charge for rental, but deposit required if you want to take it with you. Unless you are building engines often it's just an unnecessary expense. So, it's here for anyone that needs it.