2007 Tahoe Timing Chain Replacement

[Rocket Man]

I think the point of assembly lube is that it's heavy with molybdenum and other super slippery ingredients in a medium that is thick and sticks better than oil. It's to ensure the new parts that haven't bedded in to their abutting parts don't drag/jam immediately following the first start. After a few seconds, it's all flushed away by engine oil. But, the lubricating properties are still all in that oil.

I run diesel oil for the strong zinc and moly content. I dump in a bottle of Lucas ZDDP additive every other oil change just to be extra and make the guys at Blackstone pop böners. Diesel oil and that ZDDP additive are not supposed to be ran in an engine that has cats cuz, supposedly, zinc will kill the cat(s).

I know the point of assembly lube, just never known anybody to use it for a timing chain. There’s no “ bedding in” like with bearings and such. It definitely has its place, there’s no doubt about that. I mean, it won’t hurt but imo it isn’t something commonly used for this. At least not in my experience.

 

[Plimbob]

@ IAMDUB, I have a set from Harbor Freight. I'll grind the tops of the claws flat so they can slip in behind the sprocket. Do you recall if you used the 3 inch or the four inch?

I wanted to check because I thought maybe there was a special puller for that sprocket.

 

[Plimbob]

Update #4 - ground the tops off the claws on the 3 jaw 4 inch Harbor Freight puller so they were relatively flat. This allowed a little better grip. However, that sprocket does not want to come off, I heated it let it cool several times and no go. I was leary of putting to much pressure on it in fear of breaking a tooth off and the I would be in a pickle.

At this point, I am entertaining the thought of quit screwing around on it and leave it on. I inspected the teeth and there is no visible damage. I know that after 306k there has to be wear and leaving it on is not a wonderful idea all things considered but I need to get this !@#$ done and get it out of the garage.

Any thoughts on leaving it on?

 

[Rocket Man]

Update #4 - ground the tops off the claws on the 3 jaw 4 inch Harbor Freight puller so they were relatively flat. This allowed a little better grip. However, that sprocket does not want to come off, I heated it let it cool several times and no go. I was leary of putting to much pressure on it in fear of breaking a tooth off and the I would be in a pickle.

At this point, I am entertaining the thought of quit screwing around on it and leave it on. I inspected the teeth and there is no visible damage. I know that after 306k there has to be wear and leaving it on is not a wonderful idea all things considered but I need to get this !@#$ done and get it out of the garage.

Any thoughts on leaving it on?

I’ll tell you my experience and I’m not saying what you should do. I had the exact same issue when doing mine. The only way I could see mine coming off was with a torch, cutting it off. I bent a puller on it, it wouldn’t move. I had 150k at the time, so about half the mileage as you. I compared the new one that came in my Cloyes timing set and couldn’t see any wear on the original compared to the new. I also needed to be done, it was my daily. I left the old one on. It’s still on but I’ve only put 25k on since then. Hard mileage though, with a blower. I don’t worry about it. I have to say though that 306k might give me pause, so idk.

 

[Dustin Jackson]

Update #4 - ground the tops off the claws on the 3 jaw 4 inch Harbor Freight puller so they were relatively flat. This allowed a little better grip. However, that sprocket does not want to come off, I heated it let it cool several times and no go. I was leary of putting to much pressure on it in fear of breaking a tooth off and the I would be in a pickle.

At this point, I am entertaining the thought of quit screwing around on it and leave it on. I inspected the teeth and there is no visible damage. I know that after 306k there has to be wear and leaving it on is not a wonderful idea all things considered but I need to get this !@#$ done and get it out of the garage.

Any thoughts on leaving it on?

@Plimbob I am in the middle of doing an AFM delete on mine and I left my timing gear on the crank, didn't look worn. I only used a new timing chain and a new cam sprocket.

 

[Geotrash]

Update #4 - ground the tops off the claws on the 3 jaw 4 inch Harbor Freight puller so they were relatively flat. This allowed a little better grip. However, that sprocket does not want to come off, I heated it let it cool several times and no go. I was leary of putting to much pressure on it in fear of breaking a tooth off and the I would be in a pickle.

At this point, I am entertaining the thought of quit screwing around on it and leave it on. I inspected the teeth and there is no visible damage. I know that after 306k there has to be wear and leaving it on is not a wonderful idea all things considered but I need to get this !@#$ done and get it out of the garage.

Any thoughts on leaving it on?

If it looks nearly indistinguishable from a new one laid next to it, then I say send it!

But if it's really bugging you, this thread shows how to do it with the proper Kent-Moore tool:

Removing Crank Gear...problems - LS1TECH - Camaro and Firebird Forum Discussion

Generation III Internal Engine - Removing Crank Gear...problems - Having a hard time getting the 3 jaw pulley to hook on the crank gear, it keeps slipping. Any pointers out there to get this off?

ls1tech.com

Remover:

Reluctor Gear Puller J-41371

Reluctor Gear Puller J-41371 7.4L ENGINE C/K The 1996 7.4L big block engine features crankshaft reluctor gear which has an interference fit to the crankshaft. J 41371 is used to properly remove the gear without damaging the reluctor teeth. J-41371 is used

www.freedomracing.com

Installer:

General Motors GM-41665-A Crankshaft Balancer and Sprocket Installer

This tool is used with the draw bolt and nut from tool GM-41478. If you want to buy just the bolt and nut, the part numbers are 280055 and 90592A034 . When used on LS7 engines, GM-47812 is required instead of 280055. Includes GM-41665-1 and GM-41665-2.

www.tillmantools.com

 

[Rocket Man]

If it looks nearly indistinguishable from a new one laid next to it, then I say send it!

But if it's really bugging you, this thread shows how to do it with the proper Kent-Moore tool:

Removing Crank Gear...problems - LS1TECH - Camaro and Firebird Forum Discussion

Generation III Internal Engine - Removing Crank Gear...problems - Having a hard time getting the 3 jaw pulley to hook on the crank gear, it keeps slipping. Any pointers out there to get this off?

ls1tech.com

Remover:

Reluctor Gear Puller J-41371

Reluctor Gear Puller J-41371 7.4L ENGINE C/K The 1996 7.4L big block engine features crankshaft reluctor gear which has an interference fit to the crankshaft. J 41371 is used to properly remove the gear without damaging the reluctor teeth. J-41371 is used

www.freedomracing.com

Installer:

General Motors GM-41665-A Crankshaft Balancer and Sprocket Installer

This tool is used with the draw bolt and nut from tool GM-41478. If you want to buy just the bolt and nut, the part numbers are 280055 and 90592A034 . When used on LS7 engines, GM-47812 is required instead of 280055. Includes GM-41665-1 and GM-41665-2.

www.tillmantools.com

I see that first one for about $35 on eBay used. Interesting, it slips behind the gear to pull from the back. And reading up, now I see why they’re so hard to remove- they’re heated up at the factory first and then installed. I knew it had to be something like that, they’re ridiculously hard to remove.

 

[Plimbob]

Update - I made one last ditch effort and went to our local farm implement store and bought a different 3 jaw puller which had flatter heads.

1. I ground the heads down further to get them even flatter on top.
2. I then used a short m16 x20 which would not reach the inside threads but turn on the crank stub. I greased the area where the bolt would sit in the crank stub.
3. The push rod for the puller had a point so I ground that flat as well so it wouldn't dance on the bolt head.
4. I attached the puller (grabbed much better) and put tension on it.
5. Heated the sprocket and added a little more tension and let it sit for 30-45 minutes, came back heated it again and put more pressure on it. Let it sit for another 30 minutes. The third time I heated it and put more pressure on it.
6. About the time I was going to lay off, I felt it give ever so slightly. So I continued the heat and pressure and it slowly came off. It took quite a bit of pressure to get it to budge.

I have had enough for a day, I'll install the new one tomorrow and get on with the rest of the reassembly. I assume you should use motor oil or assembly lube when putting the crank sprocket back on?

Thanks to you all for your continued help!
Tim

 

[Rocket Man]

Update - I made one last ditch effort and went to our local farm implement store and bought a different 3 jaw puller which had flatter heads.

1. I ground the heads down further to get them even flatter on top.
2. I then used a short m16 x20 which would not reach the inside threads but turn on the crank stub. I greased the area where the bolt would sit in the crank stub.
3. The push rod for the puller had a point so I ground that flat as well so it wouldn't dance on the bolt head.
4. I attached the puller (grabbed much better) and put tension on it.
5. Heated the sprocket and added a little more tension and let it sit for 30-45 minutes, came back heated it again and put more pressure on it. Let it sit for another 30 minutes. The third time I heated it and put more pressure on it.
6. About the time I was going to lay off, I felt it give ever so slightly. So I continued the heat and pressure and it slowly came off. It took quite a bit of pressure to get it to budge.

I have had enough for a day, I'll install the new one tomorrow and get on with the rest of the reassembly. I assume you should use motor oil or assembly lube when putting the crank sprocket back on?

Thanks to you all for your continued help!
Tim

I heard you can heat it up in an oven first, kinda like the factory did.

 

[iamdub]

I know the point of assembly lube, just never known anybody to use it for a timing chain. There’s no “ bedding in” like with bearings and such. It definitely has its place, there’s no doubt about that. I mean, it won’t hurt but imo it isn’t something commonly used for this. At least not in my experience.

Yeah, I wasn't thinking about the timing chain specifically. I was thinking the actual parts that rub together- cam and lifters, etc.

Although, I did pack mine with assembly lube just because.