Looking for tips on replacing timing chain and gears

[E.D.75GMC]

I picked up a new timing chain + gear set for my truck from Summit, and I'm going to be installing it this week. Picking up the harmonic balancer puller tomorrow. Now, I've removed the timing chain cover before so I know how all that goes together, but I've never changed a timing chain or gears before. Now is there any particular way I have to go about this? Is there a special lubricant I will need? I placed the gears down on table in the way it looks like they should be facing. Thanks in advance.

[E.D.75GMC]

I should mention that it's a '75 350 4 bolt

[tinydb84]

I have done a few many years ago but dont remember it ever being difficult.

Line up the dots before you pull the chain and gears and dont move anything after. Other than that its pretty simple remove and replace. No special lube. Locktite the bolts if yours didnt come with the special locking washers.

[TrailerTrash]

make sure the puller isnt a 2 bolt setup. that wont work because it needs to be a 3 bolt triangle puller. if you know what i mean.

you are going to need a balancer installer aswell. unless you rent one of those tool kits that are the 2 in 1 set. i personally have a puller and installer that are separate tools.

are you going to drop he oil pan? if you have a one piece oil pan gasket you probably will have to drop it.

[E.D.75GMC]

Yeah I rented the balancer remover/installer kit from Parys Source last year when I did put in the Felpro one piece oil pan gasket, I'll make sure it's the same kit I get this time around. When you say "line up the dots" do you mean the bolt holes in the upper gear?

[gmachinz]

There are (2) "dimples" near the gear teeth-they line up 6 and 12. You are most likely going to need a smaller 3-jaw gear puller to remove the crank gear. If its a stock type link chain you're pulling and there is a lot of nylon teeth coating missing, I'd suggest dropping the pan to inspect and you'll most likely find a lot of it jambed up in the stock pickup screen. So if you have the pull the pan, its a good time to install a new oil pump too.

[jocko]

Your dots are not aligned. See the pic - the unfilled red circle is your cam gear dot. Your crank gear dot is not visible, and the chamfer is facing outward - turn it over and see if a matching similar dot is present on the crank gear (if so, turn the crank gear over so the dot is visible from the front of the engine).

Before you remove your OLD chain, rotate the crank and cam (by turning the crank by hand with a crank socket and ratchet and the chain still installed - if the engine was running fine before, the dots will align with every other rotation of the crank gear) until the dots on the old timing gears align (like the yellow filled in dots in the pic). Then unbolt and remove the cam gear and chain, then pull the crank gear. Press on the new crank gear with the dot at the TOP of the gear as shown in the pic (and aligned with the crankshaft key/slot - good time to install a new key if the old one is galled, etc). Then install the cam gear with its dot aligned with the crank gear as shown in the pic. Make sure to drape the chain over the cam gear in an approximate location before you try to align it to the dowel in the cam (AND over the crank gear first, then move the cam gear up to the cam bolt holes to take out the slack in the chain and align the dowel and bolt it in). If it doesn't bolt in with the dots aligned, remove and adjust the chain on the cam gear and try again. All the while, be very careful to not rotate the cam and crank gears. You don't HAVE to align them prior to removal, but it makes it a little simpler and keeps you from getting things phased 180 degrees out by accident. Remember that the crank rotates 360 degrees twice for each rotation of the cam gear.
Good luck!

[geezer#99]

Before you remove the old timing chain/gears, rotate the crank until the dots are at 6 on the cam gear and 12 on the crank gear. Unbolt the cam sprocket and wiggle it and the chain off. TAke a cold chisel and wack the crank gear right above where the keyway is between two teeth. The gear will split and then you can easily remove it.
To put the new chain on, just slide the crank gear on a bit, line up the dots and slide the cam gear into place. Use a block of wood to tap the crank gear into place.
In your pic you have the crank gear backwards. THe champfer goes to the inside. Torque the cam gear down and you're done.

[E.D.75GMC]

Okay I flipped the crank gear and lined up the dots, I'll post more pics once I get the harmonic balancer pulled and the timing cover off. Thanks a lot guys!

[Chevy_mud_truck]

Here a pic of them installed

[cadillac_al]

That's not a fun job. Nobody mentioned the fun of putting that timing cover back on. That is a pain, and why I hate doing this job in the vehicle. In a 4x4 you do have the ability to lower the oil pan. I would remove it and put a new gasket there too. I once had a timing chain so loose it wore a hole through the timing cover. Still ran good though.

[E.D.75GMC]

Yeah I pulled the pan and timing cover last summer to paint them and it was a pain in the a** putting them back on.
Now, how do I rotate the crank to line up the dots before I pull the old gears and chain off? And what's the best way to remove the crank gear?

[gmachinz]

I use a crankshaft socket to move mine.

[franken]

If the pan won't drop you may need to rotate the engine. I'd loosen the pan bolts so the timing cover can come off, get things lined up, replace the gears and chain, then rotate the engine, drop the pan and so on.
I did this on a Camaro last year and had to raise the engine, while not breaking the dist, after rotating the crank...

[E.D.75GMC]

While I was working today my dad went around to a couple automotive stores to get the Crankshaft socket. No dice unfortunately. Would I be able to insert the bolt back into here and use it to turn the engine over without damaging the crank? Although I would be afraid of twisting the head right off the bolt.

[Chevy_mud_truck]

Pull the spark plugs out and use the balancer to turn it by hand

[gmachinz]

Perhaps its the angle of the pic...but, do you have a woodruff key in the end of your crank snout? It almost appears as though its been sheered off.....?

[cadillac_al]

Last year when I was finally ready to buy a crankshaft socket, I got a lot of blank stares at the part stores and NOBODY knew what I was talking about or where to get one. Oh well, I have used that crank bolt before but I never recommend it. On a recently run engine with the plugs out, it should turn easy enough not to damage the bolt or threads. I guess the only place to get a crank socket is Summit or Jegs.

[MikeB]

Originally Posted by E.D.75GMC

While I was working today my dad went around to a couple automotive stores to get the Crankshaft socket. No dice unfortunately. Would I be able to insert the bolt back into here and use it to turn the engine over without damaging the crank? Although I would be afraid of twisting the head right off the bolt.

With the plugs out, you won't hurt anything by turning over the crank with the damper bolt.

Did you did loosen the first 3-4 pan bolts on each side? Clean that one-piece gasket as best you can and put a little RTV sealant on each corner where the gasket snugs up against the block.

Also, with the sprocket dots lined up, make sure your damper TDC mark lines up with the "zero" on your timing tab. If not, do some tweaking.

[gmachinz]

Originally Posted by MikeB

With the plugs out, you won't hurt anything by turning over the crank with the damper bolt.

Did you did loosen the first 3-4 pan bolts on each side? Clean that one-piece gasket as best you can and put a little RTV sealant on each corner where the gasket snugs up against the block.

Also, with the sprocket dots lined up, make sure your damper TDC mark lines up with the "zero" on your timing tab. If not, do some tweaking.

Agreed. With a worn stock chain prior to removal, you won't get them both to line up perfect-make sure you get the cam sprocket turned to 6 o'clock tho....the crank is easier to turn to 12 o'clock because you won't be fighting the valve spring pressure. Clean the 3 cam retaining bolts and threads with brakleen to dry them out-then use blue thread locker and torque them down. I also like to have the extra insurance of installing a cam lock plate too....CompCams among others make them. Its another one of those little "well, while I'm here I might as well...." things. Lol

[E.D.75GMC]

Read everything above and will be sure to follow all yoir advice! Now we've removed the old sprockets and chain, and just tapped the new crankshaft sprocket on. We tapped it until it stopped but is it still too far out from the block?

[gmachinz]

No, you're good-there is a small taper and once you bottom out you'll hear a "thud" to let you known you're all the way on. Now run the new chain around the crank gear, hold it up while you position the cam procket inside the top of the chain and line up the bolt holes being sure that once its seated, your dots are still 12 and 6. If not, move the crank a tiny bit until the cam sprocket bolts !cleanly! line up with the threads....then get each one started but don't tighten any until they all are in halfway at least....then gradually tighten them all up. Done. Then comes the fun part of sealing your cover and pan. Oh and you did get a timing cover gasket set with a new front seal, yes?

[RastaRobb]

Originally Posted by cadillac_al

That's not a fun job. Nobody mentioned the fun of putting that timing cover back on. That is a pain, and why I hate doing this job in the vehicle.

Yeah--no doubt! The pan is the worst.

[E.D.75GMC]

The two sprockets are supposed to be in line with each other I would imagine?

[geezer#99]

THey should if you have the chamfer on the inside on the crank gear and it's all the way on.
Take a pic of the front of the crank gear for us.