Builds 1fz-fe rebuild (1 Viewer)

[satchel]

Hello all,

I've decided to tackle an engine rebuild for my wife's 96 LX450 over this winter, which means I'll be asking all kinds of dumb questions from the mud collective since I've never torn into the internals of an engine before. My typical MO would be to just start tearing everything down and figure it out later, but I'm going to try and be a bit more methodical with this project and seek advice where I'm not understanding the book.

So here we go, question 1:

In trying to remove my head, my LX FSM, page EM-19 states to put a service bolt (I'm assuming I need to buy one based on the description they provide, any links or other bolts on the engine that would work?) into a hole on the sub gear of the exhaust cam. The holes I currently see do not have any threads, so it may be that I need to rotate the cam to expose another one, but wanted to make sure.

Are there any items I need to be aware of otherwise? There is the big notification about keeping the camshaft level, but not sure how exact I need to be about that.

The "hint" says to make sure that the torsional spring force of the sub gear has been eliminated. How do I know that I've done that.

I'm assuming I need to rotate the cam to expose a hole with threads, and that I need to buy a screw and place it into the hole, but not sure if there is some torque value or anything else that would let me know I've taken the torsional force off of it.

Any insight is greatly appreciated, otherwise I'm going all in and hoping for the best!

Edit: stealing this list idea of parts to check/replace from @bryanb

1. Heater pipes running down firewall
2. Hoses
   1. Radiator top and bottom hoses
   2. Heater hoses by firewall
   3. Heater hoses under intake
   4. PHH
   5. Vacuum hoses, all
   6. Coolant hoses, all
   7. Power Steering hoses
3. Seals, Gaskets
   1. Rear main seal
   2. Oil Pan gasket
   3. Distributor Oring
   4. Transmission oil pump seal
   5. Transmission output seal
   6. Oil cover seal
   7. Exhaust manifold to Y Pipe gaskets and nuts
4. Water Pump
5. Power Steering Pump Replace
6. Starter Rebuild, contacts
7. Alternator Replace
8. Bronze bushing in block - machinist says they can remove and replace, but otherwise using landtank
   
9. ECU harness where it hits egr
10. Spark plugs
11. Spark plug wires
12. Cap/Rotor
13. Fusible link
14. Fuel Filter
15. Service Fuel injectors
16. Thermostat
17. Timing Chain Cover/gears/chain/slippers and all that mess
18. Clean
    1. Oil cooler on side of block
    2. Cooling system, reverse flush
    3. Radiator
19. Mods
    1. PCV catch can (maybe?)
    2. Switch to green coolant
20. Test/Check
    1. Vacuum Switching Valves

 

[sbman]

After you turn the cam the 35 degrees the manual states, you'll find the hole with threads. I used a small bolt that I pulled off some other part of the engine, you'll find one in your box/bags of bolts when you see the hole, it's not an odd size.

Keeping the cam level isn't as hard as it sounds, just back the bolts off the hold downs in even increments in a star pattern just like you would with head bolts. Keeps the pressure of the valve springs pushing up against the cam even so you don't warp/twist the camshaft.

 

[sbman]

Keep us posted on this one. When you put the injectors back in during assembly, be very careful not to pinch any of the o-rings or you'll have a leak. It's really easy to pinch one and not realize it. Use plenty of whatever lube you are comfortable with on the injector o-rings.

 

[satchel]

Perfect, that's exactly the kind of feedback I'm looking for, the things to watch out for. I'll keep updating this as I go.

Keep us posted on this one. When you put the injectors back in during assembly, be very careful not to pinch any of the o-rings or you'll have a leak. It's really easy to pinch one and not realize it. Use plenty of whatever lube you are comfortable with on the injector o-rings.

 

[inkpot]

Use a short bolt to draw the 2 halves of the cam gear together. It should be not much longer than the thickness of the gear so that it will clear everything when it is rotated around.

 

[satchel]

Thanks, that's good info. I read in another post that the bolts for the valve cover may work for the service bolt. I'll find out tonight and post back.

Use a short bolt to draw the 2 halves of the cam gear together. It should be not much longer than the thickness of the gear so that it will clear everything when it is rotated around.

 

[satchel]

I went to try and use the bolts removed from the valve cover and while they are the correct diameter, they are quite a bit longer than the fsm states, and would not allow the cam to rotate completely (not sure if that is needed yet). I started searching the rest of the block and the closest bolt to the fsm limits was on the bracket for the transmission lines, but it was still just barely short.

I then went to the truck and the first bolt I thought may work fit the bill. It is the bolt for the dome switch on the driver door. Since my wife is still driving the truck, I just switched the bolt in the transmission line mount on the spare motor with the dome bolt, and used the dome bolt for the service hole.

Notice the service hole once you have rotated the exhaust cam to expose it, it goes all the way through both gears, with the threads apparent in the main gear behind the sub gear. I wasn't understanding the spring detailed in the fsm until I found the hole. All you are trying to do here is put the bolt through both gears, so that the sub gear doesn't move clockwise or counter clock wise related to the main gear. Really cool seeing how that works and how it keeps the intake and exhaust cam drive gears tight against each other as they wear.

 

[satchel]

Next step in the fsm is to rotate the intake cam to where the 2 dots are at roughly 35*, and then push the exhaust cam back and start removing the bearing cap bolts. It states to push the cam back without excessive force.

I believe I have the dots where they are supposed to be, I'm assuming it is talking about these on the back. My question is, should the exhaust cam now easily move towards the rear. I've pushed it as much as I can with my hands but don't feel any movement in the cam at all. Any other tricks for getting this moved to the rear?

 

[satchel]

Still not sure about moving the exhaust cam rear and the intake cam forward, but followed the rest of the steps and I believe the cams came out level and secure.

The timing gear fell down about an inch, hoping that didn't somehow unseat the teeth on the crank, but otherwise I think it's coming along. Next up is removing the head.

Any advice on next steps or things to watch out for, please let me know.

 

[Rifleman]

Quote "Use a short bolt to draw the 2 halves of the cam gear together" end quote. When you've put everything back together DON'T forget to remover this bolt before you start the engine.

I know it sounds dumb, but I've seen small stuff like this get forgotten more than once. There has been more than one thread here on Mud about members forgetting to remover the socket holding their flywheel from turning when they tightened their harmonic balancer bolt.

They were shocked to hear a loud bang come from underneath their truck when they started it, all because they forgot to remove that socket.

What i did in my shop to make sure i didn't forget stuff like this. I made myself a punch list, I'd put items like this on it during engine tear down, then I'd check off those items during engine reassembly.

Plus I'd attach a copy to the steering wheel too, that way before i started the engine I'd check it again to make sure that everything on that list had been checked off before engine start up.

 

[ceylonfj40nut]

Hate to bring this up, but if your timing chain gear fell an inch it is hard to know if your timing chain is off. Hope you had a way to verify it is ok. When I did mine I took the timing chain cover off. I replaced slippers and chain. This will require you to unbolt oil pan 1 and 2. Easier to do on the engine stand. It was tougher with engine in the truck.

Use a numbered egg crate to hold your valve shims before you turn engine over if unbolting oil pans. This will avoid a major guessing game later.

 

[satchel]

I'm quite positive that I'm fine, but not going to place it in the truck without verifying. I'll have to research how to make sure the chain is on the right teeth.

 

[davidp14]

Along for the ride..

Thanks for sharing

 

[alia176]

Hate to bring this up, but if your timing chain gear fell an inch it is hard to know if your timing chain is off. Hope you had a way to verify it is ok. When I did mine I took the timing chain cover off. I replaced slippers and chain. This will require you to unbolt oil pan 1 and 2. Easier to do on the engine stand. It was tougher with engine in the truck.

Use a numbered egg crate to hold your valve shims before you turn engine over if unbolting oil pans. This will avoid a major guessing game later.

He is rebuilding the engine so the timing gear falling doesn't really matter a whole bunch. I'm assuming the front timing cover is coming off during this process and the timing chain slippers will get replaced?

 

[sbman]

I used a zip tie around the chain underneath the gear to take up the slack so that the gear could sit on the guides. they are metal coated with plastic. I don't know how many miles your engine has, but the timing chain is usually replaced during a rebuild.

 

[satchel]

This is correct, it's all getting replaced. I assumed it wouldn't be an issue since I need to tear into the chain at some point but without getting to that part yet I wasn't sure.

He is rebuilding the engine so the timing gear falling doesn't really matter a whole bunch. I'm assuming the front timing cover is coming off during this process and the timing chain slippers will get replaced?

 

[sbman]

This is how I set mine up for re-installation with the new chain and gears.

After I put the head on, I put pressure on the gear and sqeezed the chain with my fingers while I cut the zip tie so I maintained tension on the chain and held the teeth in place as I put the gear on the camshaft.

 

[satchel]

Thanks, that helps. I'm assuming the fsm will have pretty good instructions on where the teeth of the gears need to be when installing the new chain, but may ping you if I'm not getting it if that's cool.

This is how I set mine up for re-installation with the new chain and gears.

After I put the head on, I put pressure on the gear and sqeezed the chain with my fingers while I cut the zip tie so I maintained tension on the chain and held the teeth in place as I put the gear on the camshaft.

 

[sbman]

The FSM is really clear. There are colored links on the chain that you line up with marks on the gears. It's pretty straightforward. PM me or post here any time. I have hundreds of pics of the engine as I took it apart and put it back together.

 

[ceylonfj40nut]

No issues then if the front cover is being removed and inerds replaced. Thought you may not be doing this.