What parts to replace when doing timing belt service?

[chriscosta416]

Hi all, about to service my GX470 I had for a few years. Bought this for my mom so it will not see any wheeling.


I’m doing the TB/WP and here’s a list of things I have so far


TB/WP (pulleys, tensioner, etc)
Rad hoses
Radiator and cap (if it looks bad and old)
Cam, crank seals
Thermostat
Serpentine belts
Fan pulley bracket
Idlers
Spark plugs (not related)
Drive train fluids

Any other common items to replace I should know about?

US spec 2006 GX470

 

[GXfan111]

Wouldn't be a bad time to check for any old/ cracked/ leaky vacuum lines.

Also cleaning the MAF with some cleaner may improve some performance. Use a specific MAF cleaner and wait until its 100% dry before plugging it back into the truck harness.

Ive done these during timing belt jobs on my 4.7s, though not timing belt specific.

 

[Comet]

This is a pretty straight forward job. For the uninitiated, it will take a little longer than expected. I purchased new cam seals and crank seal. It’s stupid simple while you are in there.

 

[Jstawgn]

This is a pretty straight forward job. For the uninitiated, it will take a little longer than expected. I purchased new cam seals and crank seal. It’s stupid simple while you are in there.

On VVTI, it's a lot more tedious job. CAM have to be completely removed from the head. There is also a procedure to lock the split gear in place. Not difficult, but tedious job.

Recommended when you are nearing 200K anyway. I did mine at 180K.

 

[Rednexus]

Several folks on here have experienced valvetrain noise after VVTI cam seal replacement. It seems pretty easy to do more damage than good in replacing those seals. I'd personally skip seal replacement unless they are actually leaking; a bottle of AT-205 at the next oil change should keep them conditioned.

I would also check spark plug torque and potentially replace the alternator while you are in there (Denso remans should be under $200).

 

[71-CRUISER]

TKT-101 (inc water pump)
Thermostat
Serp. Belt
Serp belt idlers (2)
Upper and lower Rad hoses (opt)
Spark plugs
Oil
Coolant

Also I only replace the cam seals if they are leaking and after 20+ trucks I have never seen one leaking.

And you should be good for another 100k

 

[JAGI410]

Not a part to replace, but you might want to flush the heater core since you'll have all the coolant drained and it'll be an easy thing to tackle while you're there.