Changing seal on harmonic ballencer 98 GU

[Mattonpatrol]

Hey all changing seal on harmonic ballencer on a 98 GU patrol, Just wondering if it's a hard job as I haven't done this before and what are some steps or special tools or precautions on doing this job, thanks guys!

[lhurley]

I havent done it on my gu, but i helped my housemate do his on his gq. Not going to lie mate, it wasnt very fun.

There are special tools needed, like a bigger socket and a harmonic balancer puller to list a few. You also need to be very careful removing the old seal as if you damage the crank shaft or the opening in the block, you can be in a world of hurt. Same goes for the new seal, it shouldnt damage the engine but it can easily damage the new seal, leaving you no better off then before you started.
This sort of job would come under the advanced category when it comes to working on cars. If you have a mate whos done it before or is a mechanic, by all means give it a crack or even if you feel like you can yourself, im just saying having done it, i could do it again but would most likely just pay a mechanic to do it.

There is a write up on how to change it for a efi 4.2 gq, on here somehwere. I dont see how it would differ much, my 4.5 looks very similar to my mates 4.2 petrol.

[Rustyboner81]

did my GQ rb30 crank seal.
there are a few things to think about.

how to remove crank bolt - youtube has plenty of clips, i backed mine up against a/c compressor bracket and cranked engine with coil disconnected (scottykilmar.com is a good one)

how to get the balancer off - easyish with right tool. (harminic ballancer puller)

mine was petrol but i assume you'll still have to get the cam gear off. (small gear puller makes life easier but can lever them off)

get seal out - can use screw driver but i bought a cheap seal puller

process would be pretty much the same.
take bits off one step at a time.
i pulled my radiator out and fully flushed radiator and coolent system at the same time

DO NOT MISPLACE THE KEYSTEEL THAT KEEPS THE CAM GEAR LOCATED ON THE SHAFT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

GET EVERYTHING LINED UP FIRST LIKE
TIMING MARK WITH CYLINDER1 AT TOP DEAD CENTER, it'll help you out if you need to remove timing chain.


completely clean everything so it goes back together easily.

ive only done the seal once but ive been in there a couple of times once for valve timing and once to change head gasket.
very doable and a $20 seal compared to $1000+ however if you do it yourself you wont have any warrenty but you will learn a sh!t load as that is the path you take to do many other things such as head gaskets, timing belts and chains, oil pumps etc.

i would encourage you to try if you are confident enough on the tools

good luck mate, make a thread for others to follow

Russ