1G About to do complete timing belt replacement, replace front seals as well?

[XC92]

Self-explanatory. I'm about to replace the TB, BB & 3 accessory belts along with all the pulleys, tensioners and water pump. All OEM except the BB, which is Gates Racing, and WP, which is Aisin. OEM is pretty expensive and Aisin is not, but highly rated.

I'm using the upgraded OEM kevlar belt instead of the stock one. Probably unnecessary but it's just $20 more and you don't do this every day, and in case I ever try to boost the HP.

What I'm wondering is whether I should also replace all 5 main front engine seals, i.e. 2x cam & 1x crank, oil pump & BB, at least if they're not leaking or look bad, as relatively cheap insurance. I just replaced the rear seal when I took the trans out, although the stock one looked fine. I used Fel-Pro, not OEM.

If I do replace them, is it ok to go with National & Timken, or even Fel-Pro, since OEM is kind of pricey? Or is it OEM all the way? My car is stock, no mods, none foreseen any time soon (but as I said you never know).

And, anything else to replace while I'm at it? E.g. bearings, sprockets, spacers, harmonic balancer, bolts, etc.

Sorry if I've asked and been answered this before. I've done so much work on my Talon and asked so many questions, I've lost track.

 

[XC92]

Yes I use 5th gear and I do it with car on the ground so nothing can move

The car was on the ground but things did move. Was that because it was in 1st or because something's wrong or broken?

I need to do some stuff on the car on that side so I'll try it.

 

[pauleyman]

1st gear likely. I wouldn't concern yourself. Enjoy the car.

 

[waltah]

Second, that's what I do, hash out minute details. I'm a details person, always have been, always will be.

Speaking as another detail guy who has maintained and driven his own Mitsus since '96 and recently got a '95 GST, I think there's another side to the balance shaft question: The shafts were part of the design of the 4G63 from the beginning. The vibration they cancel isn't necessarily just a driveabilty issue -- it may also be a concern for the rest of the engine. Yes, the intake manifold/plenum/TB assembly is very stiffly braced, most everything else on the engine is pretty light, but removing any significant engine part that wasn't optional to start with when that changes how things work ... I'm more than reluctant. The people who built these engines were fanatics ... they designed and tested this engine as an assembly and though I accept that catastrophic balance shaft failures happen I wouldn't want to claim that the higher levels of high frequency vibration you get from taking out the shafts would be okay.

Probably it matters how you intend driving the car. As a sporty two passenger car -- that's in line with the design and testing. With mods to deliver a bunch more horsepower and racing or other high RPM/output driving the balance shafts might be a greater issue.

 

[XC92]

I'm the first type. No intention to mod, race, tune, launch, etc. If I ever had any desire to do these things it would have been years ago. More power to those who are into it, but it's not me. As such, I try to keep the mods to a minimum, only what makes sense for my situation and needs, like replacing stock bushings with poly, K&N air filter, SS hoses, better clutch, etc. But these aren't really a mods, more like upgrades. To me a mod is when you literally modify a stock part in a way not originally intended, as opposed to replacing it with an improved version. Perhaps the line is fuzzy but I'm trying to stay on this side of it. I'll leave true mods to the true enthusiasts.

Btw I thought that the precursor to the 1G DSM 4G63 didn't have balance shafts and that they were added later, perhaps for the turbo version. But were there provisions for adding them later, like openings on the engine front that were blocked off, or where they themselves mods to the original engine, and by deleting them folks are just reverting the engine to its original form, making this a de-mod more than a mod? In any case I'm keeping them in, since my car, driving style and maintenance routine don't appear to put me in the high risk group for serious balance shaft issues. In fact I just finished the TB job and am ready to test it out. A bit nervous, to be honest.

 

[steve]

While there is always a question of accuracy with wikipedia it's a easy starting place for information.

Balance shaft - Wikipedia

en.wikipedia.org

Mitsubishi Astron engine - Wikipedia

en.wikipedia.org

Mitsubishi Sirius engine - Wikipedia

en.wikipedia.org

 

[XC92]

Quick followup. I've driven the car several times since the TB job and everything seems good. No teeth skipping or weird engine noises or vibrations, engine responds the way it should, full power, that nice roaring sound from the engine when I accelerate, etc.

I haven't taken it on the highway yet or over 50mph. I like to test things in stages and I'm not quite there yet. It's getting cold enough that I don't want to have to wait for a tow truck in case the TB skips, as obviously I wouldn't be able to keep myself warm running the engine.

Only thing I'm noticing is this weird "growling" sound when I reengage the clutch after upshifting. But that sounds driveline and not engine-related. I'll look into it. But otherwise everything seems good. Still nervous that something will fail, but after all the work I've done that's probably normal.

Thanks again all. I couldn't have done it without you. I'll probably be mostly quiet here for a while. There's still some non-essential work to be done on the car but it can wait still spring and warmer weather. E.g. replacing rear bushings, BJs and links, getting body dents out, some painting, cleaning gas tank, etc. But I'll check in from time to time to see what's up.