2000 z28..i just pulled the pan off and put it a new filter and gasket. and come to find out i have 3 stripped threads. i heard of helicoil what size would i have to drill out? i need a little help here.. thank you

 

Re-tap them with a M9 x 1.25 tap and put m9 x 1.25 bolts in.

No need for a helicoil

 

DON'T drill & tap to the wrong size. Big mistake all the way around.

The bolts are 8mm, "standard" thread, whatever that is. 1.25mm I think but don't quote me on that. ("fine" might be 1.0 or .75mm; you don't want those) Very common size. Very eeeeeeezzzy to repair CORRECTLY instead of the non-specific alternate-ethnic HACK JOB. Kit looks something like this plus you'll need a drill bit, which the kit will tell you what size it is. Check your local parts and hardware stores: they may have kits with the bit already there, might cost less, etc.

 

so i need the

M8 x 1.25 repair kit?

 

Heli coils suck. use a thread insert (thread-sert)

 

what size do i use.. is it a kit?

 

Yes, that would be the size. Yes, they are available as a kit, like the one I linked to. (which is not that I'm saying "buy this"; only, the thing you DO need to buy, looks something like this)

Not sure how "Heli-Coils suck". Sure, like just about everything else in the world, there might be something else better; but as far as being safe, effective, cheeeeeep, eeeeeeezzzzy, fast, readily available, EFFECTIVE, fool-proof, minimum of special tool requirements, ... all those things that us shadetree mechanic types NEED in our supplies, they're hard to beat.

Arguably the worst thread repair in many circumstances is the Time-Sert; but that particular one gets LOTS of hype on the car forums because it's what some of the car mfrs like to specify for NEW-CAR WARRANTY repairs. Guys that work at DEALERSHIPS get pounded over the head with those all the time. In that design, the threads are "synchronized" between the bolt and the outside, allowing the insert to be relatively thin; meaning for example, is you're repairing an aluminum LS or N* block with those silly 11mm head bolts, the new insert uses the same tiny threads that failed (pulled out of the casting, precisely because they were so tiny) in the first place. A 1.5mm pitch thread or whatever it is, isn't going to survive long-term in soft aluminum any better in a 12mm hole or whatever, than it did in a 11mm one. It's only good for getting a NEW-CAR WARRANTY claim back out the door.

However all that may be, use Heli-Coils for your pan screws. They'll work fine for what you're doing, you can get them down at your local street corner, and they won't break the bank.

 

yea it sounds like my best option. i just got to make sure i get the right kit. most likley its the

Helicoil 5546-8 M8 x 1.25 Metric Coarse Thread Repair Kit.. thats the original transmission pan bolt sizes

 

Ok, I won’t argue about what method is better. But I would like to point out some facts.
I work for a major car manufacturer. I asked 3 of my top technicians, one of which has over 30 years experience, in an unbiased manner, which would they prefer for thread repair. Heli coil or timesert. The exact way I asked was “given the choice for repairing threads, in general, what would you prefer.....helicoil or timesert”? ALL three of them responded immediately with no hesitation, timesert. One of them even said helicoil is junk in comparison. Another said helicoil will work in some situations, but he’s had them pull out and he would never use it on a head bolt hole. The reason auto manufacturers demand the use of timesert is because it’s a superior permanent fix. Not because it’s faster to roll out a new car warranty job. Helicoil is a good shade tree fix if you do not know how to correctly install a timesert. The room for error is a lot less. So helicoil would be a better choice for an inexperienced person.

if I were fixing something permanently, I always use a timesert or an ez loxk insert OR I chuck a grade 8 bolt in my lathe, a couple sizes bigger that the hole needing repair and I drill and tap it and make my own insert. Then it’s red loctite in place.

 

Ok now make that 4 for 4 technicians I asked so far, timesert much preferred. I’ll keep asking until someone says helicoil. It’s now a game for me. Thanks. Lol.

 

See what I was talking about? I sprayed the woodwork with the right chemical, it seems. They scurried out.

Heli-Coil is fine for what you need. Go down to the corner to AZ or Advance or Poop Boys or whoever, or to HD or Lowe's or whoever of those, and GET WHAT YOU CAN ACTUALLY GET out here in the real (non-stealership) world. It'll work completely fine for what you are needing.

Re. head bolts, the best solution I ran across for those, was some random d00d that made an insert that was ½"-13 on the outside (the threads are like 1/8" deep... PLENTY deep enough to penetrate into UNCORRODED aluminum in an old ratty corroded porous N* block) and of course 11mm x whatever on the inside to accommodate stock N* head bolts. Could even be used after a crappy DEALER-INSTALLED Time-Sert pulled out like the original bolt did, for the same reasons the original bolt did. Namely, inadequate thread depth, and compromised casting metal.

But none of that is particularly relevant here, except to expose the Time-Sert nuthuggers. Ignore them.

OP, use a Heli-Coil. It's all you need for what you're doing. Don't overthink it, don't outsmart yourself, just fix your car and get back rolling.

 

you proved literally nothing. If it was a better solution, Honda would use heli coils. They are much cheaper. And for a reason. I’d venture out and say that Honda’s requirements for reliability far surpass your acceptable level of reliability. The stealership? What do they steal? Funny thing is you’d recommend some substandard crap from an auto parts store vs factory level stuff which we all know always outlasts parts store grade parts. I wouldn’t use a heli coil on a lawnmower if you gave me a kit. But hey, some people are ok with half assing stuff.

 

For repairing a trans pan thread, helicoil is more than sufficient. It will be stronger than the remaining alum threads in the other holes. For a head bolt hole, timesert is preferred.

 

I'll say helicoil

 

For pan bolts helicoil

 

I'll say helicoil again.
A properly installed helicoil will be stronger than the factory thread in an aluminum block...even for head bolts

it is more cost effective, easier to install, and in multiple tests is equally strong or stronger than a time sert

just my .02

if a helicoil won't hold it...I doubt a time sert will either

 

I helicoiled all the bellhousing bolt holes in my LS1 block before putting it in my car. Steel threads are much stronger than aluminum....

 

I'll say properly installed Helicoil for the win.