Head gasket replacement issues and crankshaft pulley bolt size?

General discussion about our beloved Tercel 4WD cars
Post Reply
User avatar
Mark
Highest Ranking Member
Posts: 782
Joined: Mon Apr 22, 2013 9:49 pm
My tercel:: 1984 Automatic, 1981 sedan
Location: Victoria, B.C.

Head gasket replacement issues and crankshaft pulley bolt size?

Post by Mark » Tue Dec 24, 2019 10:56 am

So the head gasket on my '81 Tercel started leaking coolant externally under the exhaust manifold so I ordered a gasket kit. I sprayed the new head gasket (composite style) on both sides with copper gasket spray. I was lucky that there was no warpage in the head or block (less than .002") so I didn't do any sanding, just spent about half a day with solvent and a greed scrub pad getting rid of all the old gasket residue. I re-used the old head bolts, which is what the Factory Service Manual seems to hint at. I ran a die and tap along all the bolts and holes and cleaned them up. When I was torquing them down on the first pass (only about 20 Nm), the first bolt sheared. I was lucky that it didn't shear completely (it was held together by a tiny piece of thread) so I was able to back it out of the hole. So I had to order a new head bolt set from Rockauto (they aren't available anywhere locally). They arrived a few days later and I replaced them all and torqued them down without issues. From now on, I will always use new bolts when replacing head gaskets. As I was putting everything back together, I decided to replace the crankshaft front seal since it was leaking oil. Off the top of my head, I couldn't remember if the threads on the pulley bolt were reverse or not so I guessed and just tried the normal way first assuming if it was wrong, it just wouldn't turn. It started to turn and came out, but the threads were all stripped off the bolt. So I had turned it the wrong way and the steel was soft enough to allow it to turn while stripping off all the threads. So now I'm stuck again since there are none of these bolts at any of the parts stores (including the Toyota dealerships) and the scrapyards on my island don't have any old Tercels. The dealership found one in California, but it will take a couple of weeks to get here. I don't suppose anyone knows what thread size it is? I'm guessing it's a metric M-something with left-hand threads? It's frustrating that something as simple as a bolt can stall a repair job for so long.

User avatar
rer233
Highest Ranking Member
Posts: 912
Joined: Sat Jan 01, 2011 1:49 pm
My tercel:: Multiple

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by rer233 » Tue Dec 24, 2019 3:08 pm

Mark- Bolt size is M12X1.25 and definitely NOT left-hand thread (just checked it on a spare I've got in my garage.) My guess is it was over-torqued during a previous repair. Hopefully the threads in the crankshaft aren't damaged...

Good luck!
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)

User avatar
Mark
Highest Ranking Member
Posts: 782
Joined: Mon Apr 22, 2013 9:49 pm
My tercel:: 1984 Automatic, 1981 sedan
Location: Victoria, B.C.

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Mark » Tue Dec 24, 2019 7:49 pm

That's good to know. So basically, I should be able to find that generic bolt from any hardware/auto parts store (with a washer) and not have to wait for the proper Toyota bolt.

User avatar
dlb
Highest Ranking Member
Posts: 6530
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: none currently, 7 previous
Location: shawnigan lake, bc, canada

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by dlb » Wed Dec 25, 2019 9:44 am

That's a bummer of a xmas eve, Mark. Sorry to hear it. I hope today is better!

User avatar
Mark
Highest Ranking Member
Posts: 782
Joined: Mon Apr 22, 2013 9:49 pm
My tercel:: 1984 Automatic, 1981 sedan
Location: Victoria, B.C.

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Mark » Thu Dec 26, 2019 7:21 pm

I've left it alone for a couple of days. I've come to realize that you can't get metric fine thread bolts locally either (even though we are supposedly a metric country). Just M12 1.75. I ordered a crankshaft pulley bolt for a early 2000's Corolla from the local Toyota dealership since they seem to be the same thread as the Tercel's and they can get it in within a week.

User avatar
Petros
Highest Ranking Member
Posts: 11230
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Petros » Fri Dec 27, 2019 8:05 pm

I am pretty sure all of the 4 cylinder Toyota engines use the same front pulley bolt, particularly from '80's and '90's. Perhaps even the larger engines but I would not know. I have rebuilt a number of different Toy engines, 3ac, 4ac, 4afe, 4age, and 20R. all had almost identical front pulley bolts. oddly there are both 17 mm hex, and 19 mm hex heads on them, even on the 3ac, may have changed after a certain date, but either is interchangeable.

you might find on off of any of those engines to work locally.

some one may have cross threaded the front bolt on yours, and left it. there is not that much stress on that bolt, it only holds the front pulley in place, that only has to drive a fan belt and the timing belt. many modern cars have gone to very large front bolts, with torque to yield type (meaning you have to buy a new one each time to take it off). takes massive amount of force to get them off, I can not figure out why. I will stick with the old engine designs, none of this torque to yield crap for me.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

User avatar
Mark
Highest Ranking Member
Posts: 782
Joined: Mon Apr 22, 2013 9:49 pm
My tercel:: 1984 Automatic, 1981 sedan
Location: Victoria, B.C.

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Mark » Fri Dec 27, 2019 9:56 pm

The last person that put that bolt on was me a couple of years ago when I replaced the timing belt. I don't remember having any issues with putting it in. I've done that job several times on different Tercels and never had a problem with that bolt. The Tercel bolt I ordered from Toyota that was supposed to take 2 weeks came in today(!). I tried carefully threading it in to the crankshaft and it would only go in slightly crooked. I only wrenched it in a thread or two, but the female threads seem to be cross-threaded. I'll try and track down a tap tomorrow to see if I can salvage them.

xirdneh
Highest Ranking Member
Posts: 2005
Joined: Thu Aug 04, 2005 11:38 am
My tercel:: 87 tercel 4x4 wagon w/reringed engine, 83 tercel 4x4 wagon w/salvaged engine and 4.1 Diff's
Location: seabeck, washington, USA

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by xirdneh » Sat Dec 28, 2019 6:32 pm

what about the torque wrench? is it accurate?
i have done a lot of these tercel heads and never broke or stripped a bolt
i did test 7 torque wrenches i had available to me and at least three were way off.
Love those Tercell 4x4 wagons but they sure suffer from road noise.

User avatar
Mark
Highest Ranking Member
Posts: 782
Joined: Mon Apr 22, 2013 9:49 pm
My tercel:: 1984 Automatic, 1981 sedan
Location: Victoria, B.C.

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Mark » Sat Dec 28, 2019 7:05 pm

The torque wrench I used was borrowed from work. They are calibrated yearly (this one had a current sticker). Today I found a M12-1.25 tap and cleaned up the threads in the crankshaft. It almost felt like I was cutting new threads the whole way. Everything then went back together fine. After starting it up, setting the timing and letting it idle until it was warm and then some, I shut it down and let it cool. The I re-torqued the head bolts. I was able to get 1/4 -1/2 a turn on them. After driving around for a while, everything seems fine with no leaks.

User avatar
Petros
Highest Ranking Member
Posts: 11230
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Head gasket replacement issues and crankshaft pulley bolt size?

Post by Petros » Mon Dec 30, 2019 7:38 pm

Mark wrote:
Sat Dec 28, 2019 7:05 pm
The torque wrench I used was borrowed from work... calibrated yearly.. Today I found a M12-1.25 tap and cleaned up the threads in the crankshaft. ... After starting it up, setting the timing and letting it idle until it was warm and then some, I shut it down and let it cool. The I re-torqued the head bolts. I was able to get 1/4 -1/2 a turn on them. ...
Good choice of the torque wrench. I too have verified calibration on typical auto parts store torque wrench and found very disappointingly large errors, up to 7 or 8 ft lbs. I found a certified aircraft grade one at a garage sale (the guy was a retired A and P mechanic), and it is now my go-to torque wrench for all important bolts. it is not hard to calibrate an auto parts store one, and just mark the correct point on the indicator, and use that as your final torque mark.

You might consider putting some loc-tite on the front pulley bolt to strengthen the hold on the remaining threads. what you did is the best you can do for now, should hold. if that gives up you can put in a coil, but that would require the next size up tap, so wait until you might actually need it.

you should also redo the torque of the head bolts at about 400 miles, I like to do it with the engine still warm from driving. Not always necessary, but I find that even with the supposed "no retorque" head gaskets, if you do not do it, there is a good chance at about 1000-2000 miles, the head gasket starts to leak. An easy precaution, about half the time I find that at least one or two head bolts will tighten a bit more with the same torque on it at 400 miles.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

Post Reply