[FantomPoncho]

Let me give all of you some background on my problem, then I'd like some suggestions. If you say I need to yank the motor, THEN I'll blow my brains out...Here goes...

Went out one morning to fire up my '78 T/A and nothing happened. The carb had been running crappy for a long time, so I figured it was time to get a new one. I get one ordered. While waiting for the carb, I figure it's a good time to fix the water leak around the timing cover.

I proceed to fix the leak.

Upon putting the balancer bolt back on, I notice something strange. It was not a 15/16 bolt (actually I noticed it when taking it off, but just shrugged it off). Went to torque to 160 ft/lbs and it slipped at around 100. Pulled the bolt out and the threads were galled on the bolt.

To make a long story short, the bolt was very odd size of 18mm fine thread. I figure some lazy mechanic in the '80s stripped the threads and this was the next tap size. It took me a week to find a replacement bolt. It worked and the balancer torqued to 160. Yeah!!! - Not so fast...there's more.

My carb comes, I bolt it on, and the car won't fire. After compression checks and some troubleshooting, the cam is bad. So I proceed to fix this problem. Get the replacement cam in, test compression on all cylinders and they are right on. Put the front of the motor back on, go to torque the only metric hunk 'o metal on this car and...doh! No dice. This time the bolt slips again.

I haven't verified this, but I'm pretty sure the threads in the crank are galled.

Anyone dealt with this before? Is there a way to fix the threads without yankin the motor?

Help!!!

[FantomPoncho]

Let me give all of you some background on my problem, then I'd like some suggestions. If you say I need to yank the motor, THEN I'll blow my brains out...Here goes...

Went out one morning to fire up my '78 T/A and nothing happened. The carb had been running crappy for a long time, so I figured it was time to get a new one. I get one ordered. While waiting for the carb, I figure it's a good time to fix the water leak around the timing cover.

I proceed to fix the leak.

Upon putting the balancer bolt back on, I notice something strange. It was not a 15/16 bolt (actually I noticed it when taking it off, but just shrugged it off). Went to torque to 160 ft/lbs and it slipped at around 100. Pulled the bolt out and the threads were galled on the bolt.

To make a long story short, the bolt was very odd size of 18mm fine thread. I figure some lazy mechanic in the '80s stripped the threads and this was the next tap size. It took me a week to find a replacement bolt. It worked and the balancer torqued to 160. Yeah!!! - Not so fast...there's more.

My carb comes, I bolt it on, and the car won't fire. After compression checks and some troubleshooting, the cam is bad. So I proceed to fix this problem. Get the replacement cam in, test compression on all cylinders and they are right on. Put the front of the motor back on, go to torque the only metric hunk 'o metal on this car and...doh! No dice. This time the bolt slips again.

I haven't verified this, but I'm pretty sure the threads in the crank are galled.

Anyone dealt with this before? Is there a way to fix the threads without yankin the motor?

Help!!!

[Z Code 400]

I have fixed a number of cranks with a Heli-Coil Thread Repair Insert. No need to pull the crank as long as you can get a drill in there. I have used a 90°drill with great success...Robert

[FantomPoncho]

I've thought about the thread repair idea. Is there a thread repair kit for an 18mm fine thread? I found that even specialty bolt places don't even stock that size bolt, let alone a thread repair kit.

[cioccoj]

If your going with a helicoil you don't need an 18mm. Use something american thats close. Your going to drill, tap and install a coil anyway.

[72firechicken]

I too have also repaired theards in cranks with the heli-coil kits and they have worked great also I have not had any problem getting odd size crank bolts from my local fastner supply.

[FantomPoncho]

72Firechicken, I'll be looking for a thread repair kit and give that a shot. For kicks and giggles, call around your local fastener shops and ask for a M18 x 1.5mm grade 8 bolt in any length. I'll bet you'll get plenty laughs and jeers. I ended up getting my bolts shipped from a place in Maryland. BTW, I live in AZ.

I even called ARP and they laughed. I started combing the import dealers, bus and semi-truck repair places. I found ONE place with ONE bolt, but it wasn't grade 8.

I hope finding a thread repair kit won't be nearly as hard.

[mc69ta]

Hello
If you use a heli-coil kit to repair the crank
get the stock crank bolt and the kit to match it

Good luck
Mike

[79firebird_99TA]

Whatever you do, don't blow yer brains out! That might mean that you'll never get that Pontiac repaired and back on the road!

[mechanickeith]

Paul, Give me a call this evening, I will see what I have available in helicoils & keenserts

[FantomPoncho]

Will do, Keith. I was just shopping helicoils. For the size I need, $150 bones not including the drill bit. Ouch!!!