Top 2 bellhousing bolts thread into the eng case. Anyone know for a fact what the thread size is.

I measure 10.125mm using a thread gauge. Part store "customer enabling specialist" says there is no such thread pitch/size. All I need is a helicoil (sp) not sure what size to get.

10 x 1.25 would be correct

 

maybe he mis-understood you on thread size? anyone with a phone can look it up in 2 seconds, show him this:

 

http://www.amazon.com/Helicoil-5543-10-Metric-Thread-Repair/dp/B0002SRG34/ref=sr_1_1?s=automotive&ie=UTF8&qid=1455825864&sr=1-1&keywords=10+x+1.25+helicoil

 

timesert is another option and sometimes lower priced.

Edited February 18, 201610 yr by grossgary

If threads are messed up, you may be able to run a 3\8" tap in it and get enough thread back to use a 3\8" bolt. Hard to say but its a non critical fastener, I'd try that first

Do you need the bolts or are the threads stripped out of the block?

Twice I've had to run a 3/8" bolt all the way through and put a nut on the other end.

 

Threads in the block are either M10x1.25 or M10x1.5.

Thanks guys, got it handled. Went to napa bought a 10/1.25mm tap. Should have one anyway. Why is it that my tap n die set skips 10.125? I'm kind of new to subarus and japinese cars. Is that an uncommon size?

Among American market bolts/fasteners it is relatively uncommon. 

Among Asian and European vehicles, it is a fairly common size.

 

Tap kits often skip many sizes. M10x1.5 is a more common size found in tap kits because that tends to be used more often on newer American vehicles.