TR2/3/3A Gearbox bellhousing to motor bolt size?

[karls59tr]

It seems I've lost these bolts to the bottomless pit of my disorganized garage. Does anyone know the correct size of these bolts or where I could look it up?:concern:

 

[TR3driver]

If you look at the SPC https://drive.google.com/file/d/0B2...YmE2LWFiN2UtZWYzMjNjNGFiYzY4/view?usp=sharing, the bolts are listed as HU.0858. Then look that number up in the standard hardware catalogue https://drive.google.com/file/d/0B2...ZTk0LTk1YTUtZTIyZmU3ZTc1Y2M4/view?usp=sharing to find that they are 5/16 NC, 1" long.

 

[sp53]

nice

 

[karls59tr]

If you look at the SPC https://drive.google.com/file/d/0B2...YmE2LWFiN2UtZWYzMjNjNGFiYzY4/view?usp=sharing, the bolts are listed as HU.0858. Then look that number up in the standard hardware catalogue https://drive.google.com/file/d/0B2...ZTk0LTk1YTUtZTIyZmU3ZTc1Y2M4/view?usp=sharing to find that they are 5/16 NC, 1" long.

Something dosn't seem right. The bolts that hold the gearbox to the motor should be longer than 1" should they not?

 

[Geo Hahn]

...should be longer than 1" should they not?

Sounds right to me -- they're just going through the two flanges (and not all the way through at that).

 

[CJD]

And don't forget there are studs too...

 

[TR3driver]

And don't forget there are studs too...

And a couple of locating dowels as well.

 

[karls59tr]

And a couple of locating dowels as well.

OK. Thanks for the info.

 

[karls59tr]

Just occurred to me.....dosn't the TR6 gearbox,that I should have mentioned that I have in my 3 have a thicker flange? The car is in a frozen garage otherwise I'd go out and look and take measurements.

 

[TR3driver]

Er, yes. Unfortunately, I didn't record the bolt/stud lengths I used. But the bolts were standard hardware store lengths (in grade 8), except for the "dowel bolts" (which the TR6 used in place of the locating dowels). The dowel bolts & studs I made myself to suit.

 

[karls59tr]

Er, yes. Unfortunately, I didn't record the bolt/stud lengths I used. But the bolts were standard hardware store lengths (in grade 8), except for the "dowel bolts" (which the TR6 used in place of the locating dowels). The dowel bolts & studs I made myself to suit.

Thanks Randall I was going to ask what grade but now I know.

 

[TR3driver]

Grade 8 is certainly overkill; just what I had on hand. But I would buy at least Grade 5, since I don't necessarily trust the "ungraded" stuff from the hardware store. Some of it seems awfully soft/weak.

 

[PeterK]

You really have to watch all fasteners nowadays since much if not most is sourced overseas. Most grade 2-5 in HD and Lowe's is from China and I wouldn't use them in critical areas.

If you decode the letters on top of the bolt, you can trace the manufacturer. If there are not letters, it might mean that it's not US, don't know for sure but I avoid unmarked fasteners for the most part. These letters are cast into the bolt not the ink marks from HD and others.