Bell housing to engine bolt factory assy sequence

[Steve L.]

On an M20 4 spd bellhousing there are 6 bolts holding the bell housing to the engine. These must be painted orange along with the bellhousing and engine.


However, the one bellhousing bolt(lower right side) that holds the positive battery cable clamp and grnd wire(one some cars) must have been assembled after the body drop since this clamp must be opened up to pass the cable thru and then clamped by the bolt afterwards. It can't be done while bolted.

So is this bolt different than the other 6 bolts. I don't imagine the factory would have removed the bolt, then added the battery cable clamp.

If this bolt was vacant during engine painting, should this one bolt be unpainted since it would have been added after the body drop? Also, would this one belt be a different head?

[Terry M.]

Re: Bell housing to engine bolt factory assy sequence

On an M20 4 spd bellhousing there are 6 bolts holding the bell housing to the engine. These must be painted orange along with the bellhousing and engine.


However, the one bellhousing bolt(lower right side) that holds the positive battery cable clamp and grnd wire(one some cars) must have been assembled after the body drop since this clamp must be opened up to pass the cable thru and then clamped by the bolt afterwards. It can't be done while bolted.

So is this bolt different than the other 6 bolts. I don't imagine the factory would have removed the bolt, then added the battery cable clamp.

If this bolt was vacant during engine painting, should this one bolt be unpainted since it would have been added after the body drop? Also, would this one belt be a different head?

Actually, I believe they did remove the bolt to attach that clamp. The question is did they replace the bolt they removed with one that was longer to accommodate the added thickness of the clamp. If your copy of the AIM (Assembly Instruction Manual) shows a part number for that bolt, then the bolt installed at St Louis was longer and unpainted. My 1972 AIM shows they reused the bolt that was supplied with the engine, but you need to check the AIM for your year of production as this sort of detail could have changed from time to time.

[Peter S.]

Re: Bell housing to engine bolt factory assy sequence

Terry, Steve,

It appears for at least '69-'72 that the bolt was removed and replaced. My question is: was the bolt from Flint different at this location? A member on the corvetteforum posted a picture of his '70 LT-1 bolt and showed a grade 8 bolt for the cable clamp. He noted another bolt was exactly the same at "the lower left."

I noticed, too, that I have a grade 8 flanged bolt at the cable clamp and also have a grade 8 flanged bolt at the clutch fork boot.

In total, I have 4-grade 5 bolts and 2-grade 8 bolts.

[Alan S.]

Re: Bell housing to engine bolt factory assy sequence

Hi,
On my 71 the bell housing bolts are the originals and are all the same. A "M' head mark with 3 slashes indicating a grade 5 bolt.
The 71 AIM UPC12, Sheet A12 indicates in the drawing that the bolt that holds the clip is the one that came from Flint. There's a note in parenthisis with a line leading to the bolt … (ENGINE), and then a small square symbol that's 1/2 white and half black. There's no item listing on the page for another bolt to be used at that location.
There's a similar note and symbol at the coil mounting bracket page, UPC6, Sheet B6, where again a bolt that came with the engine from Flint is reused, but the other bolt for the bracket is changed. On this sheet there's an item #/part # for the bolt that's changed. I think I'm saying that accurately … the engine ends up with one orange bolt, and one unpainted bolt, mounting the bracket.
Regards,
Alan

Hi Peter and Russ,
I corrected my bolt grade error.
I'll blame it on my wife…had to stop in the middle to help make the cranberry relish with a manual grinder that must be approaching 85 years old. I believe the wing nut that holds the 'toothed wheel' on the shaft is original and therefore must be worth a fortune because I'm sure the replacements are too thick!

[Peter S.]

[Russ S.]

Re: Bell housing to engine bolt factory assy sequence

Three slashes is a grade 5 bolt.

[Alan S.]

Re: Bell housing to engine bolt factory assy sequence

Hi Peter,
I did get it and read it but haven't replied yet.
I've been trying to do some manganese phosphate plating today with a new ss container and heater that has taken a bit of time to get running.
It's ALL fun!
Happy Thanksgiving!
We certainly have a wide range of things to be thankful for!
Regards,
Alan