differential cover bolt

[35chevcoupe]

Anyone know if the top differential cover bolt that holds the brake hose bracket on is the same length as the rest of the bolts or is it suppose to be a little longer ?
If I recall I thought I remember seeing the top center bolt a little bit longer .

[cwmcobra]

All the same length as far as I recall. 

Chuck

[schlepcar]

I think they are all 3/4 "shoulder" style bolts except the one you are talking about. That one was a tad longer and a regular grade 5 head.  I am not sure if that is 100 % correct,but all the originals I have seen were as described. This is getting pretty fussy for a guy that would take out a twelve bolt for a ten....I think we would be safe to say that you are trying to do it "right".

[Mark Ascher]

....I think we would be safe to say that you are trying to do it "right".

Dan,

John is doing an outstanding job.

Mark

[35chevcoupe]

I think they are all 3/4 "shoulder" style bolts except the one you are talking about. That one was a tad longer and a regular grade 5 head.  I am not sure if that is 100 % correct,but all the originals I have seen were as described. This is getting pretty fussy for a guy that would take out a twelve bolt for a ten....I think we would be safe to say that you are trying to do it "right".

Dan ,
Thats what I was thinking to , that the one bolt was like an 1/8 " longer . It seems like if I remember right it was,t threaded all the way up either .
 Oh well I,m not going to waste time trying to find one it was just a part of my ( whats left of it ) long term memory kicking in .
Ordered a set from the parts place .

[cwmcobra]

John,

I still have the unassembled axle in my parts car.  I'll take that bolt out and send it to you.  Or, you can have them all if you would like.

Chuck

[GS66]

John, you can have the bolts from my green GS too.

[cwmcobra]

John,

Below are a couple of pictures that confirm (to me....) that the differential cover bolts are all the same length.  The first one is from the fastener preparation that I did on my restoration project and shows all bolts as 5/16" diameter by 1" long.

The second picture is of two bolts that i just removed from the differential on my parts car.  65 Skylark, 10-bolt non-posi, but I'm sure that doesn't make any difference.  The bolt on the right in the picture is the top one that secures the bracket for the brake distribution block.  You can see that it is the same length as the one on the left, that was located next to the top bolt.  5/16" diameter by about 15/16" long (probably spec'ed as a 1" length bolt).

There don't appear to be any head markings on the bolts that I took out of my restoration.  But one of the bolts that I just removed from the parts car has "TR" raised in the center of the head.

Chuck

[35chevcoupe]

 Chuck ,   
thanks for checking , I,m sure they aren,t any different from a GS to a skylark .  The cars I remember being different may have had a thicker bracket on them .

[Rollaround]

John, I would have liked to contribute but my bolt didn't cooperate.   It snapped off right at the base, I had to drill and retap it.  Just one of those slow ya down things. 

Chuck, note all of the bolts do have grade stamping marks on the heads.  Kansas City car, where the differencal was made I don't know.  Suggesting once again the production standard was not always standardized.     

[schlepcar]

Luck like mine...just snapped off a couple of those on an old jeep axle we are working on. It it goes too easy something is wrong Kevin.

[cwmcobra]

Kevin,

I hate when that happens!  Actually, I was somewhat surprised that I got the two bolts out of my parts car this afternoon.  The lower one came loose pretty easily.  The top one was stubborn, turning pretty tightly until near the end of the threads.

I looked more closely at my picture of the blasted bolts and am pretty sure I see the vestiges of radial grade markings.  They were a bit corroded, so it doesn't show up real well.  I'll try to remember to get underneath the car tomorrow and see if the markings show up better after the bolts were plated.

Here's hoping that the bolt breakin' bad luck is behind you!

 

Chuck