Rear

[George Coleman]

Just looing for input! Has anyone found a suitable replacement for the ring gear bolts and washers for the Alpine rear end?

 

[pruyter]

Hi George,

just a few months I have replaced those bolts in the Alpine of my brother.
I bought this bolts in the UK and it concerns aerospace bolts NAS 1306-4.
The 06 means 3/8 inch diameter and the -4 means 1/4 inch of plain shank. I still had to shorten the threaded part of the bolts by about 0.1 inch.
I used red 262 Lock tite and reused the old washers. The old washers can be used because the torque wich was used to fasten them has taken out the kind of "plasticy" which caused the bolts to go loose.

Regards,

Peter

 

[Alpine66]

I've never had an Alpine rear axle apart, if I understand correctly you can't just use grade 8 bolts on the ring gear?
Or is it something with the threads and or bolt length?

 

[Ken Ellis]

I think the issue is not Grade 8 or not, it's fitment.

The 1/4" of shoulder is required to get a good uniform bearing for each bolt around the ring. Many store-bought Grade 8 bolts that short are threaded all the way to the head, which means the ring gear would be bearing on points of thread instead of a continuous surface.

While bolt strength is important, the main issue is the elimination of play.

The bolts called out above are both short, tough (which is sometimes better than hard), and have a short un-threaded segment at the head. All good, except they're slightly too long, and would bottom out. Can't stack up washers, so you have to trim. I used my milling machine, and they cut pretty easily. I did end up using hard flat washers, and red Loc-tite to finish out the repair. Pending install, though...

 

[hartmandm]

If the original bolts are in ok shape, any reason not to reuse them, instead of replacing them?

Mike

 

[Ken Ellis]

The ones I pulled had shiny areas on opposite sides of the non-threaded part, indicating movement, (and slightly undersized, ensuring it would happen again.) If they're uniform in 'patina', with good threads and heads, I would guess they're OK.

Although others do, I'm not sure I would re-use the washers with either bolts. They're kind of the instigators of it all...

 

[pruyter]

The original tab washers are to soft, they compress and allow the bolts to come loose. I would always re-use the old tab washers because they will already be "yielded" and become thinner and maybe workhardened.
When I took out the diff of the Alpine I found 4 bolts to be loosened, but they had not fallen between the gears because the same tab washers that caused them to be loose prevented them to fall between the gears.
That is why I, like others, re-used the old tab washers.

 

[Bill Blue]

The original tab washers are to soft, they compress and allow the bolts to come loose. I would always re-use the old tab washers because they will already be "yielded" and become thinner and maybe workhardened.
When I took out the diff of the Alpine I found 4 bolts to be loosened, but they had not fallen between the gears because the same tab washers that caused them to be loose prevented them to fall between the gears.
That is why I, like others, re-used the old tab washers.

If the soft washer had not failed in its duty, it would not be needed to keep the bolt from falling out.

I guess the lack of virtue is its own reward.

As I see the bolt/washer issue, the ability of the bolt to maintain clamping force is more important than its ability to physically prevent movement. The stock bolts shear when movement occurs.
Movement = shearing.
No movement = no shearing.

Bill

 

[George Coleman]

So far you have given me some good info, as for the reuse of the bolts Doug Jennings at Tiger auto said if they are shiny on one side you need new bolts. At this point it looks like a one inch bolt with a shoulder and cut them to length and run the thread up so to have the right thread length and the proper shoulder length. Looks like some machine work is in order, Would you reuse the washers? or use a split washer with lock tight?

 

[pruyter]

I agree with you Bill Blue and after using aerospace bolts and fasten them with Locktite 262 and no washers at all. Tab washers should not be needed. I did re-use them as a matter of special security and more so because it concerned not my Alpine but the one of my brother and in the case of a possible failure I was surely not interested in some negative comments like "you should have used the tab washers".

 

[Mike O'D]

Attached is a picture of my bolts/washers. There wasn't even a question of using them again!

Mike

 

[RootesRacer]

I agree with you Bill Blue and after using aerospace bolts and fasten them with Locktite 262 and no washers at all. Tab washers should not be needed. I did re-use them as a matter of special security and more so because it concerned not my Alpine but the one of my brother and in the case of a possible failure I was surely not interested in some negative comments like "you should have used the tab washers".

I wouldnt reuse the stock washers under any circumstance, they are dead soft and need to be in order to be able to deform them as that type of lock.
Its the deformation of the washer under stress that causes the failure, reuse is about the worst thing that can be done.

I would use a proper ground grade 8 washer and the loc-tite and never worry again.

 

[jumpinjan]

I agree to remove all locking plates.
Be careful not to use a thick washer, because thats less threads into the carrier. I don't use any washers, I just tighten & using the "red" (strongest) thread locking liquid. Either way is fine
Jan

 

[PROCRAFT]

If it was me I'd be using the AN/NAS bolts with a thin an washer and probably safety wire them!

 

[Alpine66]

I think the issue is not Grade 8 or not, it's fitment.

The 1/4" of shoulder is required to get a good uniform bearing for each bolt around the ring. Many store-bought Grade 8 bolts that short are threaded all the way to the head, which means the ring gear would be bearing on points of thread instead of a continuous surface.

While bolt strength is important, the main issue is the elimination of play.

The bolts called out above are both short, tough (which is sometimes better than hard), and have a short un-threaded segment at the head. All good, except they're slightly too long, and would bottom out. Can't stack up washers, so you have to trim. I used my milling machine, and they cut pretty easily. I did end up using hard flat washers, and red Loc-tite to finish out the repair. Pending install, though...

Good info, Thanks