Front Axle / Front Suspension: Kind of bolts?

[Hawklover]

The four 3/8-24 bolts that hold the bellcrank housing, can anyone tell me what kind of bolts they are?? .....and the grade of the bolt??

[52 Ragtop]

"most likely" a grade 5, If you are replacing, I'd go with grade 8, better to over kill and be safe, than be sorry.

Jim

[Skybolt]

According to most torque specs Grade 8 is about the right grade for Studebaker's Shop Manual torque specs of 40-45 ft-lbs. for 3/8 x 24. So it's not overkill it's the right grade.

Len

[studebakerkid]

By law they have to be grade five or better. I will be replacing mine with grade 8 and using nyloc nuts.

[Hawklover]

Jim, ok I know the grade to purchase, but what kind of bolt, are they hex head, partially threaded, or stove/machine bolts?

"most likely" a grade 5, If you are replacing, I'd go with grade 8, better to over kill and be safe, than be sorry.

Jim

[Hawklover]

"Kid", the shop that only replaced two of the four utilized two Nylocs........and the nylon material is somewhat disintegrated:-(

By law they have to be grade five or better. I will be replacing mine with grade 8 and using nyloc nuts.

[Hawklover]

Gents, two of the bolts call for 4 inches, the other two, inch and a quarter.

In what position are the longer bolts?......front holes or rear?

Many continued thanks!

[sweetolbob]

Gents, two of the bolts call for 4 inches, the other two, inch and a quarter.

In what position are the longer bolts?......front holes or rear?

Many continued thanks!

HL

The bolt position should be evident when you try to replace them. The longer ones are necessary to pass through the front crossmember while the shorter ones only go through the crossmember lip.

I'm with SK on the grade 8 bolts. I use them almost everywhere as they are reasonably priced at TSC. I buy in bulk and have a ton of them around. The pictures in the other post show I also like nyloc nuts where appropriate.

If you want fine thread, they are generally more difficult to come by around here. Probably not necessary in this application but if you need fine thread in the future, look for a Fastenal store or equivalent. We have one here and they carry all of those more difficult to find hardware.

Type is just the good ol' hex headed bolts as in the other post with pictures.

Bob

[Hawklover]

Bob continued thanks.......as to the washers.......go with SAE as opposed to plain jane flat?...and should I torque to 40-45 ft lbs?

HL

The bolt position should be evident when you try to replace them. The longer ones are necessary to pass through the front crossmember while the shorter ones only go through the crossmember lip.

I'm with SK on the grade 8 bolts. I use them almost everywhere as they are reasonably priced at TSC. I buy in bulk and have a ton of them around. The pictures in the other post show I also like nyloc nuts where appropriate.

If you want fine thread, they are generally more difficult to come by around here. Probably not necessary in this application but if you need fine thread in the future, look for a Fastenal store or equivalent. We have one here and they carry all of those more difficult to find hardware.

Type is just the good ol' hex headed bolts as in the other post with pictures.

Bob

[sweetolbob]

Bob continued thanks.......as to the washers.......go with SAE as opposed to plain jane flat?...and should I torque to 40-45 ft lbs?

Use the grade 8 washers that fit the bolts. They are usually a bit smaller OD than the lesser rated ones and that may be a factor in fit in the lip area. As far as torque, I think that was mentioned before for 3/8" bolts but I'd check the manual to see if it's specified there.

Also remember that the grade rating is only as high as the lowest rated component. A 5 nut on an 8 bolt isn't grade 8 anymore.

Here's Fastenal's chart for bolt torque but there can be circumstances that the service manual may call for less due to other circumstances.

http://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf

Bob

OOPs, just read above and see Skybolt says the manual is 40-45 lb-ft so Avanti.

[Hawklover]

Thanks Bob!.........Is there a reason you use Nylocs?......... or should I go with nut/lock washer?

[Skybolt]

Jim, ok I know the grade to purchase, but what kind of bolt, are they hex head, partially threaded, or stove/machine bolts?

Get a Chassis parts book and all this information is there, although it takes some getting used to the terminology and sometimes it's a back and forth from page to page to get all the information required.

You want hex head bolts. Grade 8. Take the old ones and match the thread depth.

Another thing to remember is that a hex screw can look similar in dimensions to a hex bolt but are finished to a tighter tolerance. An example is the 5 fasteners used on the center pin you are asking about. The four that fasten it to the crossmember are bolts but the one that holds the bellcrank to it specified for a bolt or a screw, depending on its application. A screw for cars with Bendix power steering, a bolt for manual steering applications. The engineers must have specified a tighter tolerance for power steering cars. Plate 12-3, and page 1207 regarding part numbers, under 1209-1A: G454962 is a "bolt" but G454961 is a "screw". How many of us knew the difference, except for maybe for the difference in length?

http://www.portlandbolt.com/technica...ex-cap-screws/ this is a good explination of each type.


Len

[sweetolbob]

Thanks Bob!.........Is there a reason you use Nylocs?......... or should I go with nut/lock washer?

Probably just whatever you like, the originals on mine were nut/washer but I'm a nyloc fan. The downside of Nylocs is it's difficult around here to find higher grade Nylocs. I have a selection so I use 'em. Just don't weld near them, it kinda destroys their holding power.

[JoeHall]

Agree with grade 8. Also, if the manual calls for fine thread, do not substitute with standard/coarse thread. The same torque will result in different pull. Put another way, the fine threaded bolt will pull tighter than standard, at same measured torque on the bolt/not head.

[Hawklover]

Bob I just noticed that the parts book only delineates two plain washers......do these go under the shorter bolts??

Probably just whatever you like, the originals on mine were nut/washer but I'm a nyloc fan. The downside of Nylocs is it's difficult around here to find higher grade Nylocs. I have a selection so I use 'em. Just don't weld near them, it kinda destroys their holding power.