External lockouts on 3/4 ton hubs?

[Big Blzn]

My question:

Are there specific years that the 8 lug 3/4 ton wheel hubs came on that had the external lockouts, IE. '77-'91 and they would have had the bigger spindles?

And the 8 lug 3/4 ton wheel hubs that have the internal lockouts came on the '73-76 D44's with the smaller spindles?

Do the External lockouts only come on specifc year 3/4 ton D44 or 10bolts?

Any help or clarification would be helpful. Thanks fellas.

Hoby

 

[bp71k5]

I don't know the years, but I saw a factory 3/4 ton D44 with the big external locking hubs. It was supposed to have come from a 69-72 k5. Is that what you're asking?

 

[thatK30guy]

External hubs on D44's ran up to '76. In '77, GM began the internal hubs along with the different spindle size bearings.

You have the internal and external switched around on the years. External is '76 and older. Internal is '77 and newer. This holds true for both 1/2 and 3/4 ton.

The externals came from D44's but they will bolt easily to 10 bolt fronts as long as the correct spindle is used.

 

[Big Blzn]

Thanks for chiming in Brian. Since I am going to buy your axle I'm selling my 8 lug hubs that are external lockouts, I have another member interested in them but he wants to know if they will fit his '77-'91 blazer/truck. I just don't know what the hubs I have are out of. And if they are the smaller or larger spindles. I don't know just by looking at the bearings if they are the larger or smaller spindles. do yo know how I would be able to tell?

 

[bp71k5]

I have a set of both large and small bearing spindles if you want to compare. (FYI: You're new axle has the larger bearing spindles.)

When I measured them, the only difference was the inner bearing shoulder was larger on the later ones. I got them from a 79-ish suburban.

One easy way to tell if you have the larger spindles is whether you can find inner bearings for them. If you can find them easily, they are likely the larger\newer ones. Try and see if a parts store will let you slide a bearing race over it to check.

Edit: If I learned this correctly, the hubs are supposed to work on either size spindle. The bearings and spindle are what are different so it shouldn't matter what hubs you have.

 

[Big Blzn]

I just measured each of the inner and outer bearings of the 8 lug hubs and here is what I have.

Inside bearing surface of each bearing that contacts the spindles are:

Outer bearing (next to spindle nut) diameter is 1.623 give or take.

Inner bearing (nest to seal) diameter is 1.997 - 2.0 give or take.

Brian, what you said above is that the hubs are the same for all years it is just the size of the bearings and races and the spindles, right?

 

[bp71k5]

Brian, what you said above is that the hubs are the same for all years it is just the size of the bearings and races and the spindles, right?

That's what I understand, except the races should be the same since they press into the hub.

 

[jamber2541]

just an FYI... the external hubs us the smaller bearings, internal hubs have the larger ones

 

[bp71k5]

Outer bearing (next to spindle nut) diameter is 1.623 give or take.

This matches both the big bearing and small bearing spindles I have that both came with internal locking hubs.

Inner bearing (nest to seal) diameter is 1.997 - 2.0 give or take.

That number matches the later model 3/4 ton bearing spindle I got from a 79 suburban with internal hubs. On the smaller spindle I have from my 71 k5, this diameter is about 1/4" smaller. (The grease was too messy to get an accurate measurement with my clean micrometer.)

the external hubs us the smaller bearings, internal hubs have the larger ones

In case there's confusion over what I mean by small and large bearings, I'm calling the smaller bearing the one with the smaller diameter hole in the center. Since I only have the two versions of internal hub spindles, I can't say what the details for external hubs are.

 

[bp71k5]

In case it helps, the smaller bearings still appear to be available at Kragen's, although your measurements appear to be for the later model bearings.

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=SKF&MfrPartNumber=BR37&PartType=184&PTSet=A

 

[thatK30guy]

Another thing to learn/know about the two different spindles and some parts stores will ask you which you have:

First design

Second design

First denotes the axles up to '76.

Second denotes axles from '77 on up.

 

[4X4HIGH]

I just measured each of the inner and outer bearings of the 8 lug hubs and here is what I have.

Inside bearing surface of each bearing that contacts the spindles are:

Outer bearing (next to spindle nut) diameter is 1.623 give or take.

Inner bearing (nest to seal) diameter is 1.997 - 2.0 give or take.

Brian, what you said above is that the hubs are the same for all years it is just the size of the bearings and races and the spindles, right?

The wheel hubs are different as well as the inner bearing and spindles.

Ok, external hubs are 69-mid 76 and internal hubs are mid 76-87 (91 sub and blazer). There is a design change which was the inner bearing changed from a 1.75" ID to 2" ID and was mid year 1976 and this required a different spindle to accept this bearing. So, 1st design was 69-mid 76 and 2nd design was mid 76-87 (91) You cannot install 2nd design inner bearings into a 1st design wheel hub (the race is different size on the OD). If you want to install external lock outs onto a mid 76 and later axle you must change the spindles also in order to do it.

 

[Big Blzn]

The wheel hubs are different as well as the inner bearing and spindles.

Ok, external hubs are 69-mid 76 and internal hubs are mid 76-87 (91 sub and blazer). There is a design change which was the inner bearing changed from a 1.75" ID to 2" ID and was mid year 1976 and this required a different spindle to accept this bearing. So, 1st design was 69-mid 76 and 2nd design was mid 76-87 (91) You cannot install 2nd design inner bearings into a 1st design wheel hub (the race is different size on the OD). If you want to install external lock outs onto a mid 76 and later axle you must change the spindles also in order to do it.

Thanks for replying Scott. OK, so I think I got it. Double check me though.

Since my inner bearings measured 1.977-2.020 + or - I, or the guy I'm selling the hubs to would need the larger spindles, right?

 

[4X4HIGH]

The bearing diameter you have needs the larger spindles, however those would be internal locking hubs not external.

Not to sound like an a** but do you know what an external looks like?

 

[Big Blzn]

The bearing diameter you have needs the larger spindles, however those would be internal locking hubs not external.

Not to sound like an a** but do you know what an external looks like?

These are mine I have FS. If they aren't external then I really have NO idea. And yes, to get the proper measurement of the inner bearings inside diameter that measured 1.977 with my micrometers I removed the inner seal (oil) and pulled the bearing out to make sure of measurement.

EDIT: So, now what do you think????

 

[4X4HIGH]

These are mine I have FS. If they aren't external then I really have NO idea. And yes, to get the proper measurement of the inner bearings inside diameter that measured 1.977 with my micrometers I removed the inner seal (oil) and pulled the bearing out to make sure of measurement.

EDIT: So, now what do you think????

View attachment 76959

Well, that contradicts everything i've ever learned about these trucks. The only explanation about those external hubs having the larger bearing could be that the bearings on the external style are interchangable whereas i know for a fact the internal style are not.

At any rate, the buyer would need the larger spindles 77-up since the inner bearings have a 2" ID.

 

[Big Blzn]

Well, that contradicts everything i've ever learned about these trucks. The only explanation about those external hubs having the larger bearing could be that the bearings on the external style are interchangable whereas i know for a fact the internal style are not.

At any rate, the buyer would need the larger spindles 77-up since the inner bearings have a 2" ID.

Thanks fellas. Looks like I actually learned a lot on this thread. Funny how I guess the simplest questions can turn out to be so confusing. Looks like I have my answer and I appreciate everyones brainstorming and answers they gave. You fellas are standup for bearing (pun intended) with this question.