14 bolt question

[Drewbee]

Hey went to put my new lift in the truck I'm building and it is not measuring up. I was told a 14 bolt is a straightforward swap except for moving the shock mount. Could someone tell me what 14 bolt I have?

[Drewbee]

Second pic

[Drewbee]

Third pic

[whitedog76]

Offhand, it looks like a 88 and newer axle.

I would say 3/4 ton truck or van.

[Drewbee]

That's what I thought as well, but I guess these are not bolt in and I will have to move the spring perches?

[Bigdav160]

It certainly looks wider... a lot wider than mine

[slotard]

What's the width perch to perch? On my '73 C20 it's around 43" center to center (measured sloppily, could be off an inch).

[Drewbee]

I'll try to get out there and measure the perches from center. I do remember it being the new style. I was told the fins on the pumpkin are a give away. But I also thought it was still a bolt in. Minus the dust, I had rebuilt the axle and painted it. Now it looks like I'll have to move the perches inward. But I'd like more people to chime in and verify that it is a 14 bolt. The hubs I took off were srw and it maybe a stupid question but I'd rather ask for hen not ask.

[Mr. 250r]

That is an AAM full floater. 3in wider than the corporate 14 bolt full floater, or 1.5in on each side. Comes from the factory with a 1410 u joint which is really nice. You will have to move spring perches and shock mounts, the shock mounts are longer than a corporate 14 bolt and possibly on the wrong side i can't remember but doesn't matter because they will need moved anyways they are also angled. Not sure if your truck is 4wd or not but if it was your rear axle would match your front axle width as we know front axles are wider from the factory than rear this fixes the "dog walking" look on the road but there's always the controversy of how the front is supposed to be wider but i am no engineer so i won't go into that.

Finned 14 bolt housings came in i believe in 1988 along with slide off drums, my 89 has a finned housing i like how it looks personally so you can't just go off the fins themselves, a dead giveaway is the bump stop plate on the axle and disc brakes.

Good axle.

[andrewmp6]

Being its a finned 14 bolt its from the 90s,A AAM would have had disc brakes on it and he has drums.

[whitedog76]

2003 and newer vans had disc brakes and trucks started around 99/2000.

Looking at the spindle to backing plater distance, along with the overall width, I'm going to say its from a 2002 and earlier van.

[Mr. 250r]

I didn't even think to look at the brakes my bad lol but the only reason i didn't think it was an early 90s axle was because that bump stop plate i didn't think they had that i thought it came on the new body style 99 and up because the frame had been widened allowing room for that plate as far as van axles i couldn't tell you

[Drewbee]

Yes that's correct it does have drum brakes. So I assume it's a 90s 14 bolt not an AAM? But I'll still have to move the spring perches and shock mounts.

[whitedog76]

What are you putting the 14 bolt under?

BTW, If you want to narrow it up a bit, you can use dually hubs or Eaton hubs, and convert it to disc brakes.

[Drewbee]

I'm putting it under a 1971 k10. I thought it was bolt in basically but from what I gather its a newer 14 bolt from the 90s and not an AAM, correct?

[b454rat]

Pull the cover and look for the date code. I'd say early to mid 90s. I have had 2 trucks, 1 88 and 1 89 and they had Dana 70s in them. I replaced the 89 with a 14 bolt from an 93 3/4 ton. Not sure why one axle got slip drums when others were pressed. I have a van axle from an 02 3500 SRW, slip on drums.

[Matt72blaze]

that's from a 1-ton van...i have one under my burb, but it's from a mid '70's van. the original spring perch is in the same location though.

[andrewmp6]

The AAM started in 01 and was disc brakes only,You have a 14 bolt from the 90s not sure what its from with out knowing how wide it is.It could even be a van one those are normally wider then a pickup one.

[Bigdav160]

I always find this confusing. IIRC, American Axle always built the 14 bolt. They were spun off as a separate company in the early 1990's. Dodge trucks started using american Axle 14 bolts in 2003. Prior they were using Dana's in the HD trucks.

But the GM guys don't call the 14 bolt a AAM until it went to a 11.5" gear. <shrug>

[mrolds88]

Gm went to the slide on drums in 96. That also has the bigger pinion bearing in it too.

[Drewbee]

Here are some more pictures of the mystery 14 bolt. The axle is about 53 from backing plate to backing plate, and then the drums are about 6 and 1/4. That would put the overall width of at around 65. I think I'm not accounting for something because a srw axle should be 67.5". I also took a picture of one of the axle shafts.

[Drewbee]

Backing plate to backing plate

[Drewbee]

Srw drum height

[Drewbee]

Axle shaft

[Axe]

Did you get it out of a cab and chassis or dually,van or single wheel 1ton. The cab and chassis will be narrower than the others. But they only made 2 widths and one can be changed to the other, depending on what wms to wms you want.