Late AAM w/Discs to Replace HO52?

[bry593]

Anyone done or have info on this swap?

I am considering a 2001+, semi-float, 14-bolt, 9.5" ring, disc brake axle assembly as a replacement for my 4.10 HO52. The HO52 works fine, just the noise at 75 mph wears on me. I drive it about an hour a day at this speed and I'd like to reduce driver fatigue due to noise. It's not an issue at 50 mph, but 75 mph it does get annoying.

Yes, I know the HO52 is an excellent design and that GM redesigned it into the 14-bolt to save money (not increase durability). The problem is that a new ring and pinion are not available. When worn, you just have to live with the noise or swap it out.

Anyway, was thinking I might swap over to a modern axle. Obviously, will have 14mm studs and will need to adapt from SAE to metric brake line. Also will have to figure out the E-cables.

I don't see a need for a full 10.5 or 11.5 AAM. It's just a 3/4 ton and the semi-14 is rated at 5500 GAWR (HO52 rated at 5200). So should save some gas mileage and improve suspension response (reduce unsprung weight).

Will this axle be too wide? Anyone have pics of this axle installed on our trucks? I believe the HO52 is 65" WMS, and I've read that the 14-semi is 68" WMS (but I've not verified). Anyone know for certain?

[Richard]

I put a 2006 AAM 11.5 under the rear of my K10. IIRC it is the same WMS to WMS as the stock front Dana 44 and the new custom front Dana 60 I installed. Maybe + or - a 1/2". Been a while since I was at that stage.
Edit- Noticed the truck in your signature is a C20. Assuming 9.5, 10.5 and 11.5 are the same the rear axle width matches the front of my 4x4. The axle width will most likely be wider than your front track width. 4x4's have a wider track width in front. Cannot remember exact measurement of AAM is 68"-69"

[bry593]

Nice work on your truck. You are pretty serious about it.....

I've "read" that the 2001-2010? 1 ton (11.5" AAM) measures 65 wms. The 11.5 is easily identified by a damper ring on the input yoke.

Rumor is the 2001-2010? 3/4 ton (10.5" AAM) measures 68 wms. There is no damper on the input yoke.

Another story suggests the 2001-2010 light duty 3/4 ton (9.5" AAM Semi-Float) also measures 68". This unit is completely different from the two 14-bolts listed above. In addition to LD 3/4-ton, it was also used in Tahoes, Escalades, Suburbans and other car-trucks. This is the one I'm hoping will work in my truck. I don't need a 400-500lb axle. That'd just be silly....

The above applies to single wheel axles, no duals and no vans. Vans are supposedly about 70" wms. Way too wide.

To be certain, I'll need to measure myself. I suppose I'll build some sort of jig so I can measure several different axles quickly at the salvage yard. I'm thinking a wooden 1x2x12" with two 9/16" holes and two sheet metal tabs to catch on the lugbolt threads. I can then pull a tape from one side to the other and get a fairly accurate WMS.

I'll report back when I get around to it.