Can someone tell me what, if any, the difference is between the rear axles on a 91 f-350 single rear wheel and an 89 f-350 dual rear wheel. Does the dually have the same axle and just the extra wheels? Or is the axle actually bigger? My 91 SRW has a GVWR of 9200 and my buddy's 89 dually is 10,000. Is the braking system different? Thanks for the help!

 

If I'm not mistaken, they're completely different axles.

The SRW is a Sterling 10.25" axle, and the DRW is a Dana 80.

 

I am not sure on a 91 I have an 86 with SRW and it is a Dana 80.

 

How doI find out what I have? Is there a sticker somewhere? Is the brake system the same on the dually. My lance camper is to heavy for the SRW and I would like to convert to the dually. I need to increase the GVWR not just add two more wheels.

 

All dually's from 80 up used the Dana 70 rear. They didn't start using the dana 80 rear til the SD. If any pre SD had the D80 it had to been swapped in or was a heavy utility truck.

your 91 will have the sterling 10.25 rearend and his 89 dually should have the D70.

Since your wanting to make the swap head to the wrecking yard and find a daully donner truck to rob the rearend and springs from. Besure It comes from daully that came from the factory with a bed and not a Cab & chassie they use narrower frames then a bedded truck. Since your truck is a F350 your braking system is the same used on the daullys. It'll all bolt right up.

 

Thanks for the info that really helps. One more thing. I have the 3.55 rear end in my current srw. How do I tell what the rear end is in a wrecking yard rear end? Is there a stamp or sticker? Thanks again!