Dually conversion thoughts

[cybrfire]

OK, my crewcab will undergo its transformation sometime in August so I'm gathering parts. Have most of the stuff now.

The rear axle, Right now its SRW so its WMS - WMS is 67.5". A dually is 72".

So if I leave the SRW axle in it and go with dually rims and my little bit wider tires I can gain (narrower) 2.25" on each side. Less chance of the tires sticking out to far. I'm pretty certain I'll have to use spacers between the dually rims so I'm thinking it'd be nice to keep things as narrow as possible.

Any thoughts on inner fender clearance? Brake issues?

Inner fender clearance is a simple fix. I wouldn't think the rims would hit brakes. Probably do a disc conversion. Can't think of much else that would come up. Maybe I'll find another axle so I can throw this stuff on there ahead of time. Just in case.

 

[CammoK5]

I think the problem with dually rims on a srw axle is the tire/wheel rubbing the frame. That's why dually axles are longer. Theres a company who makes dually conversion kits that dont require a new axle. Instead they use a spacer that bolts onto you existing hubs like a wheel would. This spacer then has longer studs that your dually wheels bolt to. It spaces the wheels out far enough from the frame not to rub and provides longer studs to safely mount the dually wheels onto.
This is how Ford made 4x4 dually F350's in the mid and late 90's. They never made one from the factory, they were all converted then sold at the dealer like that. I'm not sure just how safe it is or how well they hold up to heavy loads though.

Danged if I cant remember the name of that company. Anyways, they sell the conversions for all types of trucks. Includes rear adapters, front adapters, fiberglass fenders, wheels, ext. Kinda pricey though, I think out the door painted and all it's around 4K.

 

[jekbrown]

dually rear ends have got to be a dime a dozen... everyone in the 4x4 crowd wants srw. It ought to be possible to find a guy with a pair of 1 ton dually axles who will swap ya rear axles...shouldn't it?

j

 

[nvrenuf]

ArrowCraft is one company that akes adapters/kits, I have a set of their rear adapters.

Cybrfire, how big of a tire are you planning on running? I agree with CammoK5 that rubbing the rear frame/inner wheel well may be an issue. TARussell may be able shed some light on this as he had a factory dually that he put 12.50x38's on. He originally bought the spacers that I now have, he had to run them between the rear wheels to prevent tire rubbing. His set up used a D70HD though so he had no issues with rubbing the frame/fender wells.

 

[nvrenuf]

Here's Tom's (TARussell) old truck -

 

[conoverbandit]

Hey Y'all,
Thought I'd put my .02 in on this. I have a 71 GMC 3/4 ton,2by truck. We converted it into dually long before the front ever was. Here's how we did it: On ours we had to set the fender wells in 3in. on each side and had a plate made to "fill in the gap". We cut the inner wheel well (the one in the bed) and also cut 3inches out of the bed. Bolted every thing back together.We had plenty of clearance from the inner most dually wheel.No rubbing the springs,or anything like that. The outter wheel stuck out about 2-3in toward out side. We used a set of jeep fender flares to go on the out side to cover this area. No problems. It still has the factory D-60 rear in under it, been hauling pretty heavy loads for years with no problems. I did how ever have to lift the bed 2in. so when we loaded'er down in a curve the tires would rub, depanding on the load. I can get you pic's if you want. Hope this helps,

Wayne

 

[kennyw]

I think the problem with dually rims on a srw axle is the tire/wheel rubbing the frame. That's why dually axles are longer.

No, the wider axle is to put the inner tire in the same place as a SRW with the pickup bed. The cab and chassis 1 ton duallys actually had a narrower axle (63" wms to wms) that put the tire close up to the spring and frame than the SRW axle will.

You can bolt on the dually rims to a SRW without hitting the brakes, springs or frame. You may have to make the inner wheelwell bigger, but probably not. I've seen many trucks with SRW front tires and Duals thrown on the back without any extra work. Of course most of those seem to be Fords for some reason.

 

[cybrfire]

I don't think the inner dually rim/tire would contact the frame or springs. I kinda figured it'd contact the wheel well but like I said, that's an easy fix. I just happen to have a set of old wheel wells layin' in the junk pile.

Around here it's not so easy to come up with a dually rear for some reason. I have 6 SRW 14 bolts but haven't come across a DRW yet.

However, putting a wider axle in doesn't help keep things narrow considering the wider tires and wheel spacers.

Thanks for the input every body. Sometime in August all this will get underway and I'll be posting up some pics.

 

[u2slow]

I would be weary on the fitment of 16" DRW wheels on the SRW axle and brakes....

The DRW drums are more cone-shaped, presumably for wheel clearance. Larger wheels - like 19.5s - may be one solution.

FWIW, I measured up a set of old 18" DRW split-rims with 7.50x18 rubber for my Suburban. I would have had less than 1/2" clearance on the inside.