OBS 05+ axle swap

jjsalz · Jul 7, 2016

Hey guys, I'm about to pull the trigger on a 2006 rolling chassis to perform a front and rear axle swap into my 97 OBS F250. Before I do I want to make sure I get my ducks in a row and know what else is needed. I've read on several forums it's mostly bolt on, I've also read it's expensive, also that the brake system will need attention (hydroboost conversion), special adapter fittings to fit the super duty calipers, can't use original OBS hangers in the rear, etc. etc.

So with that said, can anybody share any experiences? I'm budget minded and I want to know what I'll be looking at in a rough total $ amount in extra expenses. The only reason I'm looking into the 05+ swap is because I can get the entire rolling chassis for $900. I was originally just planning on getting an 86-97 D60 and swap the TTB.

Thanks a lot in advance! I can't tell you all how much I've learned already from powerstrokearmy.com and I really appreciate it

Lt.Dan · Jul 7, 2016

I am also interested, as i have a 96 F350 that i want to convert to 4x4, with the 05+ chassis.

ja_cain · Jul 8, 2016

Cool project! Definitely going to keep an eye on this thread. I want to get an OBS for my oldest daughter and it would be cool to swap in the nicer front and rear. Good luck!

78f100 · Jul 8, 2016

Here is a good thread on it if you haven't seen it yet. I plan to do this to my 95 one day.
http://www.powerstrokearmy.com/forums/showthread.php?t=9303&showall=1

ja_cain · Jul 9, 2016

78f100 said:
Here is a good thread on it if you haven't seen it yet. I plan to do this to my 95 one day.
http://www.powerstrokearmy.com/forums/showthread.php?t=9303&showall=1

That's an epic thread. I remember looking through it before. Thanks for posting it up!

78f100 · Jul 9, 2016

ja_cain said:
That's an epic thread. I remember looking through it before. Thanks for posting it up!

It's saved as a favorite on my phone....

Powerstroke Racer · Jul 10, 2016

jjsalz said:
Hey guys, I'm about to pull the trigger on a 2006 rolling chassis to perform a front and rear axle swap into my 97 OBS F250. Before I do I want to make sure I get my ducks in a row and know what else is needed. I've read on several forums it's mostly bolt on, I've also read it's expensive, also that the brake system will need attention (hydroboost conversion), special adapter fittings to fit the super duty calipers, can't use original OBS hangers in the rear, etc. etc.

So with that said, can anybody share any experiences? I'm budget minded and I want to know what I'll be looking at in a rough total $ amount in extra expenses. The only reason I'm looking into the 05+ swap is because I can get the entire rolling chassis for $900. I was originally just planning on getting an 86-97 D60 and swap the TTB.

Thanks a lot in advance! I can't tell you all how much I've learned already from powerstrokearmy.com and I really appreciate it

Do you have the steering box still on chassis?

jjsalz · Jul 10, 2016

Powerstroke Racer said:
Do you have the steering box still on chassis?

I do not know for certain if is still on the chassis, from reading the other thread that was linked above it looks like the steering box will also be an issue. Do you think it would be easier to swap in the Super Duty steering box or retrofit the setup to my OBS? Thanks everyone for the input I really appreciate this! I haven't bought the chassis yet because I'm pretty much torn right down the middle between doing the 05+ swap or the kingpin D60 front only.

Powerstroke Racer · Jul 10, 2016

jjsalz said:
I do not know for certain if is still on the chassis, from reading the other thread that was linked above it looks like the steering box will also be an issue. Do you think it would be easier to swap in the Super Duty steering box or retrofit the setup to my OBS? Thanks everyone for the input I really appreciate this! I haven't bought the chassis yet because I'm pretty much torn right down the middle between doing the 05+ swap or the kingpin D60 front only.

Much easier mechanical wise to use the 05 steering box

jjsalz · Jul 10, 2016

Powerstroke Racer said:
Much easier mechanical wise to use the 05 steering box

Ok, thanks. I take it you have done this conversion before? Are these newer axles better serviceability-wise or would I be stepping backward in that direction compared to the TTB? I also want to make sure that I'm setting myself up for smooth maintenance

Powerstroke Racer · Jul 10, 2016

jjsalz said:
Ok, thanks. I take it you have done this conversion before? Are these newer axles better serviceability-wise or would I be stepping backward in that direction compared to the TTB? I also want to make sure that I'm setting myself up for smooth maintenance

Yes I did my bronco back in 2008 When I put a 7.3 in it, I would not be too concerned about serviceability, if unit bearing goes out simply replace it. 05 up are virtually maintenance free, just a few grease fittings in steering other wise just drive.

jjsalz · Jul 10, 2016

Powerstroke Racer said:
Yes I did my bronco back in 2008 When I put a 7.3 in it, I would not be too concerned about serviceability, if unit bearing goes out simply replace it. 05 up are virtually maintenance free, just a few grease fittings in steering other wise just drive.

Ok, well that's good to hear. Unit bearings are very straightforward. I'm wondering a little bit more about the steering box, and the brake system. I know you did it to a Bronco but do you think my brake system will need any modifications? Like adapter fittings? How will my OBS brake system hold up to the newer calipers all around and disk brakes in the rear? As far as the steering box goes do you think I'll just be able to bolt it right up? Thanks again

Lt.Dan · Jul 10, 2016

Very good info here. Im also curious about the steering box, what about the OBS one wont work? And does the 05+ box bolt right up, and what about the steering column shaft? Does it mate up just normal?

Powerstroke Racer · Jul 11, 2016

jjsalz said:
Ok, well that's good to hear. Unit bearings are very straightforward. I'm wondering a little bit more about the steering box, and the brake system. I know you did it to a Bronco but do you think my brake system will need any modifications? Like adapter fittings? How will my OBS brake system hold up to the newer calipers all around and disk brakes in the rear? As far as the steering box goes do you think I'll just be able to bolt it right up? Thanks again

You can try the vacuum brakes the way it comes from the factory since it is already there and see how you like it, I did hydro boost because I used a 2000 engine and had no vacuum pump. The gear box will bolt right in but it is a larger diameter bolt 13mm iirc, I used 6.0 psd head bolts and machined spacers, you will need to drill the frame spacers to the larger size, I also used the brake lines and all from the SD chassis. There is also a frame width difference between the OBS and SD chassis of 3/4, some just bolt everything together and let the rubber take up the 3/8 per side difference but I made spacers for the from arm brackets and cut the perches on the rear axle since I had to roll the pinion and used the factory spring mounts.

Lt.Dan said:
Very good info here. Im also curious about the steering box, what about the OBS one won’t work? And does the 05+ box bolt right up, and what about the steering column shaft? Does it mate up just normal?

People use the obs gear box but pitman arm needs to be reamed, my thoughts were that if I use all 05 SD stuff and I need a lift or parts replacement on the side of the road I can use factory parts available at any auto parts store.

morefuel · Jul 12, 2016

I personally think the vacuum brakes work wonderful, to me they seem to brake very good and are nice and firm.

Addicted4 · Sep 9, 2016

Curious on how the coil buckets are lined up on the frame to make them straight and true, are you guys just lining them up with the engine cross member? Getting ready to do the swap and that's the one thing I haven't found in all the threads I've read is the coil bucket placement thanks

markfuga · Sep 10, 2016

Best way to line up the buckets is to have the radius arm brackets mounted to the frame first and then slide the front axle under the truck (attached to the radius arm brackets). Next set the frame/body to an approximate "ride height" then line up the spring buckets directly over the spring perches on the axle so the springs are as straight up and down as you can get them. The OBS frame is narrower in the front so the springs will be tilted in about an inch on each side. It's best to align them as straight up and down as possible.

All the threads I've read state to mount the radius arms brackets by "bumping" them up to the front cab mount brackets on the frame. That's a great reference point, but use a tape measure before drilling holes to measure between the spring eye bolt centers front (radius arm) to rear on each side to be sure the measurements are the same. This will parallel the rear and front axles. Just bumping the brackets is a SWAG and won't guarantee the axles are perfectly aligned. Measure between the front spring mount hole of the rear springs to the hole in the radius arms.

sdh1994 · Sep 13, 2016

Does anyone know if the abs wires need hooked up when doing this swap? Just wondering cause if not couldn't non abs wheel hubs be used if needing to replace old ones?

markfuga · Sep 13, 2016

The ABS wires are not needed, so yes, non-ABS hubs will work fine. The OBS trucks have rear ABS only. It's also best to swap the sensor in the rear axle, using the OBS sensor in the SD axle.