Has any of our members actually done the Dana 80 Axle swap? (There is one out of a P30 mobile home not too far from me with 5 lug and 47k miles) As well as the P3500HD or similar? Disc brake retrofit?
I have tried to search and read (including the Grigg stick post) but have not come across anyone that has done it or PICTURES, all the pictures that were posted are long gone. So I can't find any good visual reference. I have a home machine shop, welding and fabricating skill, have done engine swaps in the past so I can tackle it after getting some heavy jack stands to be able to work on the truck.
If anyone has successfully updated their front end using the P3500HD spindles, steering and brakes as well as done the Dana 80 upgrade to their their 2 Ton COE (mine is a 1950 Chevy COE) and could share photos and their "recipe" I and I am sure future members would be greatly appreciative.
Marty (P.S. is there anyway to get email notifications from Stove Bolt when an reply is made to your post?)
Gonna follow this thread since I'm kinda in the same boat. I'm interested in doing this swap but I haven't got the axles yet.
As for email notifications, at the top of the thread next to the "Thread Options" button, theres a bookmark button. Click that and you should get emails when a new comment is left.
Grigg is still the man to try to contact about this. I started a project to to the Dana 80 swap on a '50 GMC 2-ton. The rear axle was only going to need the perches cut and rewelded. The front axle was going to need more work. We were thinking we would just swap the Dana spindles onto the existing axle (with machine work and bushings, etc to make the king pins work) because, if my memory serves, the Dana front was going to need to be cut.
I sold that project to Mongo so maybe he can fill you in a on what happened next.
The bottom line is that it is *not* a simple swap. There is a lot of measuring and machining to do to do it right. BUT ... given patience and dogged determination (and more than a few $$$...), it *is* doable and will yield a great set up. Again, though. with the power discs all around and the tall gearing of the Dana 80, this is only worth doing if you are also upgrading the rest of the driveline. On my project, it had a 4-53T Detroit coupled to a 9-speed Road Ranger trans. Your original 216 0r 235/SM420 set up will not have enough power or torque to make this axle swap viable.
Ed Pruss may know more than he lets on about this, too....
John
John
"If there are no dogs in Heaven, then when I die I want to go where they went." Will Rogers
I put P-3500 HD front hubs/spindles on my GMC ‘55.2 front axle. Had new king pin bushings made,($12. ea) ,no other changes. Used ‘60’s tie rod. Spindles need to allow tie rod to reside behind axle. Note: there are at least two types of grease fittings going into king pins, make sure yours are properly lined up(simple). Measure thread pitch carefully, drag link, tie rod, etc., I have found 16 tpi and18 tpi on same truck, hard to tell apart unless measure.
Installed right width D-80 disc brake rear axle, made shims to fit different diameters. Found another set of front spindles/D-80 nearby.
One can use 22.5” wheels with 5/10 bolt pattern(rare), 19.5” wheels with 5/10 bolt pattern (common) or make wheels from scratch or redrill 22.5” wheels with 10 on 8.750” pattern by redrill ink and spacer.
Stories and px in past posts.
Ed
Last edited by EdPruss; Sat Dec 03 2022 03:20 AM.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
I put P-3500 HD front hubs/spindles on my GMC ‘55.2 front axle. Had new king pin bushings made,($12. ea) ,no other changes. Used ‘60’s tie rod. Spindles need to allow tie rod to reside behind axle. Note: there are at least two types of grease fittings going into king pins, make sure yours are properly lined up(simple). Measure thread pitch carefully, drag link, tie rod, etc., I have found 16 tpi and18 tpi on same truck, hard to tell apart unless measure.
Installed right width D-80 disc brake rear axle, made shims to fit different diameters. Found another set of front spindles/D-80 nearby.
One can use 22.5” wheels with 5/10 bolt pattern(rare), 19.5” wheels with 5/10 bolt pattern (common) or make wheels from scratch or redrill 22.5” wheels with 10 on 8.750” pattern by redrill ink and spacer.
Stories and px in past posts.
Ed
Ed, Thank you To be clear, are there different 3500HD axle configurations or were they all steering behind the axle? I mentioned in another post, I *may* have access to a 2000 3500HD front axle assembly, but it appears the steering linkage is in front of the axle. The guy cobbled things together....I can't hardly imagine he reversed the rotors/hubs or even flipped the axle but who knows? It is currently in a 1959 Chevy LCF, the rear in that truck is an 8 lug Dana 70. I want matching wheel lug patterns front and rear.
Will most any Dana 80 rear end out of a '99 to 2002 Chevy 3500 HD work as well with respect to track width under my '50 COE flat bed? Whether it a truck or a motor home?
Thanks again Ed, really appreciate your thoughts and insight. Perhaps you would allow a phone call to set me straight, but sharing the info here will be good for future users seeking the information.
I have this very combination on my bus. Dana 80 rear axle with disc brakes and 4.64 gears out of an early 2000 wrecker and I put 1985 P30 spindles on the front with the same 5 lug bolt pattern with disc brakes. And then added adapters and run Alcoa 22.5" wheels.
Just a little update. I have the Dana 80 rear from the 1994 Chevy 3500HD truck installed. I have the spindles/front disc brakes from the 3500 HD installed. I had to source rear steer arms (which I think is the most difficult part of this swap). Ironically, the original COE tie rod and tie rod ends fit the late model steering arms. I did have to machine the original front axle slightly as the king pin ends were slightly too tall and I mean slightly, with no shim. I am "planning" to use a reverse rotation steering box from a 1978 Dodge W100-200 which mounts to the SIDE of the frame in a cradle. The pitman arm is also sourced from the same vehicle to fit that box. I have not mounted the steering box yet because I want the full weight of the body and bed on the truck first so I can keep the drag link relatively level. I will have to fabricate the drag link. I am going to run 1" steel adapters to adapt to 22.5" Alcoa wheels. Duals would be too wide in back, but I found a super single wheel with a nice offset and like new Michelin tires, so that what I will be running on the back. I had also found a set of 22.5" RV wheels which are narrower than Semi wheels. I felt this was important on the front. I would have rather run the Alcoa RV duals in the back but it looks like they will be too wide. I am waiting on an adapter to test fit before the other 3 are machined.
SO that's where I currently stand. The 9R22.5 tires are slightly taller than the originals and the tires on the super singles are also slightly taller at 40" from stock, but I think the truck will look better than trying to run 19.5" wheels which are 6" shorter than originals. We'll see what shakes out in all of this.
