View Full Version : Modifying axel tubes


Solar Aviator
03/22/06, 06:40 PM
Anyone have experience removing and replacing axel tubes? specifically, how hard is it cut out the rosette welds and remove the tubes. How tight is the press fit to drive the new tubes in? Do the tubes have to be turned to size?

bmc69
03/22/06, 06:50 PM
Sure do. We do it. It's a beach. We blow the plug welds out with a torch and then heat the dif housing a bit and drive the tube out with a sledge against the knuckle. And that is the EASY part. The part of the axle tube that fits in the dif is machined to the correct diameter on its OD and machined for the axle seal lands on its ID.

Solar Aviator
03/22/06, 08:24 PM
What do you use to drive the tubes back in? What kind of press fit dimensions do you use? I've got the tools to do the job. Just need some details. Thanks...

Cavalry
03/22/06, 08:52 PM
What do you use to drive the tubes back in? What kind of press fit dimensions do you use? I've got the tools to do the job. Just need some details. Thanks...

why drive them when you can shrink them back in? rule of thumb I have always been told was .002 per inch

dont know what you are doing here...but pulling knuckles off and changins things around there is easier IMO. Less casting to heat, less to machine

Pa PITT
03/22/06, 09:11 PM
Hey B M C 69
I Hate To Rob This Thread But Let Me Ask A Guestion
I Have A Dane 44 Front Housing That Was Broken In A Wreck ...
I Keep Looking At It Thinking I Could Fix It ....cowboy Style...
But It Is Broken At The 3rd Member Side Where The Tube Goes Into It
You Can See About 3 Cracks That Are Spread Maybe 1/8 Inch At Most ...
Still It Looks To Me Like Take Every Thing Out Of It And Sight Thru And Put A Jack Under It If It's Out ....measure Everywhere You Can Find ...then Weld Those Cracks Up ....i'm Like The Other Guy ..i've Got Some Good Tools .press ..lathe ..or Should I Scrape It ..been Looking At It For Several Years.....front End Shop In Ft Worth Want Several Hundred Bucks To Fix It ...hell I Could Buy Another Cheaper...

Cavalry
03/22/06, 09:21 PM
Hey B M C 69
I Hate To Rob This Thread But Let Me Ask A Guestion
I Have A Dane 44 Front Housing That Was Broken In A Wreck ...
I Keep Looking At It Thinking I Could Fix It ....cowboy Style...
But It Is Broken At The 3rd Member Side Where The Tube Goes Into It
You Can See About 3 Cracks That Are Spread Maybe 1/8 Inch At Most ...
Still It Looks To Me Like Take Every Thing Out Of It And Sight Thru And Put A Jack Under It If It's Out ....measure Everywhere You Can Find ...then Weld Those Cracks Up ....i'm Like The Other Guy ..i've Got Some Good Tools .press ..lathe ..or Should I Scrape It ..been Looking At It For Several Years.....front End Shop In Ft Worth Want Several Hundred Bucks To Fix It ...hell I Could Buy Another Cheaper...


d44's are pretty cheap...why dick arond with it when you can get one for a couple hundred? not worth the welding rod and time to fix it IMO. It wil never be "perfect" again

bmc69
03/23/06, 07:44 AM
I wouldn't mess with a busted housing on a D44 myself.

The tube is actually a very loose fit in the housing, not a hard press fit. The machined diameter of the tube is actually slightly under the ID ofthe axle housing or 'size on size' for a loose press fit. They always seem tighter than that coming apart but its not how they measure out..

FWIW...We have stopped narrowing D44s and D60s the 'hard' way. Instead we simply cut a section (or sections if it's rear axle) out of the tube (approx 5" to narrow an HPD44 to use EB inner axles), and butt-weld the ends back together while jigged. We then clamshell splice the entire tube length with 1/4" wall DOM that has the ID matching the OD of the stock tube. No machining and no fussing with pulling the tube out of the housng or the knuckle casting off the tube.

We also truss and box the D44 housings full width..but don't bother with that for the D60 rears. We have an HPD44 in the shop being built like that right now and it just 'started'..its all cleaned and stripped but not cut yet.. I'll take pics of the process and post them for everybody.

Solar Aviator
03/23/06, 08:22 AM
It's great to have this resource available. Life is too short to learn everything by experience.

Thanks Again, Dave...

Solar Aviator
03/23/06, 08:30 AM
One more question. Do you preheat or normalize your axel welds?

bmc69
03/23/06, 08:49 AM
No preheating. The butt welding of the tubes is a three-pass process (V-groove, single-side, post-ground flush to surface). The installation of the clamshelled tube splice is also a multi-pass process. We are very carefull about the sequence to equalize distortion and 'pull' but do not post-relieve the weld zones. Multipass welds tend to relieve themselves in the materials we are dealing with in an axle housing (cast steel dif and knuckes and 1020 or similar tubes)

The trickier part is adding the 'truss box' without distorting the axle over its full width..since all the material and welding is on one side only. We prebend/prestress the entire housing in the opposite direction with a big press frame especially built just for that kind of thing.

Here is a pic of a finished one..but note that this one was modified by pulling the long-side tube, not by using the splice-tube method. Some folks will also note th ground clearance penalty..but thats a tradeoff for having a D44 that holds up with 39.5" tires.. ;D

http://www.supermotors.org/getfile/186701/fullsize/DSC00760.JPG

Cavalry
03/23/06, 02:21 PM
The trickier part is adding the 'truss box' without distorting the axle over its full width..since all the material and welding is on one side only. We prebend/prestress the entire housing in the opposite direction with a big press frame especially built just for that kind of thing.


how much are you preloading? if you go too much or too little can you bend the axle housing back straight?

bmc69
03/23/06, 02:30 PM
With the ends blocked a the knuckle mounts and hte ram on the housing, we press aproximately 0.200" of distortion in to the thing, measured at the ram location. Then we weld up the truss strap and box it both sides. When we let it go and the assembly returns to its correct alignment. This was all worked out by trial and error with a trashed D44 housings..we simply went ahead and trussed one without any restraints on it to find out how much it bent and then used that to figure out the preload amount.

No, you could not post-bend that thing if it came out wrong.

We fab large, and often complex, and stainless structures to close tolerances for ship applications..'chasing' weld distortion is our business. ;)

XT700
03/23/06, 07:03 PM
bmc69,
Do you build these axles just for yourselves or do you sell them to others? Might be interested in one of those HP D44 housings, especially since you are on the East coast. Would be able to pick up rather than have shipped. ;D

Pa PITT
03/23/06, 09:20 PM
Ya That What I Tought Why If You Can Get One For 200.00

And I Had Not Had The Thought ..it'll Never Be Perfect Again ...
But Then The 200.00 One Is Probley Not Perfect Either With Todays Equipment...
Pa Pitt..

bmc69
03/24/06, 07:03 AM
bmc69,
Do you build these axles just for yourselves or do you sell them to others? Might be interested in one of those HP D44 housings, especially since you are on the East coast. Would be able to pick up rather than have shipped. ;D

With 8 EBs , a couple Scouts and a couple full-size Broncos..plus the 4x4 race trucks (Team Trick Trucks)..we're kinda 'blocked up' in the shop, if you know what I mean. %) ..but I'll make a tech article out of the one (HP D44 out of 78 F-150) we've got in the shop now that is being narowed to go in a '68..with an ARB and 4.88 gears, Yukons with Superjoints, etc.