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Class 8 driveline build/ assembling

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
I've been getting a lot of 1710 and 1810 driveline jobs. I'm wanting to invest in some assembly fixturing.

I support the tube in V-blocks, heat the tube ends, slip the ends in with an alignment fixture on a flat table. Then I put them between centers in a lathe and tweak until the tube ends are with 5 thou. It's the tweaking the ends that's the cocksucker. Common to be out .050". Class 8 stuff doesn't move easily.

I'd like to be able to assemble the ends to the tubing in phase in the lathe, as straight as possible and tweak them in while the ends are cooling.

Anyone else made tooling for bigger driveline work?

This isn't my primary gig, but the closest decent driveline shop is a couple hours away with a couple weeks backlog common. Lots of logging, aggregate and offroad guys around me to support driveline repair.
 
Maybe make up a D1 backing plate fixture for one of your lathes that holds that stub end in alignment, and another for the tailstock with a split bore that clamps on the T/S barrel to hold the other stub end in alignment? That should allow you to just push them in while warm and leave them until they cool.
 
Maybe make up a D1 backing plate fixture for one of your lathes that holds that stub end in alignment, and another for the tailstock with a split bore that clamps on the T/S barrel to hold the other stub end in alignment? That should allow you to just push them in while warm and leave them until they cool.

Once the tube gets below a couple hundred degrees you can't really move it. If I fuck up I have to let the whole mess cool down and hit the tube hard and fast with my big rosebud to create the temp differential necessary to shift the joint.

For that reason I want to be able to align, assemble the ends in the lathe and then have the capability to rotate the shaft during that transition period to tap the ends into alignment. As soon as the tubing grips the ends enough they cannot rotate I need to be turning the tube with an indicator on it. There's probably a 20 second window where alignment is a piece of cake. Seconds later it's a whole lot of suck.
 
I've done lots of driveshafts but never late class 8 stuff. I wonder if an induction heating coil would work?
I assume you've seen the job specific machines made for driveshafts, like Remco?
 
I've done lots of driveshafts but never late class 8 stuff. I wonder if an induction heating coil would work?
I assume you've seen the job specific machines made for driveshafts, like Remco?

I've seen some commercially made machines, but they were for pickup sized stuff, pretty light duty.

I've used all four driveline shops in my region. One of my gearhead friends ran one of the sketchier ones for a decade. Of those only one is also a full machine shop and does the big stuff. They built their own driveshaft assembly machines. They gave me a tour when I asked years ago and their biggest machine is made from massive welded box sections of 1"+ thick plate, their end tooling was all straight shank.

My goal is to handle vehicle stuff through class 8 truck and ag drivelines using the lathes I have as the assembly machines. I need to make it more efficient though. I've had some 8 hour drivelines that kicked my butt. I charged for it and I was still competitive. I guess bottom line is I want to enjoy doing drivelines regularly. I think if I actively searched for the work I would be buried in it and really hate doing it in a short time if I don't step up my game.
 
I've seen some commercially made machines, but they were for pickup sized stuff, pretty light duty.

I've used all four driveline shops in my region. One of my gearhead friends ran one of the sketchier ones for a decade. Of those only one is also a full machine shop and does the big stuff. They built their own driveshaft assembly machines. They gave me a tour when I asked years ago and their biggest machine is made from massive welded box sections of 1"+ thick plate, their end tooling was all straight shank.

My goal is to handle vehicle stuff through class 8 truck and ag drivelines using the lathes I have as the assembly machines. I need to make it more efficient though. I've had some 8 hour drivelines that kicked my butt. I charged for it and I was still competitive. I guess bottom line is I want to enjoy doing drivelines regularly. I think if I actively searched for the work I would be buried in it and really hate doing it in a short time if I don't step up my game.

Are you not pre-machining the inside of the tube at the ends ?
Why not a less press fit done cold ?

The yokes get welded afterwards anyways.
 
Are you not pre-machining the inside of the tube at the ends ?
Why not a less press fit done cold ?

The yokes get welded afterwards anyways.

Two problems with that route-

Tubing is only mostly round, but it becomes very round when you stretch it around the yoke stub, then you can accurately indicate. If I bore thinwall tubing I have to also cut the OD so it's concetric. Kind of a can of worms. I do it for weird shit like a crossbread Dana/Toyota driveline sometimes, but usually avoid it.

Secondly I have seen them fail when the tube isn't a tight enough fit, especially in dumptrucks. I do a fair number of 1710 shafts under semis that have been converted from road trucks to dumptrucks. Dump should have 1810, but it costs a lot to convert everything. Job security for me anyway.

I don't think it takes any more work to assemble them with a tight press VS boring if I have my shit together.
 
I've got a 10" hole turret lathe that would make a dandy assembly station.

I bought a J&L 8A-5 with a barfeeder and rotating steady for exactly that. I hardly used it, but it was a nifty machine. Thing was like a Cadillac. Sold it a few years ago to a guy needing to part off irrigation tubing for something.

I most definitely have enough manual stuff. I need to justify what I have.
 
How does it fail? Tube fail, or weld break?

This one broke at the shaft the carrier bearing is mounted on. It had been done by a driveline shop and they turned down the shaft to be a light press in the tube when they did it. You can see how the tube ID was fretting on the yoke before it failed. It peeled the weld off the yoke, the weld is a bit cold.
 

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Two problems with that route-

Tubing is only mostly round, but it becomes very round when you stretch it around the yoke stub, then you can accurately indicate. If I bore thinwall tubing I have to also cut the OD so it's concetric. Kind of a can of worms. I do it for weird shit like a crossbread Dana/Toyota driveline sometimes, but usually avoid it.

Secondly I have seen them fail when the tube isn't a tight enough fit, especially in dumptrucks. I do a fair number of 1710 shafts under semis that have been converted from road trucks to dumptrucks. Dump should have 1810, but it costs a lot to convert everything. Job security for me anyway.

I don't think it takes any more work to assemble them with a tight press VS boring if I have my shit together.

Thank you for the feedback from "Them that's doing".

So that explains the other shop's "massively built" press.

I'm wondering about running an expander in the bore, should round things up nicely.
 
This one broke at the shaft the carrier bearing is mounted on. It had been done by a driveline shop and they turned down the shaft to be a light press in the tube when they did it. You can see how the tube ID was fretting on the yoke before it failed. It peeled the weld off the yoke, the weld is a bit cold.

If that is fretting (I can't see it in the pix) then I would think some holes drilled in the tube ahead of pressing time, for some plug welds (afterwards) would keep the tail from wagging.
 
I think a better weld should eliminate the fretting all by itself as long as there's a good tight fit. That example doesn't show much penetration as far as I can see.
 
Two problems with that route-

Tubing is only mostly round, but it becomes very round when you stretch it around the yoke stub, then you can accurately indicate. If I bore thinwall tubing I have to also cut the OD so it's concetric. Kind of a can of worms. I do it for weird shit like a crossbread Dana/Toyota driveline sometimes, but usually avoid it.

Secondly I have seen them fail when the tube isn't a tight enough fit, especially in dumptrucks. I do a fair number of 1710 shafts under semis that have been converted from road trucks to dumptrucks. Dump should have 1810, but it costs a lot to convert everything. Job security for me anyway.

I don't think it takes any more work to assemble them with a tight press VS boring if I have my shit together.

I don't understand why you would need to turn the OD.

Do you think the failure pix you posted was from simple overloading ?
Maybe any weld, any press fit would have failed in that truck.
 
You want the tube centered about the axis of rotation right? on the road, at freeway speeds you will feel the difference between under 5 thou runout and 10 thou+ if it's not balanced. This is exagerated the bigger the tube. 3" .100 tube is not as bad as 4" .200 wall tube. I'm sure you get the idea.

If you take a cut on the ID of the tube it won't result in a uniform wall thickness. That fucks up your ability to indicate the tube where it matters most.

This is how it works in my head anyway. I hillbilly'd a lot of drivelines together before I ever had a machine shop and most of them worked pretty OK. A few years ago a guy brought me one to fix from an old truck he had. It was twisted right off and it was made from the thinnest shittiest tubing, like .040" 3.5". I couldn't believe somebody would do something like that. Then I remembered building a driveline like that for a truck I built and sold many years earlier. It was mine.

I think sometimes machinist thought process can overthink the hell out of stuff. I'm sure there's millions of half assed drivelines out there doing great. I know I made some of them.


I agree the weld was cold on that broken tube.
 
They are not the heaviest the heavy ones are Mack drivelines with heavy wall tubes and earthmoving shafts.
when i was a apprentice ( then tradesperson ) the shop did these and many others as well as other work.
We assembled them by hitting the yoke in with a large hammer ( hefty pounder ) and drift typically the smaller shafts has about 0.002 interference the bigger ones you can go a little more but not too much.
Tube is sometimes not round but is pretty good, all you do for that is average it and add some interference fit.
To align we just sat it up in a vice and knocked a end to align with the other...we used straight edges sitting on the cap ends or caps ( machined surfaces ) and sighted along the edges...nothing too fancy. The vice we had did not crush the tube so be careful what vice you use we grabbed it on the throat of the vice not by the jaws.
Some shafts had missalignment on purpose some 2 piece cv joint ones on cars about 15 degrees out.
generally most if not the majority align the yokes.
We welded the larger shafts in a lathe and knocked them straight before welding. for welding it was tacked first then welded in one go with a mig.

If it had a small amount of runout we shrink one side of the tube by spotting it with a torch then quenching it ...but be warned doing this on excessive runout if not advised and it is better to break the weld and start again.

Balancing was done in a schenk balancer ...some shafts come out fine without the need of added weight but that maybe 1 in 10 most require balancing.
Runout being low is important for balancing and also where you add the weight or take it off for small amounts.


Never did we have the need to shrink fit the tube yokes i cannot see why you need to do this step or have so much interference to require it.

Most of the parts are made by Hardy spicer ...well the good ones are
 








 
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