Marlin Tack aka Martack 80 series

[LandCruiserPhil]

Last time I tried it, a thing of PVC pipe was all it took. And a zip tie to put it back in.

It is an interesting prospect to not need c-clip but how precise the weld has to be? also doesn’t the c clip keep the axle in place in both directions as suppose to one direction, does that matter?

I’m probably missing something, I can only visualize it preventing the axle go into the birf too much which I don’t thing would be an issue but don’t know how it would prevent the axle go into the third or that just won’t happen.

The tack is not on or needed on the birf end. The tack keeps the axle from going into the diff. There is no reason not to do it but several reasons to do it.

 

[Thecriscokid]

Good ol LCP. Always nice to see his mods.

 

[Qball]

Last time I tried it a thing of PVC pipe was all it took. And a zip tie to put it back in.

The tack is not on or needed on the birf end. The tack keeps the axle from going into the diff. There is no reason not to do it but several reasons to do it.

Ok I got the birf part but help me under stand how it prevents it from going into the diff. What would hit/catch the weld and prevent it going into the diff? Does the weld act like the c clip and fit into the groove and hold the axle in the birf?

 

[LandCruiserPhil]

Ok I got the birf part but help me under stand how it prevents it from going into the diff. What would hit/catch the weld and prevent it going into the diff? Does the weld act like the c clip and fit into the groove and hold the axle in the birf?

The birf is held in place and tight against the spindle bushing by the c-clip on the outside of the drive plate and needs nothing else to keep it in place. By tacking the axle on the diff end it keeps the axle in place and out of the diff.

If you blow a birf on the trail removal of the birf becomes more a challenge if you dont have your piece of PVC. Very doable without and not a problem if you are in the know but most that are in the know have already Martack'd there axle.

Martack is a Marlin thing originally to make for easy quick replacement of birfs on mini trucks because small birf were frequently blown.

 

[Qball]

The birf is held in place and tight against the spindle bushing by the c-clip on the outside of the drive plate and needs nothing else to keep it in place. By tacking the axle on the diff end it keeps the axle in place and out of the diff.

If you blow a birf on the trail removal of the birf becomes more a challenge if you dont have your piece of PVC. Very doable without and not a problem if you are in the know but most that are in the know have already Martack'd there axle.

Martack is a Marlin thing originally to make for easy quick replacement of birfs on mini trucks because small birf were frequently blown.

Ah thanks, I finally got that the rack is on the diff side so the tack would prevent the axle going into the diff every time it touches the diff spider gears?

 

[80t0ylc]

@LandCruiserPhil

Seems like a great idea. Does the axle tend to stay in the housing when you pull the birf out? How much hangs out past the inner seal? When you go to re-assemble, is there much difficulty aligning birf with axle splines? Sorry for all the questions, just curious.

 

[LandCruiserPhil]

@LandCruiserPhil

Seems like a great idea. Does the axle tend to stay in the housing when you pull the birf out? How much hangs out past the inner seal? When you go to re-assemble, is there much difficulty aligning birf with axle splines? Sorry for all the questions, just curious.

All legit questions
Most of the time it comes out with the birf. IIRC it hangs out ~2". To reassemble you need to do it as an assembly to get the need leverage to line things up.

 

[Mr Cimarron]

I’m planning on doing this in the next couple days since I have it all blown apart. I’m a real s***ty welder. What kind of settings are you guys using on a mig welder? I’m sure it doesn’t matter and I’m second guessing myself but I don’t want to screw it up.
Last time I was trying to install the C clip the birf rolled off the table and landing on my toe. $300 later and an ER visit I was minus one toe nail. Seems like a positive in my book to do this mod.
I will probably bring it to work and let a more experience welder do it.

 

[Somebodyelse5]

I’m planning on doing this in the next couple days since I have it all blown apart. I’m a real s***ty welder. What kind of settings are you guys using on a mig welder? I’m sure it doesn’t matter and I’m second guessing myself but I don’t want to screw it up.
Last time I was trying to install the C clip the birf rolled off the table and landing on my toe. $300 later and an ER visit I was minus one toe nail. Seems like a positive in my book to do this mod.
I will probably bring it to work and let a more experience welder do it.

If you have that option, I'd go that route.

I ended up NOT doing it. Welding temps are well above the annealing temp for steel and I decided I didn't want to mess with the heat treat and cause local material property discontinuities... sure, it'd probably be fine, but my enginerd side got the btter of me and decided that toyota engineers did what they did for a reason and that I ought to leave well enough alone.

 

[Pin_Head]

It is just a tack weld, so all that matters is that there is fusion so that it sticks.

 

[Mr Cimarron]

Had my coworker make the tacks today. One got a bit far down on us and had to fix with a file. Still have another five minutes or so to clean it up. One thing I'm good at is fixing mistakes.