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It could be welded, but not with a MIG. The proper cleaning, prepping the crack and temperature controlling of the part is necessary and a TIG would be used to actually weld it.
In other words, it's easier to just replace it.
Why would a MIG be particularly unsuitable for welding this? I am not planning on welding and using it anymore, just curious since I do just enough welding to be dangerous haha. Seems like it is a pretty solid steel piece and a small weld (should only take a couple seconds) so I woudln't think I would be heat cycling the metal enough to cause any structural damage to it.
Why would a MIG be particularly unsuitable for welding this? I am not planning on welding and using it anymore, just curious since I do just enough welding to be dangerous haha. Seems like it is a pretty solid steel piece and a small weld (should only take a couple seconds) so I woudln't think I would be heat cycling the metal enough to cause any structural damage to it.
It can be done, but is hard to do without further cracking and typically isn't as strong as a rod or TIG welded joint that was done with pre-heating. You have to do very short beads and then immediately peen or hammer the weld with a pointy hammer to relieve the stress in the weld bead so it doesn't crack.
It would probably just crack open again if you just ground that crack into a V and welded across it like you'd do for mild steel.
It can be done, but is hard to do without further cracking and typically isn't as strong as a rod or TIG welded joint that was done with pre-heating. You have to do very short beads and then immediately peen or hammer the weld with a pointy hammer to relieve the stress in the weld bead so it doesn't crack.
It would probably just crack open again if you just ground that crack into a V and welded across it like you'd do for mild steel.
Interesting. Thanks for the info and link! I actually didn't realize that that part was made of cast iron. Thought it was just steel. Shows my metallurgy knowledge... haha
So something kinda interesting I found when taking the trailing arms apart. The drivers side (the side that failed by the way) has been replaced before. It's fairly obvious as the bearing grease was bright red (clearly some of the newer synthetic grease, not the old brown/grey bearing grease that I found in the passenger side bearing housing). Also, as you can see in the picture below, the drivers side spindle is way newer and clearly hasn't been subjected to as much road grime/salt as the passenger side.
Trailing arm rebuild is coming along slowly but surely, I'm updating my build thread as I go if anyone is following this and considering whether to rebuild their own or not.
To some people it may not matter. But I remove the rivets that held the rotor on the older spindle. I doubt they would fall out...but I take no chances in a one of them falling out and doing something to the parking brakes.
Also...due to the next step you should take when you get this completed. I would clean the surface REALLY WELL where the rotor is against the spindle. You want that area really clean so when and IF you choose to index your rotors...that surface is clean and no debris of any type in the way of that process.
To some people it may not matter. But I remove the rivets that held the rotor on the older spindle. I doubt they would fall out...but I take no chances in a one of them falling out and doing something to the parking brakes.
Also...due to the next step you should take when you get this completed. I would clean the surface REALLY WELL where the rotor is against the spindle. You want that area really clean so when and IF you choose to index your rotors...that surface is clean and no debris of any type in the way of that process.
DUB
Thanks, I'll do that.
And I plan to clean the spindle before setting rotor runout. I haven't done any reading on that yet, but I'm assuming I measure the runout with a dial indicator and then adjust it with shims between the rotor and spindle?
Where are the splines on the new axle? Look on the face to see if there is a logo of an "S" with an arrow through it- USA made Spencer Forge. DUB is correct- deburr the axle flange and boths sides of the rotor hat holes. I bolt them on so I fit them well before assembly.
I sent my trailing arms to Bairs at about the same time you started this. They are out for powdercoating right now, but I should have them back soon. I'm pleased to see you are ahead of me!
FWIW, both of my caliper mounts needed to be replaced. One was cracked, one was bent. Each was $65-.
Gary, is there a writeup for what you do to the rotors and hubs to use screws? Bairs will put in new rivets, but they do not thread for hex head screws as you have (I asked that specifically). Should I just ask them to balance the rotor without rivets, and tap for flathead screws when I get everything back? That might be harder with the parking brake installed.
Last edited by Bikespace; Jul 16, 2018 at 04:53 PM.
'Bikespace'
I would tell them to NOT use rivets. They are not needed....due to the lug nuts will hold the rotor in place correctly when torqued properly.
Now if you want install screws...that is your choice.
AS for them taking the time to index your rotors...they do not do that also. So i would not ahve them turn your rotors either UNLESS they just clean them up.
Where are the splines on the new axle? Look on the face to see if there is a logo of an "S" with an arrow through it- USA made Spencer Forge. DUB is correct- deburr the axle flange and boths sides of the rotor hat holes. I bolt them on so I fit them well before assembly.
Originally Posted by DUB
I noticed the same thing that there are no visible splines on the new stub axle.
Yes...some shim stock will go between the rotor and spindle when getting the rotor run-out correct.
DUB
Ha, that's funny, they are wrapped in duct tape which happens to be the same color as the spindle so you can barely see it. Splines are in good shape.
I sent my trailing arms to Bairs at about the same time you started this. They are out for powdercoating right now, but I should have them back soon. I'm pleased to see you are ahead of me!
FWIW, both of my caliper mounts needed to be replaced. One was cracked, one was bent. Each was $65-.
Gary, is there a writeup for what you do to the rotors and hubs to use screws? Bairs will put in new rivets, but they do not thread for hex head screws as you have (I asked that specifically). Should I just ask them to balance the rotor without rivets, and tap for flathead screws when I get everything back? That might be harder with the parking brake installed.
Nice! I painted mine over the weekend. Plan is to install control arm bushings tonight (only have an hour or so of free time) and then hopefully bearing end play tomorrow or Friday (should have a few hours free). If all goes well, I maybe reinstalling my trailing arms this weekend!
Yeah i had to order one new caliper bracket, thankfully the other one was good!
I hope you are paying attention to the bearing setup. I am doing a set of arms now and found one support, 1977, was not machined correctly. It is still good BUT if someone tried to setup the bearings using a standard shim kit no way it would be dialed in. I had to machine the spacer and shim to dial in the bearings to -0- lateral play (0015" endplay).
I hope you are paying attention to the bearing setup. I am doing a set of arms now and found one support, 1977, was not machined correctly. It is still good BUT if someone tried to setup the bearings using a standard shim kit no way it would be dialed in. I had to machine the spacer and shim to dial in the bearings to -0- lateral play (0015" endplay).
thanks for the heads up! I'm just about to head to the garage to get to work on this. The week was busy, so today is control arm bushings and bearing setup and hopefully final assembly.
Both trailing arms are done! Thanks for all the help guys. Got both sides end play down to .001". Both rotors are between .003" and .004" runout. Started trying to reinstall them on the car, but decided I need another pair of arms. I was worn out last night and tried to hold the arm up and put the bolt through, and realized it wasn't gonna happen. So next time the wife is free I'm gonna borrow her for a few.
This job was easier than I expected, but also way more time consuming. It definitely makes sense to send your trailing arms to a vendor to have them rebuilt considering the time involved. Ultimately I saved money rebuilding them myself, and I have the peace of mind knowing I have really well setup end play. After parts, special tools, chemicals (bearing grease, parts cleaner, etc...) and materials (bolts and steel plate to make a couple tools) It cost me about $500 to rebuild these. But it was also at least 20 hours of labor for me (I worked slow and triple checked my work).
Good job but you didn't bend the anchor lock tabs over onto the bolt head. I finished up the set I was building on Sat as well.- 0015" endplay with no lateral play, 0005"-001 rotor runout without turning a chip.
Be sure to use antisieze on the front bolt and torque them with the weight of the car on them.
Good job but you didn't bend the anchor lock tabs over onto the bolt head. I finished up the set I was building on Sat as well.- 0015" endplay with no lateral play, 0005"-001 rotor runout without turning a chip.
Be sure to use antisieze on the front bolt and torque them with the weight of the car on them.
Thanks for noticing that, I'll get those tonight!
Wow, that is really good rotor runout. I wasn't super picky once I got it down to about .003.
This is probably a dumb question, but do I need to get an alignment after reinstalling the trailing arms? Or if I put my shims back in the correct order (I marked them when I removed them) am I good to go?
