BUILD UP IDLER ON DOZER

Date 06-01-2008 17:45

Hello J-ROD, you will likely need to determine what type of over-lay rod is needed to make this repair first. I haven't done this sort of thing in many years so I can't help you with any rod suggestions, however there is one of the fellows on the forum here that works for Stoody and by using the search function you might be able to figure out his screen name and be able to contact him for suggestions. If you have a welding supplier in your area that you feel is competent to help you with selecting the proper build-up rod I would try to get with them so that you can get the specifics of how to apply a particular weld build-up electrode. If there is lot of build-up to be done you will first want to apply "soft" weld metal to cushion the final layer of the hard-rod, most folks will use E-7018, E7014, or a similar type of rod. Preheat is definitely a good idea before starting the repair, I believe around 300F to 400F would suffice. If you do plan on doing the welding with the idler still on the machine you will want to be sure to ground directly to the idler itself and not anywhere else on the machine, this will prevent damage to the bearings in the part. It's really best if the repair can be made while the idler is dissassembled so that you can avoid over-heating the bearing races, yet I have seen many done while still on a machine. Hope this has been of some help. Best regards, aevald

By RioCampo (***)

Date 06-01-2008 19:21

J-Rod,

I have done this a few times myself. It will be time consuming. If you can get the idler off the dozer and on to you truck it will be much easier. then you can just turn the idler around as you need to.
I generally use 7018 to build up then hard surface with Ranite M Rods. I have never preheated when I do it, but depending on where you are climate wise, it might not be a bad idea. It will have plenty of retained hit once you get around it. The idler itself, or at least the ones I have welded on aren't anything but soft steel they are nothing special. I have welded on CAT and Deere they are basically the same.
Make sure you cover the polish rod before welding. Polish rod goes into the roller frame and aligns the idler with tension spring.

By JHarlos (**)

Date 06-02-2008 02:32

THANKS THAT IS WHAT I WAS THINKING TOO. I WAS HONEST WITH THE GUY, AND TOLD HIM THAT I HAVE NEVER DONT THAT AND I DIDNT KNOW WHAT KIND OF MATERIAL THE WHEEL IS MADE OF SO I DIDNT KNOW WHAT WOULD HAPPEN. ALSO TOLD HIM IT WOULDNT BE CHEAP WITH THE AMOUNT OF WELD TIME IT WOULD TAKE, BEFORE I STARTED TO CHECK ON A NEW ONE.

By JHarlos (**)

Date 06-02-2008 23:00

Well, went out and tried to build up the idler today and BAD stuff happened. After cleaning and I did preheat, couldnt find my temp sticks for low temp heat so dont know just how hot I had it. However I know it wasnt glowing. Started off with a low hydrogen 7018 and after one complete pass I heard so lite pinging and noticed that the idler was cracking about every 6 inches. Any ideas what that was from?

By aevald

Date 06-02-2008 23:26

Hello J-rod, sounds like you weren't the first one to do something with this idler. It is likely that previous welding has come into play here and you are dealing with the hard deposits from a previous repair. Others may have some suggestions for you, but I believe I would entertain the possibility of locating another idler in lieu of spending countless hours removing the hard stuff so that you can get to virgin metal to try and make the repair. My $.02 Best regards, Allan

By RioCampo (***)

Date 06-03-2008 02:13

Sounds to me like it has been done before. You could fix it but jeez, I think another idler might be cheaper.

By PhilThomas (**)

Date 06-01-2008 19:56

Hi J-Rod,

I would suggest using Stoody Build Up LH to get back within two layers of the proper dimension and then finish with Stoody 1105 (http://www.thermadyne.com/IM_Uploads/Literature/lit_19_Cse002.pdf). The same alloy is available as gas shielded wire (105-G) and sub-arc (Stoody 105) if you prefer.

Hope that helps.

By theweldor (*)

Date 06-02-2008 02:49

The ideal way to do that would be to turn it slowly and set a mig machine up on it. If you can get it off the machine and build a little jig to power roll it. I have done quite a few of these. Never did one by hand way to expensive that way. Automateing the process makes it worth while though. They are not hardened. I always used 70-S6 wire.