this is an easy way to remove the main clutch slipping issue with thunderbird yarders, new shaft not needed just a new hub and a new clutch rim fitted, and a new 26x5 bfg clutch, also fitting 26 x 7 bfg to the skyline, the original hydrauics used for actuation etc
What model of Thunderbird are you making this conversion on?
have converted 3 tmy70,s, no clutch slip now,posible to do any tmy50-70 or tty70 etc, yarder owners raving about it.
I like it.. Good Job.. I've been grapple logging with a 255 for the last few years (only one I know off), been after the owner to convert to BFG and get rid of those old air on air off clutches for some time now.
photos of a 26x7 on tmy70 skyline and 26 x 5 main
Really interested in this. Our yarder is lookin at some down time and we have been fighting both of those clutches on our tmy 50. Any part numbers or specs and details you could share would be awesome.
Any more photos of the parts used & process?
Yarder Repairer hasn't been on here since 11/2015, and hasn't made any posts since he made this thread, 7/2015
WE have converted a few yarders now, the conversion is very easy, and doesn't need any shaft mods at all, just remove the gear and rerim, and a new hub made. we have new clutches and a conversion kit available. we moved the cab out to end of chassis on the last one this was easy and no hoses needed lengthening and allowed a lot more room, we also fitted a 124 seat and twin joystick controls into the original cab with push button trans shifter on the joystick, this set up was for a yarder running a grapple carriage so more control, I have found a lot of the main gears cracked especially the yarders running carraiges so have been re rimming the original gear.
Can you email me a parts list & cost for the conversion to [email protected] Thank you
When welding to the gears, is there a particular rod/wire type that you use?
we use low hydrogen wire and peen weld after, also pre heat and post heat. There is full weldng instructions in the conversion kit
Hi team, Bit of a long shot but have any of you come across this issue with the welds breaking before?...
On a TSY 50 used for grapple yarding have had those crack over the years just welded them up and seemed to be holding up. edit Caught the cracks before they looked like that.
Thanks for the reply! Did you weld up in place?
I think on the main clutch they did, but I know on our haulback clutch we pulled it wasn't to bad to pull.
Just made it on here and came across this. Does anyone know where I could get more information? I am located in Oregon and have not come across a 70 that has been converted yet.
You won't find any in the States here that have been converted unless you look at the Active 70. I believe some of those have the BFG clutch conversion.
Thanks Hallback, this must be to add more potential to the 70s for a grapple carriage? Seems like the Boman has to be within kissing distance of the tube to get it up snug at all! They got better once they went back to pneumatic and the 6170 improved it even more with the larger clutch. But the mid to late 80s models with the air to hydraulic valves and the hydraulic cylinder inside the clutch can be a pain! Especially if your chaser likes to keep all his worldly possessions in the Dog Box!
On facebook search for 'Hauler Engineering Ltd' Wakefield, NZ. (in the url bar 'Hallengineeringltd' should show.) They do a bit with the BFG clutches. They don't post too much, so not too far down for a post on the May 29, 2022 , which is a rebuilt TMY 70 with 1 year of work, that has the BFG clutch etc. (also things like a band brake for 071, replacement 124 cab, lagged/ grooved 071 main drum etc)
Thats a great looking machine! I see the cab and dog box was set back to make room for the clutches. I also like the looks of that cab. Without getting too far off topic, does the 124 cab still accommodate the steering wheel for road travel? There are similar cab conversions I have seen locally but only on the TTY that can tilt or be removed. We have an old railroad trestle locally that I am always worried is going to settle and give me and the 70 a haircut trying to get under!
If you're running a Boman on a 70, hopefully it's a Mark 5 or 8900. The 7900 is way too large. I didn't know anybody even ran chasers anymore?
Tandem carriage on TMY 70
I had my hands on two of the tandem carriages today. There are a nice setup, I just wonder if they're robust enough for the average yarder operator and crew but time will tell.