RC10Talk - The Net's Largest Vintage R/C Community

Well I finally got one at a reasonable price I think after the Yokomo 834b this was the car I dreamt off most as a kid , I've always loved cage cars but I never thought I'd ever find a Bulldog at a reasonable price .
This one is not fully original , previous owner put a second steering servo on for the rear steering and there are the mandatory screws missing , minor bodges and worn parts .
To anybody who's familiar with the Bulldog the most intriguing thing are the air shocks and they were the first thing I looked at , they looked good externally but were very stiff , now these units are sealed but very simple , the only adjustment is by a grub screw at one end that controls air escaping to give the damping , so I backed off the grub screw and fed 10w damper oil into the hole to re-lubricate the piston O ring inside , it worked a treat ! but man oh man when I drained out the excess oil it came out black ! I repeated the action several times till the drained oil was just grey but they work really well now , better than I expected
Next I looked at the diffs deary me , the front diff felt smooth but was slipping , mid diff had no little thrust bearing at all and the rear felt like gravel
In short all 3 diffs had balls were worn badly , flat spotted and the washers were grooved as bad as I've ever seen .
I'm now waiting on balls from eBay before rebuilding .
Otherwise the cage is intact and the rest of the chassis has been well cleaned up by the last owner , it's had Hotshot wheel axles and wheels fitted and I'm not sure about that , its practical but is probably why the price was right , I may keep the twin servo steering or at least try it .
Pictures soon.

My diff balls arrived today so I had an afternoon of rebuilding 3 diffs . Below is a picture off a PDF from DirtBurners of the instructions .

The small counter thrust bearing setup is just weird ! it actually uses the underside of the screw head as one thrust washer ! and the diff side has a conical area that is the other thrust washer ! There's not much extra depth in the diff outdrive cup but there was at least enough to put a proper thrust washer under the screw head .



I now have three smooth diffs , I also fitted a spring to the mid diff that aids adjustment .

I also borrowed an idea from Bormak about belt tensioning detailed in his Bulldog Mod thread https://www.rc10talk.com/viewtopic.php?f=33&t=17396&hilit=bulldog+mod
As suggested in the thread I fitted a tensioner to the rear drive belt but I fitted it on the return side of the belt rather than the tensioned side .
I put a slot in where the line is marked internally .

The adjuster is just behind the motor .

I left the front belt for now as its under way less stress . With these bits done it was time to rebuild , the last things to address was the steering , the threads in the bell cranks are all slightly loose on the threads ! plus the rear was assembled wrong ! this looked like the easiest refit I'd ever done but in detail it still needs work , I can just use longer screws and nuts to rectify the stripped threads in the steering .

Still can't believe I have one

Next on the list was the steering , the previous owner had fitted a second servo for rear steering and replaced all the steering linkages , the twin servos needed a Y harness and a direction reverse cable to get working but it's quite satisfying , all the linkages would look great on the shelf but were so poorly assembled that they fell apart by looking at them , took a trip to a hardware store for nuts and screws to fix , he'd also got as much rear steering as front , I refitted the linkages and servo horn hole position to give 1/3 steering roughly to the rear , both servos had the horn fitted way off centre as well

I found a set of 3d printable bulldog style wheels in 1.9 for hotshot tires on Cults3d , they looked really nice until I put them in my slicer program and there was very little material between the holes so I designed a set myself , they also have a deeper offset than standard hotshot wheels .


Kind of hard to see but the rear wheels are the new ones .

These are printed in Polycarbonate
I've finally been able to drive a bulldog took a lit of trimming to set it to go in a nice straight line , reduced end travel and a fair bit of expo to make it really drivable , in doing the setup I coasted into the kerb bumper first , there are already white stress marks and it's part of the cage and virtually unobtainable so I'm going to do what I did with the Samurai I'm going to make a Kydex undertray with integrated front and rear bumpers this time .

Really nice work there.

The Bulldog did very well in Australia. Team Pitstop modified and raced them after they stopped using their Taipans and before they changed to the Schumacher Cat.

1300GT wrote: ↑Sun Aug 22, 2021 6:55 pm Really nice work there.

The Bulldog did very well in Australia. Team Pitstop modified and raced them after they stopped using their Taipans and before they changed to the Schumacher Cat.

It's hard to believe how quickly things changed Taipan to CAT with only one car between !

The 2mm Kydex sheet came today so I made a front bumper to preserve the cage , its slightly darker than the cage but I can live with it .

You could take it off and leave it in the sun until it matches.

Or not.

Great idea for the added bumper.

Looks great, Dadio.

I wasn't aware that Kydex came in blue. I've only gotten it in black.

Anyway, I can find no problem with the slight color mismatch -- it looks like a factory piece.

It's not an entirely new idea , I spied additional bumpers in the second picture in the first post or Bormak's thread , https://www.rc10talk.com/viewtopic.php?f=33&t=17396&hilit=bulldog+mod

Very cool buggys I got a couple.. may possible let them go

Awesome Dadio! It looks great. The Bulldog is one of the unique RC buggies I have always wanted like the Coyote.