GM2 Hydraulic Motor Specs

I haven’t been doing a great deal to the site for quite a while now, but have been trying to pin down some methods of keeping older RT45’s alive. 

Despite the lack of new material we still seem to have a respectable number of visitors.

My machine is fitted with two old SAI MT500 drive motors. They weep a bit of oil and show some signs that seals are on the way out. Seals are the only parts for these motors which can be sourced new today. 

Failure of the drive motors seems to be a common enough problem and without replacement parts you can find yourself with a useless machine which has no immediate prospect of repair.

The latest SAI motor of the same family, the GM3A is considerably larger than the MT500 and looks as though it would require at least the relocation of the fuel tank, oil tank and the muffler of the diesel engine in order to fit.

I have had some correspondence with SAI and one of its Australian suppliers. From that it appears that the smaller and lighter GM2 500  motor would actually provide better performance than the original MT500s. Most of the engineering required to fit looks like changes to the hydraulic lines to suit the distributor on the new motor and the machining of the original or fabrication of a new, mount to the brake housing etc.

• The solution looks quite doable but would be expensive as SAI retails the GM2 at over six thousand spondulas a motor.  Given that the existing motors in the older RT45s have seen service since being turned out in the seventies the cost of the replacement could well be justified in terms of projected service life.
• On the other hand there are quite a few purveyors of GM2 copies based in China and Taiwan. I checked with one producer who gave me a price of $580 USD per motor plus freight.
  
• The big issue is whether you can trust Chinese hydraulics?

Any thoughts on this would be appreciated.

Replacement of the newer motors in late model RT45s is complicated by the fact that the assemblies are a combination of a proprietary Austrak casing and third party internals which can be very hard to identify. Most of us will have seen the machine on Ebay which was in that situation and I know of another which could be in the same boat.

With the Wildcat I have often wondered how the parts situation is going for those neat Daiken-Sunstrand transmissions and how they could be replaced if parts are no longer available.

If you have any ideas about keeping our machines functioning, or have come up with mods that keep the old clunkers running, please post it here as we can all benefit from each others knowledge and experience.

Cheers

Austrak Wrecking…parts no longer available …

Check out the Wildcat Subaru engine transplant in the new WILDCAT MODS section

Check out Bryan’s Wildcat with FEL.  Bryan has provided detail pics of the machine as he received it. He’s currently working on restoring it. If you are a Wildcat enthusiast these are a “MUST LOOK AT” set of pics.

• Help provide us with information about AUSTRAKS and WILDCATS/SUPERCATS
• Check out Rodney’s Tilt Blade and steering mods

The best way to stay up to date with what happens with this blog is to register. It’s a simple process and your details will remain private as far as private can be on the internet. It just makes it easier for you to keep up to date with what’s happening.

Also I would like to put together a gallery of people’s machines. If you would like your Austrak or Widlcat to appear just email me a pic at johnarentz@operamail.com and I’ll post it with  your first name and regional location or whatever details you wish.

If you have a story about your efforts with these machines I’m sure we would all love to hear it.

Cheers

Austrak and Wildcat tractors are unique pieces of Aussie agricultural technology. Along with a similar product manufactured in Queensland by Toft  these machines featured a wide range of implements, skid steer and hydraulic drive. Various methods were used to transmit drive to the four wheels including chains, shaft drive and hydraulic wheel motors.

Similarly the power plants were many and varied. Production ran over a considerable time period and the power plants were changed to sui9t availability and upgraded specifications.

Wildcats can be found with Wankel engines, V4 Wisconsin and (later models) with diesels. Austrak used a variety of engines starting with Italian air cooled diesels in the 40hp range and ending up with larger liquid cooled engines such as the Cummins.

My own Austrak is an older model with chain drive and a 3 cyl Lombardini aircooled diesel.

This site has been put together because of the interest people still display in these machines despite the passing of time:

• Hopefully those of us with working machines will use the blog to share information and solve issues relating to them.
• There are a lot of machines out there that are no longer functional and which could be restored or utilised for parts. The blog could also be a way of putting those owners in touch with others who may be interested in purchasing non functioning  machines or parts.
• The site could also be a means of putting would be buyers of  functioning machines in touch with would be sellers of them.
• For those people who are just looking…I hope it becomes interesting as things progress

I have to confess to being a web page…blogging idiot really but I thought it was time this ball got rolling. I’m sure that the site will get better as I learn the tricks or convince the offspring to help me get it right.

In the meantime I have placed a five week ad in the tractor section of the Weekly Times inviting people to participate in this blog and hopefully start building a knowledge base and a support mechanism for owners. I will do the same in the Land asap.

cheers

johnarentz