98 Carryall 6 Transaxle...lots of questions.

[sheit98carryall]

Two other friends and I are working on a Senior Design Project for our school (we are all in our final year getting a BS in mechanical engineering). We are trying to adapt a hydraulic regenerative braking system to a golf cart we were given by the school...problem is we can't begin until we fix the cart.

We have a '98 Carryall 6 with the 12hp Kawasaki gas engine. When we were given the cart it had a note pinned to the steering wheel saying "Do not drive, transmission locks up". This is all the background we have on this vehicle. I have since managed to get the engine running smooth, but upon putting the belt linking the engine to the trans-axle (or whatever these are called) we noticed some problems.

To begin with the trans-axle casing had most of its bolts halfway backed out (I assume they were attempting to fix it). When the trans is put in forward the wheels do spin and accelerate with the throttle, yet when putting them in reverse it will only grind the gears...it also will not go into neutral. Basically its either in forward or grinding the gears, those are the only two options we have been able to find.

How hard is it to rebuild these trans-axles? Is it possible it is simply out of adjustment? The case appeared to be dry...what type/weight/volume oil do they require?

-Any help is appreciated