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

[matt H]

gas carts slow down when you let off the gas , not much freewheel

run a hickey to bober to a do dad

could possibly eliminate the brake pedal

just maybe these things will stop breaking

[ckiguy]

ok type of fluid called for in the book is 80/90 and you will use around a qt and a half or so. no big deal to fill it up. second it will be better to run syn 85/140 in it. or syn 80/90 if thats all you can find. you should have a fill plug on the right side(pass side) about the middle of the case. its a 14mm if i rember correctly. but heres you catch. i would nopt fill it till i find out why some schmock back all the bolts off. i would pull the axle, split the case and inspect bearings and races for overheating/lack of lube. not hard to do if you tear it down, and put it back together with no other hands in it. just take it apart, lay the parts out on a table or board in order, so you can put them back together in reverse. take a ppicture if you can of each step, in case you get side tracked or have to leave it alone for a while. you can always use the pics to help with reassembly! also get in contact with lockman, if i rember he has a service manualo r a way to get you a service manual pages to help with this. he has helped others on her. so ask really nicley! best of all we like pictures! we loike to visabily see the work not just imagine it! plus you might get extra credit for pubilcly investagating your work! soory i wasnt smat enough to go to college o spell, or learn to type correctly!

[jiminpa]

Not sure what your guidelines are on this, but, if your planning on "hydraulic regenerative braking system", not sure exactly what you mean by that, but, I am guessing you are planning on capturing the energy generated when the vehicle is breaking via some sort of hydraulic pump and then using it again when the vehicle starts from a stop. If this is the case, and, your transaxle is shot, have you considered replacing the transaxle with a hydrostatic motor that could also be used as the pump to capture the energy? A hydraulic pump could be attached to the gas engine for drive purposes. When the gas engine stopped, some sort of relief valve could direct and capture the overrun to a pressure tank where it could then be released when it was time to start the cart again. Also, does a cart really have enough speed and weight to generate usable hydraulic power when stopping? I know some guys who really don't have breaks that work very well at all and they seldom run into anything. lol. just some thoughts, not sure if you can use them or not...

[matt H]

a expanding fly wheel would be easiest

[sheit98carryall]

Originally Posted by jiminpa

I am guessing you are planning on capturing the energy generated when the vehicle is breaking via some sort of hydraulic pump and then using it again when the vehicle starts from a stop. If this is the case, and, your transaxle is shot, have you considered replacing the transaxle with a hydrostatic motor that could also be used as the pump to capture the energy? A hydraulic pump could be attached to the gas engine for drive purposes.

You are exactly correct. We are trying to initially design a "parallel system" which means the entire existing vehicle stays stock and this hydraulic braking system is simply added on top...yet if the transaxle is shot our backup plan was to move to a "series system" where the vehicle is changed to a hydraulic driveline...the series is definitely a more efficient system yet it is also more costly. The goal of our project is to design a system that can be scaled up or down (per vehicle weight) and universally adapted to any given vehicle...that is the reason we are pushing more toward the parallel design.

I guess my next step is to split this case and look for any internal damage. I'm really hoping the people who had this last weren't smart enough to properly adjust this transaxle and that is the source of the problem...though I do not think that is the case.

Thank you for the help everyone, any more advice is still welcome.

[adr]

i hope this worked..... sorry so big a file, couldnt figure out how to just do the untizied axle section only

[sheit98carryall]

Very sweet adr, this will help me out a whole lot.

And no problem on it being the whole file...there is more than just the transaxle broken on this thing lol, it will help me multiple times.

[adr]

anytime... good luck on your project

[jiminpa]

You may also want to check this place out for cheap hydrostatic drive parts, motors, pumps, transaxles, all kinds of stuff you may find useful for this project. Oh, by the way we love pictures here. when this thing gets going post some pictures please.

https://www.surpluscenter.com/