97 EZGO TXT DCS slipping/buzzing with power loss

[joej85a]

Little background: rebuilt a sweet 91 marathon that I got for $40, loved it and drove it like crazy. Some thief thought they wanted it more than me so they stole it. SO, knowing that I cant go without a cart (and neither can my son) we picked up a new cart.

We picked up a 1997 Ezgo TXT DCS regen/cart. When I got it the guy told me he thought it had a stripped hub. Well I got it home and took a look in the rear end, one hub had seized brakes and the hub was cracked. I happened to have ordered two new hubs before my Marathon was stolen, so I had 2 in garage. I adjusted the brakes in, cleaned everything and installed a new hub, torquing to 130ft lbs. I backed up in the cart and it did move but moved slow with a "whirling" or "buzzing" or light "grinding" sound, but a definite slipping. SO I pulled it back in assuming the other hub was stripped. I took it off, looked ok but the castle nut was finger tight, so I installed the new hub, torqued it up and tried it again. During this time I had the charger on the cart. Keep in mind I have no history on the batteries or the cart. After installing the second hub, it moved well, forward and back, no noises, and pretty snappy. So I assumed it was fixed by the new hubs, let the cart charge all night and came back this morning.

So, i check the voltage on all batteries and got right at 6.38 on all batteries after a night charge. I took the cart out, ran well, no noises or buzzes or slipping. Ran it around for about 30 minutes. Up long inclines, etc., did well. I was convinced, again, it was fixed.

Well, I went out again to ride my son around and i noticed upon starts from a stop the slipping or buzzing/grinding sound was back. It moves, but with definite power loss. So I took it to a small knoll and gave it full throttle. The cart stops a little way up the knoll and just makes the whirling/buzzing/slipping sound. Something is definitely spinning, but the wheels dont move. I removed the wheel covers and the axle castle nuts are NOT spinning, they are moving with the wheels as they should.

Here is my question, is it possible this is happening due to poor batteries? Although the batteries check out voltage wise, I dont have anything to test the load/etc. I find it weird that right off a charger, it doesnt do it. Only once i have run it for a while. This is my first TXT/DCS, everything I search says stripped hubs, but i know that is not the case here.

I have the cart charging now to see if with a "full" charge it will make it over the knoll, but does anyone know if it is something else? Thanks all. Joe

[cgtech]

Pull the motor and check the input shaft splines. DO disconnect the batts before remove motor and do mark cables from motor to get them back where they came from.

[joej85a]

Originally Posted by cgtech

Pull the motor and check the input shaft splines. DO disconnect the batts before remove motor and do mark cables from motor to get them back where they came from.

That is on my list to do today, I will let you know the results. As an update, after a full night charge the cart made it over the knoll pretty easily, however in the steepest part, I did hear the roar/slipping sound. So the strange part is that the slipping seems to be worse when the cart is low on power.

Is there some type of safety mechanism on these carts to prevent burning the armature in the event the cart doesnt have the power (ie holding down the throttle and the motor is not moving)?

Thanks all.

[kgsc]

DO flip the Run/Tow switch to Tow Before you touch the wiring. Also be careful with low voltage on that DCS, it will destroy the controller. If you have a volt meter hook it up while driving and see what it reads. The buzzing you are hearing may be the solenoid chattering

[joej85a]

Originally Posted by kgsc

DO flip the Run/Tow switch to Tow Before you touch the wiring. Also be careful with low voltage on that DCS, it will destroy the controller. If you have a volt meter hook it up while driving and see what it reads. The buzzing you are hearing may be the solenoid chattering

Thanks, will do. I will report back after lunch. Thanks all.

[joej85a]

ok, hooked up the meter and showed right at 40.0 volts at rest, right off the charger. Initial full throttle bumps it down to 32v, then levels out at 37v while on a flat surface, full throttle. Long slight incline it runs at 34v. When I took it back over to the knoll, it dropped to 30v and again the buzzing/slipping sound. Circled around and did the knoll again, 28v this time, and a more pronounced buzzing sound when under the most strain and at the point of lowest voltage.

I definitely have a battery pack problem, hope that is all it is. I am starting to think the buzz/whine/slipping is the sound of the motor/solenoid under stress and not getting the voltage it needs?

Thoughts? I still plan on pulling the motor to check out the splines, hope to do that this evening.

[kgsc]

Unless you just want to pull the motor I wouldn't until I got a good pack in there. I would guess you are hearing the solenoid and like I said before low voltage on a DCS will kill the controller

[joej85a]

Originally Posted by kgsc

Unless you just want to pull the motor I wouldn't until I got a good pack in there. I would guess you are hearing the solenoid and like I said before low voltage on a DCS will kill the controller

Heading out to get a load tester. Gonna see if I can find the culprit and check Specific Gravity/water level of each while I'm there.

I'll update this afternoon. Thanks all.

[joej85a]

Ok, update:
So I picked up a battery load tester and tested each battery individually. When first hooked up, each show about 2 ticks over 6 volts. When tested, the front 3 (black ones) dip 1 tick into the yellow (weak). The rear 3 all stayed within the green when load tested. The front three were low on water so I topped them off.

None of the batteries went into the red (bad) area of the meter, so could 3 barely weak batteries be the culprit? Also, the front three (black ones) are rated differently as the back 3. The front are 105's and the back are 120's. Also the front 3 are warped around the positive terminal, you can see in the picture have the plastic has some slight cracking around it.

The guy that I bought it from must have just had a new set of battery cables made, and a couple of the crimps were loose, so I recrimped them.

Anyway, I have never messed with a mix match set of batteries, or "slightly weak" batteries, only ever had brand new ones with my last cart. Do you think this could be where all my issues are originating?

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[joej85a]

Any thoughts? I'm guessing I need at least 3 batteries. Is it worth mixing 3 new with 3 old? Or just bite the bullet and get 6?