I noticed that when going about 20 mph and I let off the accelerator I get a “bruuuuck bruuuuck chicken” sound when the car is free wheeling and the accelerator is partially engaged. When ever the unit is accelerating or decelerating the transaxle is quiet. One of the members said the rubber bumper where the motor connects into the top gear maybe worn. The car has 2500 miles on it. It’s not loud but wondered if this is normal?
Wear is common on the splined connection between the motor and the transmission input shaft. The rubber bumper is there to take up the lash between these components. If you feel a clunk every time the throttle is applied, there is slop in the drive line. If you are lucky, replacing the rubber bumper will eliminate the slop. They only cost a few dollars, so keep a few on hand. The rubber bumper is replaced anytime the motor is removed. If the splines on the shaft are badly worn, the shaft must be replaced. I assume the female splines on the motor are stronger because I have never seen them wear even on a GEM that had severe wear on the input shaft. The shaft is available as a component part, however, several ratios have been used over the years. The different ratios are not interchangeable. The shafts retail for about $300 from the dealer and can be hard to get. The ratio should be listed on the body of the transmission. There is a member here who is selling transmission parts. Changing the shaft is not a hard job for a mechanic. The o ring and bearing are readily available from industrial suppliers. our four GEMs have all had the bearing replaced due to leaking oil into the motor.
Other possible problems could be lack of oil in the transmission, loose CV joints, or loose bolts in the drive train.
Thx. I think the last owner replaced that bumper. I read where one mechanic said it was to load the rear thrust bearing of the motor
[QUOTE=wmgrd;12221]That is not a normal sound. Check your CV Joints, and the 3 bolts holding the motor in place. Some bolts have backed out causing more backlash on the Female motor spline and the Male output shaft. It might even be just your rubber bumper bushing which goes in the spline of the motor. you can PM me i carry the rubber bushing and Gem rebuilt kits for the gearboxes. When you remove the motor check for play in the output shaft on the gearbox where the motor mates. If you have to much play in the output shaft replace the bearings before it breaks the gearbox casing. Once the casing or housing is broken you will not be able to rebuilt or repair it. You will need a new gearbox.
Thx. I will do that. What is your price on the bushing?
The motor is tight to the transmission. The half shafts into the transmission have some play in them. When I grab them I could move them maybe a 1/64 of an inch. Is the wear usually on the shafts or the transmission output splines. Can I run these for a while? Are they hard to change out?
The motor is tight to the transmission. The half shafts into the transmission have some play in them. When I grab them I could move them maybe a 1/64 of an inch. Is the wear usually on the shafts or the transmission output splines. Can I run these for a while? Are they hard to change out?[/QUOTE]
I think I will try the bushing first, then order the rest. Let me know how I can contact you. My GEM is a 2002 e825.
[QUOTE=wmgrd;12229]That play is close to normal. The wear is the bearings specially if you see oil inside the motor or bleeding from the trans output shaft. it would be safe to replace the bearings that go on the output shaft. I have only see the splines damaged from the motor bolts backing out and the motor not aligned straight causing the motor and trans output shaft to have uneven wear to stripped splines on the output shaft. The motor female splines always survies and the male on the trans gets stripped. Start with the most lowest cost part and work from there.[/QUOTE]Marlon,
Have you thought about putting together a preventive maintenance list of simple things to check on a schedule to avoid this type of preventable damage from occurring. I’d think it would be a shortish list, but well worth the effort to go over every few months or so.
I replaced the bumper and it did get rid of some of the noise. It was totally quiet for about 3 miles then some of the gear backlash came back but quieter than before. When I took off the motor bolts there were no washers. I noticed on the new 2012s the bolts have washers on them. I put the bolts with new washers and a drop of blue locktight on each thread. I also noticed there are six holes so you can rotate the motor 30 degrees or so if you need to. I checked the output shaft and it seemed ok and was dry. I could hang the motor on the shaft to get the screws in. The splines were dry with some red powder on them (rust?) Anyway I took a rag and cleaned the output shaft off and used my shop vacuum to blow all the dust out of the motor. The commutator end bearing had enough play in it so that the armature would touch the field coil heads on the transmission end. When in the turf mode the transaxle is quiet except for the gear whine. In road speed mode I get a little rattle as the gears take up and release slack when the accelerator is partially depressed and when coasting between 15 and 22 mph. I replaced the 10" tires with 12" tires so my top speed is near 30 mph. I wonder if this exaggerates the transmission slop/noise? Anyway I am green as grass in experience here so your thoughts are very welcome.
The transaxle can be installed with basic tools. If your issue is stripped splines on the input shaft where the motor attaches, the shaft can be replaced without removing the transmission. I have done this numerous times. See the third paragraph in my post below for part numbers and replacement procedure.
With this hot weather the ring and pinion gears seem to have a excessive amount of gear play. I think on this differential they are straight cut and not really a (ring and pinion grear). Straight cut gears are noisy anyway. On colder days it seems to be quieter. I am running 90 oil. I may need to buy a new transmission. I don’t think I’m up to doing a complete transmission overhaul. I could replace both the armature and output bearing but they seem to be OK.
Let me pick your brain another time. When I replaced the rubber bumper that seemed to quiet the drive. Then after a couple of miles the gear lash came back. I ran the motor with the wheels off the ground and noise seems to be coming from the top of the gearbox. The output shaft bearing was not leaking oil. (the inside of the motor was dry and had no metal shavings) The motor spline and output shaft spline seem to be tight and not damaged. I am wondering if replacing that bearing might help. It looks like there is a idler gear between the output grear and the big gear. Does that bearing ever fail? It is possible to change that bearing by take off the rubber cover midway up the casting?
Greetings gentleman. New to the forum. I have a 2001 with the same noise. We replaced the bumper two days ago also with the same results. When I jacked it up, I noticed a small amount of oil on the transaxle where it meets the motor. The old bumper was ground down to approximately half the height of the new replacement. I’d post a picture but I don’t have the rights yet. Although the majority of the noise is gone, there is still a low grumble. Nothing’s ever dripped onto the garage floor but still seemed to be new oil. I see a large parts bill in the near future.
I have never needed to replace the smaller input shaft bearing that goes on the inside of the transmission. This bearing has always come out with the shaft whenever I’ve had one apart. The bumper will always be smaller when removed because the assembly compresses it.
Yesterday I replaced both half shafts and allot of the noise and looseness went away. I can still hear the backlash in the transmission…not bad but noticeable. Has anyone replaced the input shaft due to wear on the top gear? Oh yes I had bought a motorcycle/atv jack from Harbor Freight $70 to work on my motorcycles. Wow it is great for lifting the front end of the car. A 15" Cresent wrench open jaws slides neatly between the transmission and inter CV knuckle to pop it loose. Just tap the end of the wrench to force it out. I found that taking the bottom end rather than the top end of the shock loose better to get the clearance to pull the axle out. The other thing is that by rotating the steering wheel you can get more clearance to pull and push the wheel spine end through the backing plate. The manual says it’s a two man job…not so.
I have not seen any gear wear on the inside of the input shaft. The only wear on four GEMs in ten years has been to the splines where they meet the motor and the large bearing where the shaft enters the transmission.
To address an earlier statement about gear lash, I have discovered that extreme high temperatures actually causes engine and transmission components to expand slightly. This results in less gear lash and noise. I know this from serving two tours as a mechanic in Iraq.
I have both the motor brush end bearing and the large bearing where the shaft enters the transmission. After reading my messages do you think this is worth trying? When I first put the rubber bumper in it seemed to quiet the transmission down for several miles. The spline fit seemed to be good between the motor and the shaft. When I tilted the motor up on end there was enough play in the brush end bearing to allow the armature to touch the field poles on the spline end. There we no filings and the motor doesn’t seem to be dragging internally when the shaft end in holding the armature in place.
Check for a thrust washer behind the bearing at the commutator end (where the brushes go). This looks like a thin wavy washer. Get one just smaller than the outside diameter of the bearing. I have had to install these when a motor has too much end play. McMaster and other industrial suppliers sell these. If you have the motor out, you must again replace the rubber bumper as they can only be used once.
Thx. I checked the motor and transmission bearing and they seemed to be ok. I put a new bumper in and lubricated the splines with a thin coat of moly grease. I wonder if the splines were dry it would stop the bumper from doing it’s job. It seems to me that the splines should be able to move to take up the end play. This took care of the noise but I wonder how long its going to last?
I can’t seem to figure out how to send a PM to you, if you could find the time would appreciate hearing a way to get one for a spare. I am REAL far from any dealer! thankya
Okay, never mind, another reader of the forum told me where to get them and I ordered a couple. Thanks to all you folks who maintain and support this resource!
[QUOTE=wmgrd;12228]I just sent you a private message. Look at your right side of the top page where it says Welcome Chuckkent, and has date and time. Below that says private message click on that look for your inbox you should have the message.
Motors - Electric Golf Car and NEV Parts for EZGO, Club Car, Yamaha and Tomberlin They sell the bumpers (0313-00168) for $7.30 ea. It’s about $10 shipping grrrrrrrrrr so I ordered two.