2003 GEM E825 (2 seater) Brakes pulsating after tire rotation

Hello fellow GEM enthusiasts!

I recently received a 2003 GEM as a hand~me~down from my older brother from SoCAL. I had the beauty trailered to me in Cumming, GA. There was little maintenance performed, it has approximately 4600miles and 2 year old GEL Cell batteries.

I work for one of the largest battery manufacturers so I know about various chemistries (Pb ~ Lithium) but little about electric vehicles. (I look forward to joining in on the battery discussions, I have 30yrs. + on Pb side and 10yrs. + on Lithium side)

So I performed the most obvious maintenance, rotating the tires. However, after taking a test drive I noticed a different noise (apart from other more noticeable ones, we will get to those later).

  1. Slight clicking noise 20 ~ 25mph (from the rear tire area), what could be the cause?
  2. Also I noticed the brakes pulsating more than usual, what could be the cause?
  3. I’ve driven it for several days prior to the tire rotation, is it still save to drive?

Would really appreciate your thoughts/insight/wisdom.
Thank you for your help.

Did the pulsing brakes start after your tire rotation/maintenance?

Did you get into the drums? Maybe you didn’t get a drum on perfectly straight?
I’d start by jacking up one wheel at a time and giving it a spin. Those things should run free and true.

Having a warped brake drum might account for clicking. As the shoes rub, it might rattle the hardware a bit.

It’s just a theory.

The answer to all 3 questions is " it’s a goddamned 03"

Burn it. Connect the insurance money and get a 2006 and up. You will be glad you did


Well, there IS that. I wasn’t going to be so hard on the new guy so soon.

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Gotta break then in right. :crazy_face:

as you guys know its a hobby/passion to tweak, not major form of transportation, its used to transport kids to school/back and visiting friends. something to wrench together while their growing up. So dumping the 2003 is not an option, yet.

I’m sure its got lots of issues (noises), but lets have some fun, memories and trials along this journey.

Now, the clicking is gone, the brake pulsating has diminished, somewhat. Now the other noises, let me research before requesting feedback.

Looking forward to posting and bringing (dragging) you guys along my journey, onward!

Welcome to the group.
If you haven’t found it yet, the search tool is the key to archives that contain thousands of hours of problems and solutions that you will most likely have in common with your new project.

Quite a few have gone down your exact path and now have the wisdom and hindsight that they offer up to save others some headache and future therapy. When someone tells you that the item you are about to pick up is hot, it is up to you to decide if the burn will be worth it.

That being said, the archives are gold when planning your next upgrade. Study up and the kids will have a great time bonding on the project. Be aware that you are working on a car that is 20 years old, based on golf cart designs that are older than that, handmade one at a time, and some parts may be hard to get. Also- being electric in nature, a simple spark of an improperly placed wire can take out some fairly expensive and necessary components.

One more thought -
Since you have some sort of access to some neat battery tech, I’m guessing that is the first thing you dropped in to get this car moving. Feel free to show us what you did and how it is working out for you.

Do yourself a favor and study up on what is going on today with some of the high voltage builds that are running around. Depending on what you have access to at work, Don’t just stop at stock voltage. You’d be surprised how zippy the car is up around 88~98v.

I’ll add my two cents as owner of a 2001 2 seater with a green LiFePO4 green cell conversion (thanks to @Inwo).

Run your VIN at nhtsa.gov and confirm all the safety recall upgrades have been performed.

Strongly consider adding disc brakes to the front and make it stop properly, done on two of them and I’d rate it as high as adding lithium batteries.

You need as much weight as possible on the front wheels or you will constantly spin the tires.

Lithium is definitely a benefit and you’ll enjoy the results but it will always ride like an empty dump truck.

Over torque of the lugs will warp the brake drums or rotors.

Would like to hear about your battery career. It’s a hobby I really enjoy. I go to the international battery show every year in Novi to hang out with my engineer buddies and see what’s new. Look forward to hearing more from you.

We manufacture Lithium batteries for EV, Satellites, commercial jetliner and Industrial (micro grid in small containers for remote areas and war zones), all with different chemistries (Cobalt, Manganese, Iron / specific attributes). Most companies who sell Lithium are assemblers, not manufactures. Lithium is dangerous, volatile and explosive. We also understand the complexities of Lithium, up side (high energy density 3.6volts per cell/light weight) and down side (difficult to recycle, very temperature sensitive, China controls 80% of world resources, very dirty to mine, cost is rising).
Even though i work for a Lithium battery manufacture, its difficult for me to acquire. My division focuses on Pb (2volts per cell), for auto and powersports.
my feeling is we have a place for both Lithium and Pb chemistries for different applications. For pure EV, Lithium is best.
My concern for our group is the understanding of the ALL the complexities/safety parameters that Auto makers take VS. the people within forum scare me. Lithium must be treated like a bomb that simple water cannot put out. We do nail penetration tests, catastrophic failure tests, thermal run away tests, etc…sorry for lecture.
Pls take as much precaution as possible.

my recommendation is to have a fire extinguisher that is rated for Lithium fires on all vehicles w/Lithium batteries.

Lithium-Ion Battery Fire Extinguishers

The following fire extinguishers are specifically designed for use on lithium-ion battery fires which are not the same as standard lithium batteries (use a Class D L2 Powder Extinguisher on standard lithium battery fires).

The dangers of lithium-ion battery fires are with the electrolyte solution in the batteries rather than the lithium salts they contain. Each battery utilises a different electrolyte solution but many contain fluoride which becomes the highly toxic gas hydrogen fluoride (HF) when vapourised.

Lithium-ion battery fires can often build in intensity as they burn (a process known as thermal runaway) and will easily re-ignite if not tackled with a suitable solution.

Class D fires are caused by burning metals that combust easily on contact with air, such as magnesium and lithium. Such specialised fires require a specialised metal powder fire extinguisher to deal with them, and will be required in scientific labs or where manufacturing processes involve the risk of metal fires. For example, aluminium dust or swarf can catch fire, so any process involving cutting, drilling or milling aluminium holds potential risk.


Interesting. Thanks Ikon

Brake pulsation on any vehicle can be caused by improper torquing of the lug nuts–drums or rotors are easily distorted when replacing wheels. You may want to re torque all the wheel in the right sequence and torques.

This is very concerning to me. Drums and rotors, forged and cast of alloys which were designed to withstand and function while under hundreds, sometimes even thousands of pounds pressure per inch and surface temperatures from 400 to 1200 deg F. could simply fail from, an over tightened lug nut?

A structure can deform without permanent damage. As an example, no reputable tire shop will ever use an impact gun to tighten lug nuts. You may see them used to remove wheels but not tighten them.

Yes, but for hardened drums and rotors, this is highly unlikely.
Something thinner and more malleable, like some valve covers, differential covers and oil pans, it is not uncommon due to improper tightening procedures.

I believe you might be referring to improper seating which may cause one “side” of the rotor or drum to be lifted slightly and cause it to rotate in a “wobbly” or elliptical arc rather than a flat circle. If left uncorrected, this condition may cause uneven wear and under some circumstances, typically involving excessive heat, possibly contribute to rotor or drum warping.

This is not an example of a deformed rotor. This is an assertion about the quality and reputability of a shop based solely on the use of a tool. This is a very broad brush filled with a lot of assumptions. Just because they didn’t use an impact wrench and relied on another tool, does not make them immediately honest, reputable or even guarantee proper knowledge and operation of the said tools.

You aren’t wrong, but who the fvck is going to put a $1000 extinguisher in a car? Not even Tesla does that shyt. The greater percentage of Gems don’t even have locking doors…

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I doubt people will even put a $1,000 fire extinguisher in their garage with their Tesla or their GEM/cart.

Could just keep a hook and chain nearby and drag it out of the garage to burn in the driveway…