Monster Transmission & Performance Reviews 229

When a company has as many 1 star reviews as this one does, I really should have walked away. But transmission replacements for a fully original, great condition 1984 Cherolet G20 are hard to come buy. I bought an upgraded package as a gift for my father in law. Since it was original, we live in Wisconsin, and he had cancer, its not driven frequently. Within the 3 year warranty period and UNDER 400 MILES, the first transmission locked up. They replaced it, but I asked about an extended warranty because they didnt get me the transmission until after snow and salt were on the ground. One of their techs told me "i drive my 60s mustang in the winter in Michigan all the time, its not that big of a deal." My father in law died in February, without ever driving his van again, and on it's second trip out to pick up his grandchildren from school and bring them joy in Grandpa's van, it started shaking in OD. When I called, Monster refused to help, stating I didnt buy the extended warranty(that I was never offered). They have no respect for classic cars, horrible customer service, and even worse product. Stay far away!

Monster took our money (over 6K), then told us they did not have the transmission we purchased. They attempted to upsell us another transmission for more money. We asked for the order to be cancelled and our money refunded. We also called the shipper to ensure they did not ship the transmission we did not want.
We are now nearing two months after cancellation with no refund. On a phone call, a month ago, we were told it was going to 'bookkeeping' to be refunded.
This appears to be an insolvent company using the money of others in a "Ponzi" scheme. Why else would we not have been immediately refunded for an item that was never shipped to us? No communication, money, and hours of time gone. The truck is still broken, affecting everyday life immensely.

"StreetMonster Dodge 68RFE

We got this installed and it seems to work great! Fingers crossed that is lasts long. We did purchase the extended warranty just in case. The people at Monster Transmission were very helpful and our order came quicker than expected. Now we will see how well the core return goes."

I purchased a 6l80e transmission in April '25. I paid extra for an already programmed tran but after installing we realized it was not. After a couple weeks of driving to work I was noticing it seemed to be shifting at incorrect times. Shifting at high rpm or shifting down while cruising randomly. It went back to the shop and they diagnosed a bad internal sensor, so we contacted Monster that summer assuming it would be an easy swap. It was not. They ran me in circles for months, taking days between responding to messages and asking for hours of nonsensical work and pictures from the mechanics dealing with the truck. They tried to drag it until I gave up but I reached out every few days until December, as they 'reviewed' the claim. Finally, with the notice of nearing legal action, suddenly they can replace it. But would not do a return. I had no choice to agree, despite my lack of trust at this point,so they came and picked up the transmission a week or so later. Without dropping off another one to install.(february '26). Instead they take the tran for weeks before returning with the same transmission! All we could do is put it in and see, and after paying to get it programmed again... IT WONT GO OVER 30MPH. Around 30 mph it starts making a loud grinding noise that is terrible. Its way worse than before and possibly deliberate. Since, I have tried reaching out multiple times a week and am either blocked or ignored. I had to purchase another transmission as my truck has been sitting over a year thanks to this mockery of a company. Save Yourself

I recently purchased and installed monster 6l80e street monster trans. The truck did not run right from day one. Monster wanted me to remove and ship trans back for warranty work. As this was more expensive and time consuming than having my mechanic tear down and inspect i chose to void warranty and authorized my mechanic to tear down and I sure am glad I did after seeing what they did or DIDNT do. Metal shavings in pan, bad pr valve, cracked drum, less than oem quality burnt clutches. Damaged sprag, remanufactured techm that was not functioning correctly and these people say all transmissions get bench tested although my mechanic found the issues in the first 10 minutes of tear down and testing. Save your money save the headache and stay away from these scam artist's!!!!

I had a very challenging experience with this company overall due to poor communication, delays, and a lack of professionalism throughout the process. In particular, the general manager was completely unresponsive to emails and phone calls, which made resolving concerns unnecessarily difficult and added to the frustration of the experience. There were several moments where expectations were unclear, and resolving issues became unnecessarily difficult. I believe there is significant room for improvement in customer service, responsiveness, and internal organization.

That said, I want to specifically recognize Krystal Schmidt for her professionalism and support. She was by far the most helpful person I interacted with during the entire experience. Krystal was responsive, respectful, knowledgeable, and genuinely worked to assist me despite the broader issues I encountered. Her communication and dedication made a difficult situation much easier to navigate, and she deserves recognition for the way she treats customers.

"Sportmonster 6l80 4wd
I received my transmission approximately 3 weeks after ordering, I found the box had been hit during shipping, so I checked it over to find the bell housing was broke and one of the gallon jugs of transmission fluid was broken open. I refused to unload it and told the trucking company to bring it back. I called Monster and sent them pictures. Krystal got right on it and started the process to get me a replacement. She kept in contact with me on any updates as they were trying to rush me a replacement. Costumer service was excellent. I received another transmission within a couple Of weeks. I installed it and put it to the test. So far no issues. I’m very satisfied with this company. A good idea to check your order before unloading it…."

I sent my Transmission core in 3/14/26 I still haven’t received my refund on my Transmission core and it is now 5/7/26 I have called and called left messages sent emails no response no message back nothing

The people were so polite and knowledgeable. They helped me 💯 percent. My transmission came in today just as they said it would be. Will definitely use again. Thank yall so much.

I am very pleased with my transmission and the shipping! JC was a lot of help in my order and what I needed for my truck thanks to him I’m all set on my project! Thanks guys."

The unit showed up in a timely manner an was in a plastic container. Did have two quarts of fluid that had leaked in to the bottom. The unit was clean and after installing it vehicle is running an driving great. No issues with install and this makes the 5th unit I have put in different vehicles."

Absolutely horrible company. on or around the beginning of March, the transmission "banged" out of 6th down to 4th gear, and immediately the check engine light came on. The code was P0765, shift solenoid D. Per Monster transmission and BD Diesel's instructions, I had my mechanic do the initial diagnostic tests. Following that, they wanted the trans fluid drained, pictures sent in, etc., which showed metal shavings in the fluid, and pressures above where they wanted them. At that point, they told us to send it back to them. On or about 8 April, again at their request, we sent it back. During that time they ignored emails and phone calls, then yesterday they finally emailed to say that there is nothing wrong, and that I owed them for labor for diagnosing and shipping to get the transmission back. They haven't responded to the last 3 emails over the past 24 hours, and have refused to acknowledge any possibility of a refund, or explain how they can demand we send something to them, then deny anything is wrong with it. I've been without a truck for almost 2 months now, and it's clear that they do not stand behind their product, their warranty, nor do they care about the consumer after they've gotten their money. I have all the email traffic to support this statement as well.

I bought a new transmission from them it failed within the 1st 6 months less then 10,000 miles After months of being put through hell! they warranty it 2 months later i received a replacement which was left out in a parking lot by their driver, That Transmission lasted 5 miles!
having to hire a lawyer because of no response. STAY AWAY FROM THIS COMPANY NOTHING ON THERE SITE IS TURE

Great experience! Great product! Highly recommend. Ask for T-Mac.

"High quality build
Recommend to purchase great service top notch"

We ordered this transmission and it arrived quicky. Very happy with the shipping speed and customer service support."

Not had success calling them directly as their management won't return calls so I google searched and finally got through to the real owner of Monster transmission which is based out of south florida. They are called Hidden harbor capital partners in Boca Raton. After speaking to someone at their main office I finally got a resolution and wanted to share this experience as I'm sure others are having the same problem from what I read online.

Very good transmission. Lived up to my expectations!!

Customer service was great and shipping was fast and professionally packaged! Transmission was built to the highest quality standard!

These transmission are built to handle what you throw at them.