Monster Transmission & Performance Arvostelua 

This company sold me a transmission that only lasted a couple of months then refused to honor the warranty. They wanted me to remove the transmission and send it to them for diagnosis at my expense and would not honor the advertised warranty. No one should do business with them.

HORRIBLE SERVICE!!!! I ordered my transmission rebuild kit from Monster Transmission for my Ford F-150. I received the kit and my mechanic can't finish because I did not receive the forward clutch discs. Instead Monster Transmission sent me double the amount of reverse clutch disks. I HAVE EMAILED MONSTER TRANSMISSION TWICE NOW WITH NO RESPONSE! I HAVE CALLED 50 + TIMES AND SPOKEN TO NO ONE BECAUSE IT ALL GOES TO RECORDINGS THAT ARE UNCLEAR!
DO NOT BUY FROM THIS HORRIBLE COMPANY!

RoadReady 10L80

Took a few weeks to build. Had local GMC dealership install. They said it went in nicely and quick learned just fine. It is currently being driven lightly to let the transmission learn "learn" the shift patterns. It is gradually shifting smoother every mile I put on it. Went in my 2018 GMC Yukon XL Denali paired with the 6.2 engine. Called 4 transmission sellers, Monster was the only company that had it in stock. GMC was on backorder for 10L80's for months. Thanks to Monster, I didn't have to wait any longer."

"4r100 rebuild kits

My transmission still at the shop. I will let you know when my transmission and put in my truck soon can't wait lol....thanks Sal"

Great company will definitely be back fast shipping an good prices

"Fast great service

Order came very fast and is a great product. No short cuts on their work.very confident that i will not have near the problems as the original one."Order MT-610276

Don't use these guys. There are reputable transmission companies out there. I bought a Monster transmission for my H3 Hummer. It lasted two months and then left me stranded on the side of the road. Waited three months for a replacement and finally went with a real GM transmission that is working great. They shipped a replacement finally and it is sitting on the garage floor... I don't trust it.

Awesome transmissions. Top quality!

Simple to install, only gripe is it doesn’t come preprogrammed"

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."