Bought a transmission and 3 year warranty 12-20-23. Took 2 years to contact warranty and actually my cousin who does business with them got a hold of his contact at monster. His shop was going to do repairs but was over booked so I found a new shop to do repairs. New technician decided to voided my warranty 6 months early because vehicle was being driven even though transmission was faulty when purchased and had been driving. Now I'm responsible to cover $740 to fix the faulty parts the transmission had when purchased. Had a one time no questions asked replacement wowarranty. Would not recommend them and I regret not get a built transmission from summit for less money. Thanks tech department for the faulty transmission and then sticking me with the repair bill. Transmission stick makes the same noises it was a month after original install because a faulty bearing and seal.
We are disappointed to read your review, as it does not accurately reflect the documented history of your warranty claim.
Our records show that your initial warranty claim was opened on **September 21, 2025**, for a squealing noise from the tailshaft. The following day, your claim was submitted to the manufacturer, and by **September 23, 2025**, the vendor had spoken directly with your repair facility and authorized a field repair. At that point, the expectation was that the repair would be completed by your chosen shop.
Approximately **six months later**, on **March 20, 2026**, you contacted us to advise that the repair had still not been performed and that you were looking for another shop. You later informed us that your cousin's shop would complete the repair, and no further updates were received.
When you contacted us again in **late June 2026**, you advised that another repair facility would now be performing the work. At the vendor's request, we confirmed that the vehicle had continued to be driven since the original claim was reported. You advised that it was your work truck and provided the current mileage. Based on that information, the vendor determined that the vehicle had been driven **more than 9,100 additional miles** after the issue was first reported.
The warranty was **not** denied because you selected a different repair shop. It was denied because the vehicle continued to be operated for thousands of miles after the concern was identified, despite a repair path already being authorized. Under the terms of the warranty, continued operation after a known issue is reported constitutes grounds for denial of coverage.
Regarding the **One-Time No Questions Asked Replacement**, that program is intended for eligible warrantable failures. It does not apply to claims that have been denied due to the warranty terms no longer being met.
We understand this outcome is frustrating. However, our decision was based on the documented timeline, the mileage reported, and the vendor's warranty determination—not on an unwillingness to assist. Throughout the process, Monster Transmission continued to communicate with you and the vendor in an effort to facilitate a resolution.
Gave them a call they told me what I needed and were very helpful with everthing
We ordered a replacement transmission from Monster transmissions June 27th. Our 2018 Chevotlet Silverados 6 speeds transmission basically went kablooey. Thus far, Monster transmissions has been available to support and questions along the way. We are impressed. We are praying this momentum continues as we now navigate installing the new unit and using their provided tool to program it.
So far so good regarding our purchase of our new transmission. This far excellent support.
My transmission temps while driving through the mountains pulling our small travel trailer were getting about 220f and after installing this cooler they dropped to about 180f. This has made a big improvement on our 4L60 when shifting on steep grades.
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.
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
This is perfect for me as I do my own truck repairs at home. This was so easy to use and reprogrammed my transmission in my driveway. I would highly recommend for anyone doing a 6L80 at home and doesn't want to tow their truck to the dealership to have it programmed.
I bought a transmission from this company, and it was a great experience. The staff was professional, helpful, and knowledgeable throughout the process. The transmission was exactly as described, worked perfectly, and the price was fair. I would definitely recommend them to anyone looking for quality parts and excellent customer service.
The 700R4 4th gear torque converter lock-out kit works well. Couple notes: the toggle switch & bracket needed for in the cab is not included…you will need to source it yourself; Also the “install” video mentions test powering the SV and listen for the “click”…my tranny did not click…and I suspected the SV was bad…but not so…went with full install and everything worked when I went for a test drive.
Great an fast service will shop again if needed
Very satisfyed so far will update when programmed an running
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 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.
Awesome transmission. No issues, works perfectly. High quality beast. Thank you!!!
I've been purchasing monster transmissions for years and every single rebuild has surpassed expectations! To top it off, the warranty program offered is the best I've ever found. I highly recommend monster to anyone I know that is in need!
I have roughly 800 miles on the new trans and converter. Shifts smooth and clean. No vibration/shudder,no gear hunting. Pretty smooth process very happy
I must say I’m very impressed with the quality of service provided by monster transmissions. The experience on the phone with the knowledgeable sales rep was a sure one-on-one experience answering any questions I had tailored to my specific needs. Just got the transmission put in so I haven’t put it to work yet but I feel like a little kid on Christmas just waiting to unwrap that present
Simple to install, only gripe is it doesn’t come preprogrammed
Installed the sport monster in my 2004 GMC Sierra 1500 with the 5.3 that I have done some work too about three days ago so far I’ve put about 50 miles on it. I did the hot flush on all the lines and remove the old cooler and went with the oversized Mishimoto trans cooler. Running the lube guard trans fluid that they sent with. It drove about 50 miles so far going to do the 500 mile break-in. Its shifts really firm and I’m really pleased with everything. No leaks. The stall converter drives great and locks up great. I am pleased with my purchase so far! Excited to break it in and see what this thing will really do!
Installed with the new transmission. All the instructions were easy to follow. Hoping everything works as expected.
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.
Easy to order. They answered all my questions. Shipping was fast. Drives better than when I bought it new.
Best experience with purchasing. Great customer service, personalized attention. Quick shipping. Solid product. Would use again without reservation.
Got this transmission back in February and since put about 6k miles with some some light towing over mountains and it seems great so far it is a little louder than stock when shifting at low rpm it kinda chatters but other than that it’s been great
