In the market for a custom high performance transmission for your modified vehicle? Here are some quick tips to review:
1) You should buy a custom high performance transmission from a local transmission rebuild shop, not online and not out-of-state.
Reason: If and when there is a warranty issue down the road (and with performance transmissions, this is a high probability), you will get much better service from a local transmission shop than you will a out-of-state rebuilder, even if they look great on the Internet or TV. The hassle will not be worth it.
The same applies for used transmissions–always buy locally, and for the same reasons.
Why buy high performance transmissions locally? When you break it, it’ll be a whole lot easier to get fixed or replaced than from out-of-state.
2) Focus on the common failure points of your transmission family. Not horsepower+torque ratings.
Reason: The online companies will try to get you to focus on their horsepower/torque ratings of their “performance built” transmission.
Beware: There is a lot of nonsense in this department when it comes to the actual horsepower and torque ratings of a transmission.
Few of these transmissions have been actually dyno-tested or road-tested for these types of ratings, nor is there an actual standard on testing transmissions (outside of what the manufacturers themselves do at the factory) for aftermarket transmission horsepower and torque ratings.
Many online re-sellers of transmissions are not testing their products at all. They will tell you they do, they may even claim they test them in a vehicle (costs too much), but it is generally well-known that most performance transmissions ship untested.
Claiming to “test in a vehicle” is not a reliable or valid test. It is highly unlikely any company does this on every transmission due to the time it would take to remove and install each one. It would be cost prohibitive. If they claim they test every transmission in a vehicle, think about this: What engine could you put in this “test vehicle” that would bolt to every transmission bellhousing?
Main reason horsepower ratings are BS: Go online and try to find a “transmission dyno tester” that simulates the additional horsepower of a heavily modified engine. They do not exist as of 2019. So the ability to claim (or test) that a performance transmission can “handle a certain horsepower or torque” does not exist, either.
You want a “built” transmission with a warranty? Focus on having a local rebuilder fix and harden the common failure points. That is the best anyone can do, anyway. There is no such thing as a “bulletproof” transmission, as you’ll learn below.
3) Much of the online performance transmission aftermarket is built on hype, not facts.
Reason: Search the online reviews of most performance transmission companies and you’ll find a trove of bad reviews for nearly all of them. Some of the larger ones have hundreds of bad reviews.
The reasons are a combination of:
-The types of abuse these transmissions get.
-The hype of a bulletproof transmission (and the reality that bulletproof doesn’t exist)
-The places not actually building them to the specifications they state.
-The places shipping you a “painted used transmission” versus a performance built transmission.
-The places not actually testing them at all before they ship. In many of these online transmission rebuilders, testing the transmissions is either non-existent or hyped (like claims of testing in an actual vehicle, which is highly unlikely due to the 5+ labor cost hours that would take to install and remove each unit).
-When there is a warranty issue, it is a huge hassle for everyone involved: The customer is mad, the company who sold it is about to pay hefty shipping costs and lose money. The customer blames the company, the company blames the installer or the abuse. Both the company and the customer can be equally correct.
-Performance customers typically not in the day-to-day of installing transmissions, and higher than average improper installations.
-Unrealistic expectations by the customer, based on the “bulletproof” hype.
-The customer saw the company’s transmissions on a TV ad and did not do any further research prior to buying–then regretted it later.
-Performance transmission customers are generally higher-maintenance with higher-expectations who have invested a large amount of their time and parts money into a certain vehicle. Because of that, they usually end up taking up a large amount of a sales rep’s time discussing the various upgrades done to their vehicle and the various upgrades on the performance transmission (no offense, but if you are this person, you know you are). Getting to the point: When said transmission breaks down the road, since their custom vehicle they are building is generally an extension of themselves, this customer takes a breakdown far more personally than the average person.
4) It is not actually going to handle 700HP, even though it says so.
Reason: As you can imagine, GM spends tens of millions of dollars in R+D to build a particular transmission family, such as a 4L60E, to handle a particular horsepower and torque rating.
The performance aftermarket companies advertise they can take a failed transmission core of this multi-million dollar design, add several hundred dollars in parts, and their “built” transmission is suddenly good for 200HP – 500HP more than what GM spent tens of millions to design.
In other words, the performance aftermarket adds 10-15 “hardened parts” to a several million dollar design that has 750+ parts.
Do you believe this makes a transmission go from handling 350 horsepower to 700 horsepower?
Probably not. Does it patch certain common failure points? Sure.
But does it harden the transmission design as a whole to handle 700HP conditions? No.
The remaining unchanged parts, that are not made for 700HP, are still exactly the same. And they are used. And the transmission is now more 5 to 103 times more contaminated (as you will read in #5).
5) Sad truth: A Not-Rebuilt or used transmission is cleaner inside than any “Built” or “Rebuilt” transmission ever will be.
Reason: When transmissions are initially manufactured by the automakers, they are done in extremely clean environments. When the fluid in this new transmission is tested, it has very few contaminants.
Transmissions “rebuilt” by the performance aftermarket have to be opened up and taken apart entirely (unless they are selling you a used transmission straight from the junkyard, which reviews online from some of these companies appear to indicate).
A performance rebuild company starts by taking a failed transmission (a core) and an experienced rebuilder takes it apart and rebuilds it with replacement parts in the same fashion as your local transmission shop would.
Rebuilds are done in extremely dirty environments compared to the automakers, unfortunately, no matter how hard they try to keep them clean.
Studies done by the automotive aftermarket concluded that each and every time a transmission was opened and rebuilt in their testing, the fluid was a minimum of 5 to 103 times dirtier with contaminants than any working OE manufactured transmission that had never been opened. The level of contamination depended on the model of transmission. Certain types were higher than others.
Why is fluid contamination important? Fluid contamination results in
worn valves
bushing failure
burned clutches
solenoid issues
worn gears
valves sticking
rubber seal
accumulator wear
governors sticking (older models)
In summary: Fluid contamination causes of warranty issues. Opening a transmission at all causes instant fluid contamination far higher than what an unopened, used transmission will ever be.
Moral of the story #1: Once a transmission is opened, it will be contaminated inside far more than what a factory transmission ever will be. There is no way around this: Once they are cracked open, they are dirtier, and are more likely to fail and cause warranty concerns.
Moral of the story #2: A low-mileage transmission at a junkyard, that has never been opened or rebuilt, is 5 to 103 times cleaner than the average rebuilt transmission. If you find yourself burning up transmissions quite a bit, buying a used low-mileage transmission may be a cheaper and cleaner and better alternative than buying a high priced “built” performance transmission.
Moral of the story #3: The more filters the better. The OE filter in the transmission was made for OE level contamination. Once a transmission is opened up and rebuilt, use additional supplemental filters to deal with the additional contamination.
6) A local transmission shop/rebuilder will likely give you a better deal, give you better warranty service, do a better job and take their time.
Reason: If you call around to local transmission shops for your performance rebuild, you won’t have to deal with shipping costs. Plus you’ll be bringing your local transmission shop/rebuilder business that they will appreciate.
The online companies are doing high volume: They are in a rush to get them out the door vs. trying to do a quality job.
With a local shop, they will likely take their time and this makes it less likely there will be a warranty issue–but if their is, you are local and it will be easier to deal with.
Shipping costs and time on warranty replacements is a large part of the hassle when it comes to buying a performance transmission online.
7) If you don’t actually need a performance transmission, don’t buy one.
Reason: If your vehicle is heavily modified, you probably won’t be able to buy a stock remanufactured transmission through a reputable company–they only sell transmissions for stock vehicles.
However, if your vehicle is not heavily modified, you are better off not going through a performance company for all of the reasons above.
You will get far better warranty service if something happens by buying a factory remanufactured transmission.
Below is pricing and more info on common transmission models:
Reman Transmission Pricing Table
| Transmission | Street Smart Transmission |
|---|---|
| 4L60E / 4L65E | 2100 |
| 4L80E | 2256 |
| 4T45E / 4T40E | 1935 |
| 4T65E | 1935 |
| 5L40E (Exc. BMW) | 2453 |
| 6T40 / 6T45 | 2432 |
| 6T75E / 6T70 | 2432 |
| 6L80 / 6L90 | 2559 |
| Allison 1000 | 2478 |
| 4R75E/W 4R70W | 2025 |
| 4R100 / E4OD | 2226 |
| 4F27E | 1856 |
| 5R55S/N/W/E | 2203 |
| 5R110W | 2432 |
| AX4N / AX4S | 2037 |
| CD4E | 1947 |
| FNR5 / AWTF-80 | 2148 |
| 6F50 / 6F35 | 2480 |
| 6R60 | 2559 |
| 6R80 | 2559 |
| AWF21 | 2233 |
| 6R140 | 3864 |
| 41TE (A604) | 1905 |
| 46RE (A518) | 2053 |
| 47RE (A618) | 2204 |
| 48RE | 2712 |
| 42RLE | 2152 |
| 545RFE | 2348 |
| 62TE | 2409 |
| 65RFE | 2478 |
| 68RFE | 3543 |
| W5A580 / NAG1 | 2589 |
| Nissan RE5R05A | 2583 |
| Nissan CVT | Call |
| 722.6 | Call |
More Information by Transmission Type
