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4L65E Reman vs Rebuilt vs New Valve Body: What to Buy
4L65E Reman vs Rebuilt vs New Valve Body: What to Buy
Rebuild, remanufactured, or new? How 4L65E TCC bore wear, early vs late EPC style, and your tooling decide which valve body to buy. Read more...
4L65E Valve Body vs Shift Kit: Which One Do You Actually Need?
4L65E Valve Body vs Shift Kit: Which One Do You Actually Need?
A shift kit recalibrates the 4L65E valve body you already have. A replacement valve body swaps out worn bores. Here is how to test yours and pick the right fix. Read more...
4L65E Valve Body Common Failure Points Explained
4L65E Valve Body Common Failure Points Explained
Wrong gear starts, a P1870 slip code, no 4th or delayed reverse: on the 4L65E these usually trace back to one of eight valve body failure points. Here is which... Read more...
48RE Valve Body Bore Wear: Symptoms and the Real Fix
48RE Valve Body Bore Wear: Symptoms and the Real Fix
TCC shudder, a hot converter, shifts at the wrong speed or slipping in reverse once warm: on the 48RE it is often valve body bore wear. Which bores wear, how... Read more...
3.73 vs 4.10 Gear Ratio: Which One Should You Run?
3.73 vs 4.10 Gear Ratio: Which One Should You Run?
3.73 or 4.10? What the numbers mean, how tire size changes the answer, the RPM math, and how to pick the right ring and pinion ratio for towing, fuel economy... Read more...
6L80 P0715: What It Means, Causes, and How to Fix It
6L80 P0715: What It Means, Causes, and How to Fix It
Your 6L80 does not set P0715 - GM assigns P0716, P0717, P0722 and P0723 to these sensors. Here are the real codes, the exact GM thresholds, the 2012 UNIGEAR sensor... Read more...
700R4 vs AW4: Differences, Strength, and Which One to Choose
700R4 vs AW4: Differences, Strength, and Which One to Choose
The GM 700R4 and the Aisin-Warner AW4 are both four-speed overdrive automatics, but one is hydraulic and one is computer controlled. Here is how they differ, how each one fails,... Read more...
700R4 vs TH400: Differences, Strength, and Which One You Actually Need
700R4 vs TH400: Differences, Strength, and Which One You Actually Need
The TH400 is a 3-speed built for torque; the 700R4 adds a 3.06 first and a 0.70 overdrive. Here are the real gear ratios, torque limits, failure modes, and swap... Read more...
4T65E Overheating: Causes, Diagnosis and the Real Fix
4T65E Overheating: Causes, Diagnosis and the Real Fix
A 4T65E that runs hot is usually a hydraulic problem, not a cooling-system problem. Here is how pressure regulator and TCC bore wear chokes off converter and cooler flow, how... Read more...
700R4 vs 4T65E: Differences and Which One to Choose
700R4 vs 4T65E: Differences and Which One to Choose
The 700R4 is a rear-wheel-drive transmission and the 4T65E is a front-wheel-drive transaxle, so they never interchange. Here are the gear ratios, the real failure points on each, and the... Read more...
700R4 vs AODE: Differences and Which One to Choose
700R4 vs AODE: Differences and Which One to Choose
The 700R4 is GM's cable-shifted overdrive with a steep 3.06 first gear; the AODE is Ford's electronically controlled unit with a deeper 0.667 overdrive and a real converter lockup clutch.... Read more...
700R4 vs AOD: Differences and Which One to Choose
700R4 vs AOD: Differences and Which One to Choose
GM's 700R4 and Ford's AOD both added overdrive in the early 1980s using a mechanical throttle valve linkage. Gear ratios, the AOD's split-torque input shafts, what fails on each, and... Read more...
700R4 vs 722.6: Differences and Which One to Choose
700R4 vs 722.6: Differences and Which One to Choose
The GM 700R4 and the Mercedes 722.6 (Chrysler NAG1) solve the same problem two completely different ways. Here is how they compare on gear ratios, torque rating, control method, failure... Read more...
700R4 vs 10R80: Differences and Which One to Choose
700R4 vs 10R80: Differences and Which One to Choose
A GM four-speed hydraulic overdrive against Ford's electronically controlled ten-speed: gear ratios, control strategy, the known wear point on each unit, and which one belongs in your build. Read more...
700R4 vs 6R80: Differences, Strength and Which One to Choose
700R4 vs 6R80: Differences, Strength and Which One to Choose
The GM 700R4 is a cable-and-governor four-speed with no computer. The Ford 6R80 is an electronic six-speed rated near 590 lb-ft from the factory. Real ratios, weights, fluid specs, control... Read more...
700R4 vs 5R110W: Differences, Strength, and Which One to Choose
700R4 vs 5R110W: Differences, Strength, and Which One to Choose
GM 700R4 and Ford 5R110W TorqShift compared: gear ratios, cable versus electronic control, torque capacity, what each one actually breaks, and how to decide. Read more...
700R4 vs 46RE: Differences, Strength, and Which One to Choose
700R4 vs 46RE: Differences, Strength, and Which One to Choose
GM 700R4 and Chrysler 46RE compared: gear ratios, control strategy, what each one actually breaks, and how to decide which belongs in your build. Read more...
700R4 vs 48RE: Differences, Strength, and Which One to Choose
700R4 vs 48RE: Differences, Strength, and Which One to Choose
The GM 700R4 and Chrysler 48RE are both four-speed automatics with overdrive, but nothing meaningful interchanges. Here are the real spec, control and strength differences, plus the diagnostic order for... Read more...
700R4 vs 47RE: Differences, Strength, and Which One You Actually Need
700R4 vs 47RE: Differences, Strength, and Which One You Actually Need
The 700R4 and 47RE are both four-speed overdrive automatics, but they were built for opposite jobs. Gear ratios, controls, torque capacity, and which one belongs in your build. Read more...
42RLE Harsh Shifting: High Line Pressure, Bore Wear, and the Real Fix
42RLE Harsh Shifting: High Line Pressure, Bore Wear, and the Real Fix
A 42RLE that bangs into gear is usually a pressure problem, not worn clutches. Sonnax pressure specs, the P1745 / P0869 / P0933 code logic, the 0.20-1.00 amp circuit test,... Read more...
42RLE No Overdrive: No 4th Gear Diagnosis and the Real Fix
42RLE No Overdrive: No 4th Gear Diagnosis and the Real Fix
Fourth gear is the only 42RLE ratio that uses the overdrive clutch and the 2/4 clutch together. That one fact turns a no-overdrive complaint into a step-by-step diagnosis with factory... Read more...
42RLE P1775 & P1776 Solenoid Switch Valve Codes: Diagnosis and the Real Fix
42RLE P1775 & P1776 Solenoid Switch Valve Codes: Diagnosis and the Real Fix
P1775 and P1776 on a 42RLE are the most misdiagnosed codes on the unit. Chrysler's own tech tip says do not replace the solenoid pack - the switch valve is... Read more...
65RFE vs 545RFE: Differences, What Interchanges, and Which One to Choose
65RFE vs 545RFE: Differences, What Interchanges, and Which One to Choose
The 65RFE is a recalibrated 545RFE, not a different transmission. Here is what actually changed in 2012, the failure points both units share, and which parts cross over. Read more...
4T80E No Reverse or Delayed Reverse: Causes, Diagnosis and the Real Fix
4T80E No Reverse or Delayed Reverse: Causes, Diagnosis and the Real Fix
A no-Reverse or delayed-Reverse 4T80E is almost never a burned clutch. It is a worn pump boost valve sleeve leaking Reverse and torque signal pressure. Here is how to test... Read more...
700R4 vs 4R75W: Differences, Strength, and Which One to Choose
700R4 vs 4R75W: Differences, Strength, and Which One to Choose
GM's hydraulic 700R4 and Ford's computer-controlled 4R75W are both four-speed overdrives, but they are controlled, geared, and rated differently. Ratios, torque capacity, failure points, and which one to build. Read more...
700R4 vs 4R70W: Differences, Strength, and Which One to Choose
700R4 vs 4R70W: Differences, Strength, and Which One to Choose
GM's 700R4 and Ford's 4R70W are both four-speed overdrives, but one is cable-and-governor simple and the other is computer-controlled with far more torque capacity. Ratios, weight, failure points, and which... Read more...
10L90 vs 6R140: Differences, Strength, and Which One to Choose
10L90 vs 6R140: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 and Ford's 6R140 TorqShift are built for opposite jobs. Ratios, torque ratings, the GM feed limit valve recall, 6R140 converter and solenoid traps, and which platform to... Read more...
10L90 vs 10R140: Differences, Strength, and Which One to Choose
10L90 vs 10R140: Differences, Strength, and Which One to Choose
The GM 10L90 and Ford 10R140 share a ten-speed architecture but sit a full torque class apart. Gear ratios, weight, fluid specs, interchange rules and which one fits your build. Read more...
10L90 vs AW4: Differences, Strength, and Which One to Choose
10L90 vs AW4: Differences, Strength, and Which One to Choose
The GM 10L90 ten-speed and the Aisin-Warner AW4 four-speed compared on published gear ratios, torque capacity, electronic control, and documented failure points. Includes the GM feed limit low valve recall... Read more...
42RLE Solenoid Pack Symptoms, Codes, and the Real Fix
42RLE Solenoid Pack Symptoms, Codes, and the Real Fix
P0750, P0846 and P0871 with limp mode on a 42RLE look like a dead solenoid pack. Very often the real fault is corrosion in the 10-pin case connector. Here is... Read more...
10L90 vs A340: Differences and Which One to Choose
10L90 vs A340: Differences and Which One to Choose
GM's 664 lb-ft ten-speed against Toyota's 30-year four-speed truck automatic. Real gear ratios, fluid specs, the 10L90 feed limit valve recall, A340 pressure regulator bore wear, and which one to... Read more...
6R140 Torque Converter Shudder: Causes, Diagnosis and the Real Fix
6R140 Torque Converter Shudder: Causes, Diagnosis and the Real Fix
Shudder at light throttle in a 6.7L Power Stroke is almost always the torque converter clutch, and on the 6R140 it is usually hydraulic before it is the converter. Here... Read more...
10L90 vs TH400: Differences, Strength, and Which One to Choose
10L90 vs TH400: Differences, Strength, and Which One to Choose
A ten-speed electronic overdrive box against GM's legendary three-speed Turbo 400. Real gear ratios, torque ratings, the 10L90 feed limit valve recall, and how to pick the right one for... Read more...
10L90 vs TH350: Differences, Strength, and Which One to Choose
10L90 vs TH350: Differences, Strength, and Which One to Choose
A head-to-head on GM's 664 lb-ft ten-speed and the classic three-speed: real gear ratios, weight and torque numbers, how each unit actually fails, and which one belongs in your build. Read more...
10L90 vs 62TE: Differences, Strength, and Which One to Choose
10L90 vs 62TE: Differences, Strength, and Which One to Choose
The GM 10L90 and Chrysler 62TE are never alternatives to each other: one is a longitudinal RWD ten-speed, the other a transverse FWD six-speed transaxle. Here is how to tell... Read more...
10L90 vs 4T65E: Differences, Strength, and Which One to Choose
10L90 vs 4T65E: Differences, Strength, and Which One to Choose
The GM 10L90 ten-speed and the 4T65E four-speed transaxle share a manufacturer and nothing else. Here are the real specs, the failures Sonnax documents on each, and how to tell... Read more...
10L90 vs AODE: Differences, Strength, and Which One to Choose
10L90 vs AODE: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 and Ford's AODE four-speed compared on gear ratios, torque rating, documented failure modes and rebuild cost. Includes the GM 10-speed recall valve and the AODE bypass clutch... Read more...
10L90 vs AOD: Differences, Strength, and Which One to Choose
10L90 vs AOD: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 and Ford's AOD four-speed sit at opposite ends of the overdrive automatic story. Here is how they compare on gearing, control strategy, torque rating and known failure... Read more...
10L90 vs 722.6: Differences, Strength, and Which One to Choose
10L90 vs 722.6: Differences, Strength, and Which One to Choose
GM's 10L90 ten-speed and the Mercedes 722.6 five-speed compared on gear ratios, torque rating, and how each one actually fails. Includes the 2025 GM 10-speed recall detail and the 722.6... Read more...
10L90 vs 10R80: Differences, Strength, and Which One to Choose
10L90 vs 10R80: Differences, Strength, and Which One to Choose
GM's 10L90 and Ford's 10R80 came out of the same joint program and share a valve body layout, but not their torque rating, fluid, or failure history. Real ratios, what... Read more...
10L90 vs 6R80: Differences, Strength Limits, and Which One to Choose
10L90 vs 6R80: Differences, Strength Limits, and Which One to Choose
GM's 10L90 ten-speed against Ford's 6R80 six-speed: real ratios, torque ratings, the failure point each one is known for, and which unit is the smarter choice for your build. Read more...
10L90 vs 5R110W: Differences, Strength, and Which One to Choose
10L90 vs 5R110W: Differences, Strength, and Which One to Choose
GM's 10L90 10-speed and Ford's 5R110W TorqShift compared on published ratios, torque ratings, fluid specs and real failure points. Which one to choose, and what to replace when either one... Read more...
10L90 vs 46RE: Differences, Strength, and Which One to Choose
10L90 vs 46RE: Differences, Strength, and Which One to Choose
A modern GM ten-speed against a 1990s Chrysler four-speed: ratio spread, torque capacity, the recall history on one and the governor pressure problem on the other, plus what to replace... Read more...
Ford 10R80 Reman Transmission Recall 25E070: Missing T10 Bearing, No Park
Ford 10R80 Reman Transmission Recall 25E070: Missing T10 Bearing, No Park
Ford recalled 34,481 remanufactured 10R80 transmissions under NHTSA campaign 25E070 because a missing T10 bearing can stop the unit from holding Park. Here is who is affected, the symptoms to... Read more...
10L90 vs 48RE: Differences, Strength Limits, and Which One to Choose
10L90 vs 48RE: Differences, Strength Limits, and Which One to Choose
The GM 10L90 is rated at 664 lb-ft against the 48RE's 560-570 lb-ft, but the 48RE builds past 1,000 hp with off-the-shelf parts. Full spec comparison, each unit's real failure... Read more...
10L90 vs 47RE: Differences, Strength, and Which One to Choose
10L90 vs 47RE: Differences, Strength, and Which One to Choose
GM's ten-speed 10L90 is rated at 1,033 lb-ft against roughly 450 lb-ft for the Dodge 47RE, but strength is only half the story. Here are the real specs, the documented... Read more...
10L90 vs 545RFE: Differences, Strength, and Which One to Choose
10L90 vs 545RFE: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 against Chrysler's 5-speed 545RFE: gear ratios, ratio spread, fluid specs, the feed limit low valve recall, the RFE solenoid switch valve bore, and which one is the... Read more...
10L90 vs 65RFE: Differences, Strength, and Which One to Choose
10L90 vs 65RFE: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 against Chrysler's 6-speed 65RFE: real gear ratios, clutch counts, converter specs, and the one valve bore that decides whether a 10L90 core is worth buying. Read more...
10L90 vs 68RFE: Differences and Which One to Choose
10L90 vs 68RFE: Differences and Which One to Choose
GM's high-output ten-speed against Chrysler's Cummins six-speed: real gear ratios, published torque ratings, the documented failure points on each, and which parts actually fix them. Read more...
10L90 vs 4R75W: Differences, Strength, and Which One to Choose
10L90 vs 4R75W: Differences, Strength, and Which One to Choose
GM's 10-speed 10L90 versus Ford's 4R75W four-speed: gear ratios, real input torque ratings, and the two defects that decide the argument. The 10L90's feed limit low valve can wear out... Read more...