Chevy Transmission



  1. Automatic Transmission, Forward Shift Pattern, Automatic Valve Body, Chevy, TH350, 4WD,1982 and later 208NP Transfer Case, Each. Part Number: TCI-311700.
  2. GM Replacement Transmissions Replacing a failed transmission can be very costly, which is why it's so important to find the best price you can for a replacement online. We've listed some of the most common GM transmission part numbers below, making it easy to look up our pricing and place your order.
  3. THM700-R4 - 4 Speed transmission used in GM cars and light trucks with the 2.8, 3.1, 4.3, V6, Chevrolet built 305, 350 and 454 engines from 1982 to 1992. 4L60 - Early 1990's saw the 700R4 renamed to the 4L60, and 'electronic' models were named 4L60E. 4L60 means 4 forward speeds, L = longitudily mounted (rear wheel drive). 60 is the strength.

Chevrolet Silverado 1500 Transmission Guides. Transmission problems? We have diagnostic walk-throughs and repair how-to’s that will keep your Chevrolet Silverado 1500s gearbox humming smoothly. The bulk of Chevrolet Silverado 1500s are equipped with automatic gear boxes that require little to no maintenance.

Chevy Transmission Identification and Decoding

General Chevrolet Transmission Identification

Transmissions are marked and identified by:

- Casting numbers on the case, extention housing and side cover
(on manual trans).
- Date Casting Codes
- Assembly Date Code Stamping - can be stamped anywhere..
- Chassis Vin Number stamping - beginning in 1962

Transmissions have RPO numbers, usually beginning with 'M'.
This page covers automatic trannies. Go here for Chevy Manual Transmission Identification.

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Chevrolet Automatic Transmission Identification & Description

Automatic transmission types are generally identified by their pan shape.


The THM200 and the THM250 have pans shaped like a THM350, HOWEVER, the THM200 will have the words HYDRAMATIC DIV. and METRIC stamped into the pan.

Chevy Automatic Transmission Description & Usage
THM200 - Light duty, 'metric' 3 speed transmission.

THM250 - Used in small 4 cylinder cars (Vega, Sunbird, Monza) from 1973 to 1981 and some Nova/Camaro/Chevelle 6 cylinders in 1974 & 75. The 4 cylinder models have 4 large cooling holes near the torque converter, while on the 'bigger cars' there are no cooling holes.

THM200-R4 - Used in GM rear wheel drive cars with the 3.8 V6, 305 & 350 Olds and 301 pontiac from 1981 to 1989. This is a 4 speed, overdrive unit.

THM350 - Medium duty 3 speed trans used from 1969 to 1989, Used in Buick, Olds, Pontiac and Chevrolet cars and Chevy & GMC light trucks until 1987. Generally used in straight and V6 and small block engines. Generally able to handle up to 400 foot pounds of torque.

THM375B - This trans is identical to the THM350, but is considered a heavier duty transmission.

THM375 - This transmission is a derivative of the THM400 sharing the external appearance of the 400. It'll be marked 375-THM on the bottom of the tailshaft housing. It's a light duty version of the THM400, has ABSOLUTELY NO RELATION to the THM375B, and was found in 1972 to 1976 full-size cars. The Turbo 375 was modified to accept the Turbo 350 driveshaft yoke.

THM400 - The THM400 was GM's Heavy-duty 3 speed transmission used from 1964 to 1990. Used on large displacement, high torque engines and engines with towing packages. Generally found in Chevy & GM trucks, cadilacs and large displacement engined, full size GM rear wheel drive cars.

THM700-R4 - 4 Speed transmission used in GM cars and light trucks with the 2.8, 3.1, 4.3, V6, Chevrolet built 305, 350 and 454 engines from 1982 to 1992.

4L60 - Early 1990's saw the 700R4 renamed to the 4L60, and 'electronic' models were named 4L60E. 4L60 means 4 forward speeds, L = longitudily mounted (rear wheel drive). 60 is the strength rating (less than the 4L80).

3L80 - The 3L80 is a renamed THM400, used in the early 1990's. The 3L80HD would be the THM475 (heavy duty unit).

4L80 - An overdrive model of the THM400. The 4L80E would be the 'electronic' model.

Transmissions with a suffix of 'C' on the end of the type (THM200C) indicate the transmission has a lock up torque converter.

Chevy Transmission

Chevy Automatic Transmission Identification: Other Methods

Some transmissions have a code stamped onto them. Others have a tag rivited to the case.

Most transmissions will have a 'source serial number' (chassis vin) usually found close to the transmission code. This number will contain division ID #, model year, assembly plant and production sequence (last 6 digits) of the VIN stamped onto the transmission. Example: 19N500001. The source serial number is from the CAR the transmission originally went into, NOT the assembly plant.

Location of source serial number

On the THM350, the VIN will be stamped on either the drivers side housing near the shifter, on the right side of the housing just above the pan, or on a boss behind the bellhousing flange on the passenger side of the transmission.

Automatic transmissions for saleChevy

On the THM400 the VIN is stamped on a machined surface just above the pan on the drivers side.

On the THM200-R4 the VIN is stamped onto the housing towards the rear of the pan, on the drivers side.

On the THM700-R4 the VIN is either stamped onto a boss behind the bellhousing flange on the passenger side, just above the pan on the drivers side, or just behind the governor cover, stamped vertically where the case meets the tailshaft housing.

Transmission

Prior to 1967, transmission ID numbers contained the plant prefix code, month and date of production (expressed numerically) and a shift code (D = Day, N = Night). From 1967 on, the ID number contained the transmission type or plant prefix, Date (coded below) and a shift code. The constants in decoding the trans ID number are the date the transmission was produced.

Pre-67 Example: C213N - (C = Cleveland Powerglide, February 13, Night Shift)
Post-67 Example: P9E03 - (P = TYPE, 9 = year (1969), E = Month, 03 = Day of Month)

Month code: (NOTICE this is NOT in alphabetic order)
A = Jan, B = Feb, C = Mar, D = Apr, E = May, H = Jun, K = Jul, M = Aug, P = Sep, R = Oct, S = Nov, T = Dec

The dropbox contains Camaro transmission codes. What SHOULD have been installed, or what was offered for the year selected.

Chevy Automatic Transmission For Sale


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Last updated: 10/20/2011
Author: MadMike Maciolek


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There seems to be a link between the Chevy Silverado 1500 and transmission problems. This is made even more concerning because Consumer Reports gave the 2021 Chevrolet Silverado 1500 the lowest predicted reliability rating out of every pickup truck.

Does the Chevy Silverado 1500 have transmission problems?

If you take a look at the data provided by Consumer Reports you’ll see that the 2021 Chevy Silverado 1500 only has a score of one out of five in terms of predicted reliability. This score is based on survey data that Consumer Reports collects from thousands of drivers.

Silverado owners reported potential problem areas as well as how satisfied they are with their truck. Then the ratings are compiled based on 17 potential trouble areas and a 100 point scale to provide fair scores. How to share desktop in teams. One of the most significant trouble areas includes major and minor transmission issues for the past eight model years.

Also, Car Complaints serves as a forum for truck owners to report issues they faced with their Silverado models. A variety of transmission problems have been reported there and provide a little more detail about the issues.

2017 Silverado transmission problems

The 2017 Chevy Silverado 1500 has 62 transmission problems reported. The most common issue includes surges and jerking. One driver didn’t notice any issues until a few weeks after buying their Silverado when surges in the transmission could be felt.

They went to a dealership and was told that the truck needed to learn their driving habits. They said to bring it back if the problem still occurred in a few weeks to fix the torque converter. The driver did as instructed but was then told that the issue was caused by the automatic 4WD, and switching it to 2WD should fix the issue.

Saraswatichandra apni tv. RELATED: The 2022 Chevy Silverado is Finally Receiving Interior Upgrades

Another driver had their transmission replaced when their truck only had about 66,000 miles on it. The replacement wasn’t covered under warranty and cost about $3,000. They were frustrated because their transmission didn’t last longer than two years and four months.

Other transmission problems with the 2017 Silverado include hard shifts, clunking in low gears, hesitation with accelerating, metallic bang noises, and the StabiliTrak light coming on on the highway, causing the truck to slow down.

2019 Silverado transmission problems

If you skip ahead to the 2019 Silverado 1500, you will find five transmission problems. This is an improvement from 62 problems with the 2017 model. However, more issues may get reported as the 2019 models accrue more miles.

Chevy Transmission

The most common issue includes slamming into gear. One driver noticed that their Silverado slammed into first and second gear after a slight pause that allowed the engine to rev. Another driver noticed that their truck slams from reverse into drive. It also surges forward upon lightly accelerating with grinding noises.

Also, if you go back and look at previous models, there are even more reports of transmission problems. The 2014 Silverado has 22 transmission problems reported. The 2012 Silverado has eight transmission problems reported and more.

According to GM Authority, in 2019, GM began using a new type of Mobile 1 automatic transmission fluid to correct problems. Also, a TSB (Technical Service Bulletin) addresses torque converter clutch (TCC) shudder conditions for the 8-speed GM transmission. So a fluid flush or replacing the TCC could be the answer. It’s currently unclear if the 2020 and 2021 Chevy Silverado 1500 models have the same problems.

Chevy Transmission Md8

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