What Is the Best 10 Bolt Gear to Use With 1975 Super T10 in a 1970 Chevelle UPDATED

What Is the Best 10 Bolt Gear to Use With 1975 Super T10 in a 1970 Chevelle

At that place are a couple of unlike debates that typically occur when a bunch of automobile guys gather. The first and most obvious has to practice with the size of a car's engine. While the big-block vs. modest-block variable is one that has two groups of passionate followers, the other reflects the way in which the driver selects manual gears. The discussion well-nigh whether to utilise a four-speed or an automated transmission has been going on for as long as anyone tin can recollect, and nosotros see no terminate in sight.

While the Chevy four-speed manual transmission was a staple in many muscle cars, even many of the General'south "other" car models were equipped with a manually operated gear selecting device. Even so, finding one of these transmissions now at a swap meet or salvage yard is getting harder and harder. If yous do happen to stumble across Chevy four-speed at a swap meet, do you know what y'all are really looking at? Did you know that there are various models that were used in various cars? Hopefully, this guide can help you decipher what gearbox you lot have located if you're in need of a Chevy four speed, or if you are fortunate enough to happen across 1 stashed away in a barn somewhere.

Many enthusiasts feel that for a car to be a true muscle car it must have a four-speed manual.

Gear Selection Varied

During the run of General Motors' inclusion of four speeds in their cars, there were three variations possible. First came the Borg-Warner T10 commencement in the late '50s. This early box began its career being placed in the Corvette. By 1963, the Full general had developed and worked with the Saginaw Corporation to develop a proprietary Chevy 4-speed (based on components used in the Borg-Warner transmission). Non only were they both popular transmissions in muscle cars and Corvettes, but many were fifty-fifty used after the muscle motorcar era. We accept salvaged more than than 1 Saginaw from cars like the Vega and Monza.

Borg Warner once once again started supplying four speeds to GM in the early on '70s with the release of the Super T10. This was used in A-body and F-body cars and Corvettes into the early '80s.

Nosotros've sourced more than one Saginaw from Vegas in junkyards. Of course, that was many years ago.

Depending on how yous ordered your muscle car in the '60s and early '70s, yous might have even benefitted from the famous Muncie transmission. It's no secret that the Saginaw and Borg Warner transmissions were not built to handle the kind of power that a Muncie transmission could withstand. Only in non-performance applications, they were however a expert Chevy four-speed transmission. Keep in listen, if you programme to drop one in a vehicle that makes more power than it did when it was stock, you might want to consider going with the Muncie if y'all program to beat on it. Basically, if y'all are installing ane or the other in a car that will exist a squeamish commuter and see only minimal, spirited gear grabbing, both the Saginaw and the Borg-Warner tin be a good and less expensive culling to the more than robust Muncie.

Images courtesy of Hurst Shifters

Every bit a dominion of pollex, the Saginaw and Borg Warner Chevy 4-speed transmissions should alive a long and happy life when used in cruiser applications. If the car has high-functioning upgrades that substantially enhance the engine'southward torque output above 300 to 350 lb./ft. – and traction is enhanced, you tin effigy on eventually breaking the transmission. Fifty-fifty the Muncie has its limitations, simply they are significantly higher than the Saginaw or Borg Warner.

When you lot find a used four speed, a Saginaw and Borg Warner transmission will likely be flash rusted because of the cast-iron construction. The Muncie is fabricated of aluminum, and will not be rusty looking.

Exercise you know how to tell the difference between a Saginaw, a T10, and a Muncie four-speed? The easiest manner is by knowing the construction of each unit, and the differences are obvious. If the case and side cover are made of cast fe, that would make it a Saginaw transmission. If it has a cast-iron case with an aluminum side comprehend and tail housing, that will hateful you accept found a Borg Warner. To add together a footling confusion to the mix, there were Borg-Warner Transmissions that feature aluminum cases and bandage-iron side covers. Differentiating is easy, as the Muncie has seven bolts property the side cover, and the Borg-Warner uses nine.

If the case, side comprehend, and tail housings are fabricated solely of aluminum, well my friend, that would exist a Muncie. Non only are the Saginaw and Borg Warner side cover and tail housings constructed of different materials, merely the reverse shifter arm of a Saginaw is on the side cover while the T10 is located on the tail housing.

The materials used in case structure of a Muncie/Chevy four-speed mean that if you find 1 of these gear boxes in a shed or barn, the Muncie volition probably exist polish and covered in grease and/or oil, while a Borg Warner or Saginaw transmission volition usually be coated in a light layer of rust.

Saginaw Specifics

When looking at a Saginaw transmission, the front input shaft will probable take 1 or multiple grooves cut around its diameter. These grooves are there to betoken the ratios of the gears inside the transmission.

0 grooves:       Showtime 2.84, 2nd ii.01, Third 1.34, Fourth, 1.00

1 groove:         Beginning two.54, Second 1.84, 3rd i.44, Fourth, ane.00

1 groove:         Start 2.54, Second one.84, Third one.32, 4th, i.00

2 grooves:       Kickoff 3.xi, 2nd ii.twenty, 3rd i.47, Fourth, 1.00

3 grooves:       Outset 3.l, 2nd ii.46, 3rd i.65, Fourth, 1.00

When properly identifying a Saginaw transmission, the casting numbers are a surefire manner to know for sure what y'all're looking at. These numbers can be plant on the transmission case, and the first letter in this series of numbers is going to tell you exactly which Saginaw transmission you are looking at. While it'southward obvious that the four speed volition use three shift-linkage arms and the 3 speed will accept two, if the first alphabetic character is R, then yous have found a four speed. If it starts with an S, y'all are looking at a three-speed Saginaw.

Muncie Manuals

The Muncie 4-speed transmission was heralded by many equally an "indestructible" four speed used past General Motors, and establish its way into many dissimilar auto models, backside various engine combinations between 1963 and 1974. If you lot are not certain how to distinguish between an M20, M21, or M22 Muncie, knowing what to look for tin can be catchy.

Comparison images courtesy of Hurst Shifters.

The Muncie's appearance, design, and operation did not change much during the transmission'south utilize in GM production cars. Even so, there were several design upgrades and modifications made during the total production run.

The Muncie four-speed was produced in two ratios: the wide ratio (M20) and the close-ratio (M21). That being said, there was a 2d, shut-ratio version (M22) that was developed to survive duty backside engines with a college torque output, and was known as the "Rock Crusher." This version was offered in loftier-performance big-block cars starting with the 1965 Corvette. We need to make note that the early Muncie transmissions offered betwixt 1963 and 1965 utilized a 7/8-inch countershaft in the cluster gear, and those manufactured between 1966 and 1974 used a one-inch diameter shaft.

Many enthusiasts mistakenly refer to all Muncies as Rock Crushers, and this is just not appropriate. While the M21 and M22 did have the same gear ratios, the M22 did employ a cluster gear with the gear teeth having different molar angles. The M22 was designed as a road race manual, and the straighter angle of the gear teeth produced less rut and less end-loading of the gears. This decreased helix bending of the gear non only created a stronger gear set, merely it also produced a substantial amount of gear "whine" which is highly noticeable when driving the motorcar.

The M20 and M21 used a gearset with a more angled tooth design on each gear (left). The M22 Rock Crusher used a gearset that features less of an angled-tooth gearing (right). Images courtesy chevelles.com

The gear ratio of the Chevy iv-speed transmission placed in any car was ordinarily determined by the engine size and rearend axle ratio. If a car came with an beam ratio of iii.73 (or numerically higher), it commonly came with a close-ratio transmission. Vehicles leaving the factory with an axle ratio of 3.55 and numerically lower gears, typically incorporated a broad-ratio transmission.

The casting number 3925660 denotes this as a 1968 – 1970 Muncie with a 1-inch cluster shaft.

In order to correctly identify a Muncie four-speed manual, several visual clues are needed, and those cues involve the casting numbers on the example, side cover, and tailshaft.

Primary Case Numbers

Casting Number          Year                             Notes

3831704                      1963                 7/8-inch cluster, small bearing

3839606                      1963 – 1964     7/8-inch cluster

3851325                      1964 – 1965     7/8-inch cluster

3851325                      1964 – 1965     7/eight-inch cluster

3864848                      1965                 seven/8-inch cluster

3885010                      1965 – 1967     1-inch cluster

3925660                      1968 – 1970     1-inch cluster

3925661                      1970 – 1974     one-inch cluster

Tailshaft Housing Casting Numbers

Casting            Year                                      Notes

3831731          1963                  Thin fin tailshaft, driver'due south side speedometer, 27 spline

3846429          1963                  Thin fin tailshaft, driver's side speedometer, 27 spline

3846429          1963 – 1965      Thick fin tailshaft, driver's side speedometer, 27 spline

9779246          1964 – 1965      Pontiac Catalina long tailshaft, passenger'south side                                                                   speedometer, 27 spline

3857584          1966 – 1970      Passenger'south side speedometer, 27 spline

3978764          1970 – 1974      Rider's side speedometer, 32 spline

The casting number 3857584 tells u.s.a. that this is a 1966 or 1970 Muncie tailshaft.

Side Cover Casting Numbers

Information technology is easy to decide whether you have an early or afterwards model Muncie iv-speed transmission past the fashion the transmission'due south linkage arms are attached. The 1964 through 1968 Muncie side covers had a stud coming out of the side cover that secured the linkage arm via a nut. The 1969 and after models utilize a commodities to secure the linkage to the manual.

The numbers 3831707  and the shifter linkage beingness fastened with studs and basics brand this a side cover for an early Muncie.

Casting Number                      Notes

3831707                   Early side encompass; 1963 – 1965

3884685                   Early side embrace; used with 3857584 tailshaft housing

3950306                   Belatedly side cover – no switches

3952642                   Late side cover with manual controlled spark switch

3952648                   Late side cover with transmission controlled spark switch

335308                     Late side embrace with neutral safe switch

A Quick Await

While casting numbers are a definite guideline for identification, a quick, somewhat accurate way to apace identify Muncie transmissions involves the input shafts. The Muncie utilized seven different input shafts. All transmissions with a 26-spline input shaft used a 32-spline output shaft, and all those with a 10-spline input shaft were paired with a 27-spline output shaft.

Almost all Muncie transmissions were delivered with a groove(s) on the input shaft and counter gear. These grooves were cut into the input shaft so assembly line workers at the institute could easily identify which input shaft should be installed in a particular unit of measurement.

Input Shaft Identification

Twelvemonth                Blazon    Grooves

1963-1965       M20     None

1966-1970       M20     Two

1970-1974       M20     Two

1963-1970       M21     One

1970-1974       M21     Ane

1967-1970       M22     None

1969-1974       M22     None

We said almost all Muncie transmissions had a groove(s) effectually the input shaft, and that is because most close-ratio Muncies will take one ring effectually the input shaft. But, those built betwixt 1963 and 1965 volition not have whatever rings effectually the input shaft. Starting with the 1966 models, the wide ratio versions got ii rings around the input shaft, and the M22 input shaft had no rings and looks like a 1963 through 1965 wide-ratio input shaft. Also, in that location were some input shafts produced by the aftermarket and General Motors that have no identifying rings on them. This is a large reason why some guys will non rely on transmission identification by the input shaft grooves.

So now that nosotros have given you lot some insight into identifying the Chevy four-speed manual, the next fourth dimension you are scouring the swap meets or local Craigslist ad, y'all'll have a better understanding of what you lot are looking at, and you'll get exactly what yous desire.

DOWNLOAD HERE

What Is the Best 10 Bolt Gear to Use With 1975 Super T10 in a 1970 Chevelle UPDATED

Posted by: kevinretontook.blogspot.com