It was purchased a family car, as well as a dally driver to and from work. It rolled off the line from the factory with a turquoise vinyl Interior, bucket seats, a center console, head rests, as well as air conditioning and other accessories. Many stories have been told from the adventures endeavored from behind the driver’s seat of the car. Now however, its two tone Cameo White body, and Glade green hardtop remain to be covered In dirt and paw prints. The cutlass’ heartbeat is a 250 horsepower “Rocket” 350 VI Chevrolet small block tutor, producing 355 lbs. F torque at 2600 Revolutions per Minute (RPM), with a compression ratio of 9:1 (Oldsmobile Informational). It is naturally aspirated with a two barrel carburetor and Is coupled with the optional Hydra-Metal 3-speed turbo 350 transmission, together producing a 10:8 horsepower to weight ratio (Horsham). From there, the power is transferred to the rear axle. This axle is a four-link live axle type, with 3. 23:1 gears installed. This gear ratio was the “all-round” preferred set to meet somewhere In the middle of top economy and maximum performance (Oldsmobile Informational).
With all that “GO,” this car weighing in at 3650 lbs, (while full of gals needs lots of “WHOA. ” It has drum brakes with self-adjusting dual master cylinders, and 9. 5″ cast-alloy drums installed on all four corners to bring everything to a stop. The body Is Just shy of 202″ In length, 76″ wide, and is mounted on a 112″ wheel base chassis (Oldsmobile Cutlass). It Is composed of K-braced front cross members and frame torque boxes, which allow for a lower body floor. The rear axle is Informational). This features large coil springs and double-action shock absorbers. The front suspension carries 56. Of the overall car weight (Oldsmobile Cutlass), and is a double wishbone (A frame) design with coil springs and dual action shocks as was for the rear axle. Perhaps one of the most common and well known automatic transmission ever produced was General Motors’ Turbo 350. The Turbo 350 is a fully automatic transmission made up of a 3-element hydraulic torque converter and two planetary gear sets. The planetary gear sets are used in conjunction with four multiple-disc clutches, two roller clutches, and an intermediate overrun band to obtain proper fiction elements necessary (350 Turbo).
Weighing in at 120 lbs. ND being 21 – %” long (Novak), this cast aluminum transmission is much larger than the manual style it replaced and was left unpainted. It is easily distinguishable by its oil pan which is chamfered on the rear passenger side corner, and its integral bell housing. It holds 5 quarts of automatic transmission fluid. They are also identified by the transmission model and code numbers stamped on the side of the servo. This identification will include a prefix code letter(s), followed by a 5, the year of production, and the serial number of the transmission itself (Former).
The transmission itself offers three driving SE selections labeled “D,” “S,” and “L. ” Normal driving is achieved by selecting the “S” range. This allows the car to start in first, shift to second and third. As speed decreases, it will automatically shift back down and provide small engine braking. In the “L” range, the transmission is not allowed to shift into any gear except 1st. This is designed to receive the most power for pulling or for steep inclines and heavy engine braking. The last selection is “D,” named for the forced detent downshifts.
In this range, the transmission can be downshifted from fourth to third and third to second within a select speed range. Reverse is equally as important and is achieved through the use of a friction clutch through adequate oil pressure. This friction clutch is unable to engage after a speed of MPH in the forward motion by a blocker piston to prevent accidentally selecting reverse will moving forward. By putting the transmission in park, the output shaft is locked to the transmission case via a parking pawl that grabs lugs on the backside of the reverse planet carrier.
A detent prevents accidental movement into park while still moving in either direction (Former). The power flow in the transmission begins with the torque converter. It uses oil to hydraulically multiply torque when needed. It consists of three major elements, the converter pump, the turbine, and the stator. As the engine turns, it powers the pump, which works as a centrifugal style (much like a water pump) and flings hydraulic oil away from the center. As the oil begins to flow, it pushes on the turbine blades, the turbine is connected to the transmission, which then begins to have torque applied to it and spin as well.
The fluid is then forced to change direction by the stator, which directs the fluid from the turbine back to the pump. This increases the efficiency of he torque converter greatly. See Figure 1 . Figure 1 From the torque converter, the power is transferred to two gear sets in the transmission. Each gear set is made up of six major components, the sun gear (the main internal gear), four planetary gears, and an outside ring gear. Each one of these components can either be driven by the engine, or locked in place by a band clutch. Possibilities is what makes it possible for the transmission to shift.
It is also equipped with one overrunning clutch. This is a one-way roller that allows engine braking to occur in first, second, and third gear. It achieves this by allowing the input shaft to spin faster, but never slower than the output shaft. Each of these actions are controlled by many different parts and materials working together. To begin is the valve body. This is the brain of the transmission, and ironically represents the looks of one. It is filled with many passages for oil to flow, each controlled by individual valves. These valves may be controlled by many things, including the governor or manual linkages.
The governor is attached to the output shaft of the transmission and senses the speed of the vehicle. As the speed increases, the governor weights egging to fly out, much like the governor setup of older tractor engines. As the weights fly out, the governor allows more oil to flow, as well as higher pressure. As certain pressures are reached, the valves in the valve body release, performing a function, such as releasing or contracting a band brake. See Figure 2. To begin in neutral, all clutches and overrun bands are released, allowing no power transfer from the torque converter to the output shaft.
Oil flows from the pump to the regulator valve. When this pressure exceeds necessary line pressure, the excess is diverted to fill the converter. If the transmission is put into drive, or first gear, this engages the forward clutch set. It also locks the intermediate overrun roller clutch. The front gear set receives clockwise power to the ring gear, while transmitting power via the sun gear to the rear unity, producing a converter torque ratio of approximately 2:25 at stall. The rear set receives power via the sun gear, and while the planetary gears are held, transmits the power to the ring gear.
This produces The manual linkage directs line pressure to the Reverse, Neutral, and Drive ports, 2-3 shift line pressure is also increased to cushion when the next shift takes lace. The rear roller clutch freewheels in first gear and oil is directed to the gear set and is regulated by governor pressure. This pressure increases with vehicle speed, and acts as a cushion for the 1-2 shift valves. When the governor pressure reaches 46 Pounds per Square Inch (AS’), the oil pressure over powers the 1-2 valve spring which opens the valve.
This shifts the transmission by directing drive oil to apply the intermediate clutch. The front gear set continues to receive power at the outer ring gear, however the inner sun gear is held, and the planetary gears provide the output power. This reduction ratio is approximately 1. 52 to 1. Everything else remains the same. This shift into second gear will happen between 42-49 MPH at full throttle, or 9-12 MPH at minimum throttle. As governor pressure continues to increase yet again, the 2-3 shift valve begins to become overpowered by the oil pressure.
Once 77 SSI is reached, the direct clutch is engaged by the new oil, this shift is cushioned by the Reverse, Neutral, Drive oil pressure on the other side of the piston. At this point, the intermediate, direct, and forward clutch are now all engaged at once, and the overrun roller clutch is allowed to freewheel. Power is distributed to the front gear set through the sun gear drive shell and turn with a ratio of 1 . This shift into third gear typically happens between 70-79 MPH at full throttle, or approximately 20 MPH at minimum throttle.
When reverse is engaged, the forward clutch is disengaged, the direct clutch and low/reverse clutches are both engaged, and the intermediate roller allows oil pressure to enter the reverse valve circuit. Oil flows to the outer area of the direct clutch piston, to the outer area of the low and reverse clutch piston, and to both the 1-2 and 2-3 shift valves. It also acts on the reverse boost valve to increase line pressure to a maximum of 250 SSI at stall. This allows the vehicle to move in reverse by applying torque to the front gear sun gear drive shell and the sun gear.
The reverse clutch is applied, which then prevents the carrier from turning. This reverses the rotation of the ring gear, causing reverse and a 1. 93:1 ratio. Much like manual transmissions, these turbo 350 transmissions are equipped with detente to hold each shift in place. Instead of the typical ball and spring, these detente act as valves to hold oil pressure on the downshift valves. These detente are activated by the downshift cable. Each of these valves (manual control, shift, and detent), each act as a piston in a valve-less 2 stroke engine.
As they move forward or back, they slowly open or close ports (or valves) for oil flow. See Figure 3. One of the only ways to check all of these functions in the transmission is to run a pressure test. With the brakes applied and the engine running at 1000 RPM, the SSI should be between 60-90 when in drive, between 85-150 SSI while in reverse, and between 55-70 SSI while in neutral. While in drive and the engine at idle, operating SSI should rest between 60 and 85 AS’. Other issues may be caused by worn clutches, bands, or shims. Correct input shaft end play should be between 0. 033″ and . 064. Correcting this end play is done by adding or removing thrust washers located between the main oil pump and the direct clutch drum. Three thicknesses of pressure plates are used within the transmission. These are . 245″-. 255″, . 275″-. 285″, and . 305″-. 315″. A clearance of 0. 010″- 0. 080″ should be obtained between the top faced plate and pressure plate. Each internal shaft is supported by bronze bushings. Each should be installed 0. 010″ above flush (350 Turbo). After the power has exited the transmission through the output shaft, it has to transfer the torque to the axle, via a drive shaft.
The drive shaft on the 1969 Oldsmobile Cutlass begins with a universal slip yoke that slides onto the output shaft of the transmission. This also doubles as a seal for the transmission tail housing and is installed with one once of lubrication and provided with a small vent hole on the back side of the slip yoke. The shaft itself is made of steel, and welded to cast iron yokes. The rear yoke is unique in the fact that it actually consists of a coupling yoke and two set of ball stud yokes. Each half of the yoke takes one half of the angle pitch.
Whenever removing these ball stud Joints, be sure to reference disassembly of the connecting yoke and both flanges to retain proper shaft balance. Each set of universal Joints have 25 roller bearings per cap, and have external retaining rings which hold them in place on the internal side of the yoke. The coupling yoke has two sets of ball yokes for the C. V. Joint. These are also held by retainer clips. Once the propeller shaft is installed in the car, it must meet runabout specifications. Being measured at 5″ from the front weld, in the center of the shaft, and at 2″ from the rear led, the shaft must be equal to or less than 0. 24″ of runabout. Flange runabout must not exceed 0. 008″ Transmission angle should be set at % degrees, and shims should be added or removed to obtain proper setting. Differential nose angle should be set at 10 % degrees, and is corrected by adding or removing shims at the axle. CAUTION: The four point live axle is driven from the propeller type drive shaft. This axle allows the engine torque to be transmitted into a perpendicular direction. This Cutlass is equipped with A 10 bolt differential (referring to the number of bolts in the differential cover) and 3. 3:1 gears.
It is easily spotted by the ribs on the side of the housing and is commonly known as a “P” style rear axle. The pinion gear stem is 1. 625″ in diameter and uses 30 spines to connect to the yoke of the drive shaft and drives an 8. 5″ ring gear. The ring gear itself has 42 teeth, and the pinion has 13 in total (Former). Each axle is machined with 28 spines and use two sealed ball bearings on the end of the axle with an oil seal located inside the axle tube behind the sealed bearings. They have a bolt-in design and do not use c-clips to stay in place (Rolling).
The rear axle has a removable carrier. The pinion is mounted by two tapered roller bearings that are preloaded by a collapsible spacer. The pinion depth is set using a shim between the pinion head and the rear pinion bearing. Two tapered roller bearings also support the differential itself. These are preloaded and the differential backlash is set using two threaded sleeves between the bearings and pedestals. This preloaded should be set using inch pounds, and should be 8-12 in/lbs. Using used bearings, or 24-32 in/lbs. Using new ones.
The side gears and pinions mounted in the differential are held in place by a lock screw and are backed with thrust washers. Backlash for the pinion to ring gear must be set between 0. 005-0. 009″, and variation over the entire ring gear backlash must not exceed 0. 002″. Pinion depth is achieved using cast iron production shims and vary from 0. 210-0. 272″ in increments of 0. 002″. Pinions depth will be marked on the pinion gear face. Once proper depth is achieved, the front pinion nut should have been marked before disassembly, then tightened to 1/16″ past the mark made before.
The axles should be bolted into place and have no more than 0. 020″ end play. If more end play is present, the sealed roller bearings should be replaced. The differential should be filled to within 3/8″ of the filler hole, or roughly around 4 h Pits. Of S. A. E. 90 GAL.-5 Gear lubricant. Parts for this Cutlass are very readily available as it is a fairly common terrain as well as one that is fairly new as well. Many local parts stores such as Scarcest, Nap, or Advance Auto Parts would carry much of what any restoration would ask for.
For those hard to find parts, many salvage yards such as CT Auto Ranch out of Denton TX has many salvaged cutlass’ in stock and parts ready to ship. Other resources may include magazines and blobs such as Hemming Motor News, or Olds Club of America. Naturally, many internet sources exist as well such as Rocket. Com, Illiterateness. Com, Summit Racing, or even Pops. Com. Anything related to the transmission can be found quite easily as it is one of the most common transmissions out there. The detersives yoke however, may be a different story as it is a strange set up with the double rear yoke.
If one is not available at a salvage yard, there are many companies around who make custom drive shafts such as Anta’s, or Dyne’s Detersives companies. Technical information is also available quite easily and quickly for this car and Just about anything on it. To start is the Olds Club of America. This club is dedicated to Oldsmobile only and has connections to people who have the answers, they have classified ads, and even Judging guidelines. Another very good source for information MI, the center has many original service manuals, brochures, and catalogues available in person, or on their website.
Any original manual is a great place to start. The “Motor’s Automatic Transmission Manual” is a 740 page volume that includes 240 pages of oil circuit diagrams of which the majority are in color. This book is mentioned in one of my sources. Original pamphlets or brochures are a great source or technical information or selling points of these cars and their components. If all else fails, many blobs and posts are out there on car geek sites to help those tech savvy restorers out there to find the information they need. The research of this paper really taught me a lot.
The Olds Cutlass used to be Just a car parked in the back of the shed, and as I grew older it slowly began to mean more and more to me, however I have never taken the time to really look into it. It’s one of those things that you see or walk by every day, but never step back and actually look at it. This paper gave me a new perspective on an old car, my father’s old car. I was shocked with how much information is out there for the Cutlass, and not Just any cutlass, for whichever make or model you may have. Information, brochures, pictures, and clubs are fairly abundant for the Oldsmobile, which is something that I am definitely not used to.
Naturally, I learned a lot about the car, all the options available, trim packages, and where to find this kind of information. I also learned a lot about automatic transmissions, which is something I have never looked at in depth before. It took a while to get my head wrapped around it all, but it makes sense now that it has had the time to sink in. It is amazing how much can go into such a small item, let alone an entire car. The amount of specifications, dimensions, tolerances, and other information is absolutely endless. At least for a car of this era.