Plymouth and Chrysler-built cars Complete Owner's Handbook of Repair and Maintenance

By Hank Elfrink

This Plymouth Handbook deals mainly with the 1955 Plymouth and Dodge models but some space has been given to other Chrysler products.

Although many components and repair procedures are the same for all Chrysler-built cars there are also many differences and it is of course impossible to deal with all these various aspects in a book this size. However, we have endeavored to make the best possible selection of subjects considered to be the most important to the average owner. Also many repair procedures on the more popular older models have been included and considerable attention has been given to the repair and adjustment of older type transmissions.

The Hy-Drive and PowerFlite automatic transmissions are discussed in considerable detail, but mainly with the object of familiarizing the reader with the operation and construction of these units. It should be borne in mind that these transmissions (the PowerFlite in particular) are highly complicated and adjustments and repairs should be left only to those who possess the necessary know-how, experience and equipment to perform these delicate operations.

To a great extent the same holds true for the Power Steering units and the electrical gear (starter motor, generator voltage regulator).

Many thanks are due to the Chrysler Division, Plymouth Division, Dodge Division and De Soto Division of the Chrysler Corporation who have been kind enough to furnish extensive service information and the material upon which this handbook is based.

1955 - Hank Elfrink

• Language: English
• Publisher: Edizioni Savine
• Release date: Nov 17, 2017
• ISBN: 9788899914424

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SECTION 1 - ENGINE

IN LINE L-HEAD ENGINES—This section covers the Chrysler-built L-head in line engines. The information contained in this section is typical for these types. Specifications are given in tables which accompany this section.

SIX CYLINDER ENGINE—Fig. A1 shows a section of the 6 cylinder side valve Dodge engine. Some models of De Soto, Plymouth and Chrysler are powered with a similar engine. Fits and clearances for these engines are given in the specifications.

CYLINDERHEAD—Always use a new gasket when installing the cylinder-head. The threads of the capscrews should be coated with sealer except the three screws that lead into the intake manifold ports (to prevent sealer to be drawn into the carburetor or valves). Capscrews should be tightened in the sequence shown in fig. A2 to a torque of 35 pound-foot the first time around. Then repeat the procedure and tighten to 65-70 pound-foot. Run engine until all parts are normalized and then re-torque.

Fig. A2—Correct sequence for tightening cylinderhead bolts

OIL PAN AND GASKETS—Fig. A3 shows the oil pan with the four gaskets installed. Before installing, clean pan and pan rail of block thoroughly and use new gaskets. Gaskets are fitted into fold over slots of the oil pan to secure a better fit. Right and left side gaskets may be installed with sealing compound applied on both sides. The end gaskets should be installed so that the ends stick above the pan at least 1/8 in. This will form a better seal as gasket is compressed.

Fig. A3—Oil pan with gaskets installed

CYLINDERBLOCK—When the engine is torn down examine the cylinders for wear and scores. Small scuff marks and scratches can be removed with a hone. Rebore cylinderblock if the bores are more than .005 in. out of round or if taper is more than .020 in. A slightly scored or worn block may be honed and .005 in. oversize pistons fitted. After honing, clean cylinder walls with soap and water and a brush, then wipe dry with clean cloth. Lubricate pistons and rings before installing in the cylinderblock.

ENGINE DATA AND SPECIFICATIONS

CORE HOLE PLUGS—To remove a core hole plug (Welch plug) drive a center punch or chisel in the center of the plug and pry out. Remove rust and dirt and use sealing compound on the plug seat before installing a new plug. Install with convex side out then expand plug by flattening it with a blunt drift and hammer.

PISTONS AND PINS—Fig. A4 shows the cam-ground U slot type piston used in the Plymouth engine. The piston is also slightly tapered, the largest measurement being at the bottom of the skirt on the thrust sides. The cylinder top ridge must be removed (with a ridge reamer) before the piston and rod assembly can be taken out of the bore. For rebored blocks .005, .020, .030, .040, and .060 in. oversizes are available.

The piston pin should be a tight thumb press fit in the connecting rod at normal room temperature and a tight double thumb press fit in the piston. The piston may be heated in hot water to facilitate pin assembly. Make sure the circlips are well seated in their grooves.

Plymouth 6 piston

Fig. A4—Plymouth V8 piston

PISTON RINGS—Piston ring end gaps should be .010-.020 in. Measure gap with ring about 2 inches from the bottom of cylinder and make sure it is square in the cylinder bore. (see fig. A5 ). Fig. A6 shows the piston rings assembled on the piston. When a chrome plated upper compression ring is installed it is best to remove cylinder glaze with a hone. This will give quicker ring seating.

Fig. A5—Measuring piston ring gap in cylinder

Fig. A6—Piston rings assembled on piston

CRANKSHAFT—Fig. A7 shows the crankshaft. The radius fillets as indicated should be strictly adhered to whenever the crankshaft is being reground. A puller must be used to remove the hub and sprocket. Punch-mark No. 2 and 3 bearing caps so that they may be re-installed in the same position and location (fig. A8). The caps may break when installed the wrong way around.

When the crankshaft is fitted to the block, use new gaskets and oil seals. Lubricate the bearings before installing crankshaft. Bearing caps should be tightened to 80-85 pound foot torque. Crankshaft end thrust is taken by the rear bearing. End play should be between .003 to .007 in.

Install oil line from pump outlet to cylinder block connection and oil pump suction pipe and screen assembly. Install timing case cover back plate, timing chain and camshaft gear, timing case cover and engine front support. Make sure the seal is properly centered in the timing case cover. Install oil slinger (if so equipped), pulley, clutch cover pressure plate assembly and disc oil pan, clutch housing pan and transmission.

Fig. A7—Main bearing and connecting rod bearing fillet radii

Fig. A8—Marking No. 2 and 3 main bearing caps for correct installation

Fig. A9—Identification of main bearing journals with thicker wall bearing shells

MAIN BEARINGS—When the main bearings have to be replaced look for a stamped number on the center weight as shown in fig. A9. An M or an R followed by a number indicates that a main or connecting, rod bearing has a thicker wall bearing. For example M2 and R1 indicate that .001 in. thicker shells are used on No. 2 main bearing and No. 1 connecting rod bearing. These bearings are available in the following sizes: .001, .002, .003, .010 in., .012 in., .020 in. for mains and con rods. .030 and .040 in. inserts are available for mains only.

Main bearing clearance is usually between .001 and .0015 in. When the engine is not down a fair indication of the clearance can be obtained by the shim stock method or the plastigage method.

Note: When installing a new rear main bearing in Hy-Drive equipped engines, use a lower insert that does not have the oil drain back groove and hole in the white metal surface.

Fig.A10 shows the rear main oil seals on the 1946-52 models. If inspection indicates that the upper oil seal must be replaced, remove the flywheel.

Fig.A11 shows the rear main bearing oil seal as used from 1953 on. The upper oil seal is easily removed once the lower seal has been taken out. Push one corner until the other end protrudes after which it can be gripped with pliers and taken out. Before installing a new seal coat the contacting lip with grease. Push into place with a rolling motion.

Due to constructional changes in the 1953 model P 24 Plymouth engines the cylinder block, crankshaft, rear main bearing oil seal and cap gaskets are not interchangeable with engines built prior to 1953.

CAMSHAFT AND BEARINGS—Removal of the camshaft necessitates removal of the cylinderhead, timing case cover, camshaft sprocket, timing chain and fuel pump. If the valves are not going to be removed hold them up by inserting wooden wedges under each valve head as shown in fig. A12 Lift valve lifters with clothes pins as shown.

Fig. A10—Rear main bearing oil seal (1946-52)

Fig. A11 —Rear main bearing oil seal (1953)

Remove thrust plate bolts and rotate camshaft while pulling it out. Press off thrust plate and collar in arbor press. Camshaft end play is measured as shown in fig. A13 It should be .002-.006 in.

A special tool (C-536) is used to remove and install camshaft bearings. When installing the new bushes make sure the oil hole is in line with the passages in the block.

Fig. A12—Method of holding up valves and tappets for removal of camshaft

Fig. A13—Measuring camshaft end play on thrust plate

VALVES—The valves can be removed after the cylinderhead and the tappet cover have been taken off. Whenever the valves are serviced, also check the following parts in the valve train: valves, seats, or inserts, guides, springs, tappets, tappet bores. If the old valves and guides are being used again place them in a valve board so that they may be returned to the original positions. Remove all carbon from cylinderhead, piston tops, valves, valve ports. The valve stem clearance in the guide can be measured with a ball or plug gauge or with a dial indicator. (See fig. A14). Valves that are cracked, burned or warped should be replaced. Reconditioning of valves and seats should be done with accurate equipment. It is important that the valve guides are true and clean and the pilot should be a good snug fit in the guide. Keep seat width between 1/16-1/32 in. A valve should be discarded when less than 1/32 in. is left on the valve head margin after cleaning up on the grinder. The valves and seats should be lightly lapped together. When the lapping is completed make sure that all the compound is removed. Oil valve stem to provide initial lubrication.

Fig. A14—Measuring valve stem clearance in guide

Fig. A15—Adjusting valve clearance

EXHAUST VALVE INSERTS—Inserts that are cracked, burned or pitted should be replaced. Old inserts can be removed with a special tool (C-732). If insert is loose in the block install a .010 in. oversize insert. The counterbore should be bored .002-.004 in. smaller than the insert and the same amount deeper than the height of the insert. The inserts should be chilled in dry ice to obtain maximum contraction.

VALVE GUIDES—Replacement guides are available with undersize bores which can be reamed to fit. Stem to guide clearance limits are: .001-.003 in. intake, and .003-005. in. exhaust. The intake valve guides should be installed with the counterbored end down. The exhaust guides should be installed with the counterbored ends up. This provides better heat shielding. The guides should be driven into full depth 7/8 in. below the cylinder block top edge.

VALVE SPRINGS—Valve springs can be tested in a testing fixture. Springs that do not have 40-45 pounds tension when compressed to 1¾ inches should be replaced. Valve springs can be installed with the close-coiled end cither at the top or at the bottom. Valve springs are available in four different colors: black, green, brown and grey. The colors merely identify the manufacturer and do not refer to spring tension.

VALVE TAPPETS—Valve tappets should be adjusted as a preliminary setting to .010 in. for the intakes, and .013 in. for exhausts (adjust tappet when off the quieting ramp). When engine is warmed up adjust to .010 for both the intake and exhaust valves. Valve tappet screws are self locking See fig. A15.

REPLACEMENT—The camshaft and oil pan must be removed to replace tappets. If new tappets fit too loosely in the bores install oversize tappets. Oversize tappets are available in the following sizes: .001, .008, .030 in. If a reaming tool is to be used, remove cylinderhead, valves, springs so that pilot can be installed.

Fig. A16—Sectional view of Chrysler V8 engine

Early Type Cylinder Block (Top View)

Fig. A17—Early type engine block

Late Type Cylinder Block (Top View)