Perform the shop work required to do this installation using good shop safety and workmanship practices. Reference to a quality Sprite/Midget service manual will be required.
Purchase a five speed transmission from a 1979- 1982 Datsun 210. These can be confirmed as correct by both the input and the output shafts being 13/16", 18 spline. With the transmission get: gearshift lever, throw out bearing carrier and fork; and for exchange purposes get the output yoke (driveshaft front yoke). If the car is to be used on the street, obtain the stock Datsun 210 speedometer cable and housing. Also purchase: #3064 C.R. Throw out bearing (fits R.W.D. Toyota Corolla, Celica, etc.); #37498 United (NAPA) Slave Cylinder (fits 1980 - 1986 Nissan 2 W. D. pickup); #38117 United (NAPA) Slave Cylinder Hose (fits 1980 - 1986 Nissan R.W. pickup). It is suggested that a new transmission rear oil seal be installed. Use 11615 CR (a 30x45x10 metric seal).
PREPARATION OF CAR
Remove engine, transmission and driveshaft. Underneath the heater, in the area over the bellhousing, the heater duct built into the body will need to be dented upward slightly to give extra clearance for installing the engine/ transmission assembly. Many are found to already be dented here to ease installation of the stock units.
If you are unwilling to put a dent in the heater duct, the engine can be installed without this with some effort. Use the option seal listed above in the rear of the transmission. This gives some extra installation room. If the engine has a vibration damper on the front pulley it may have to be removed, reinstalling it after the engine has been lowered into place.
INSTALL ADAPTER ON ENGINE
The adapter bolts on behind the original rear engine plate, approximately 5/16" thick, fitted to later model cars. If the thin rear plate, about 1/8" thick, furnished on early engines is used, the rolled edge must be ground off flush with the rear of the plate.
Remove flywheel. Remove only the bolts in the rear engine plate that will be replaced by the adapter plate bolts. Try not to break the gasket seal between the plate and the engine block. If broken, it should be replaced. Install the adapter with the countersunk head screws furnished. Use the nuts, lock washers and flat washers on the bottom two bolts.
Reinstall the starter, using the 3/8" x 1 ¼" NC cap screws and lock washers furnished for this purpose.
Remove the pilot bushing and install the special bushing furnished, driving it in up to the shoulder. Very late engines will require the 3/4" O.D. bushing. Lube the bushing. Reinstall flywheel.
Install and align the clutch disc furnished using the stock pressure plate.
Carefully measure the distance from the rear surface of the clutch throw out bearing contact pad on the clutch pressure plate to the back side of the adapter plate. Use a straight edge across the clutch pressure plate. If the clutch cover holds the straight edge off the contact pad, measure this distance and subtract it from the distance from the straight edge to the back of the adapter. Note this Pad-to-Adapter figure for use later.
PREPARE THE TRANSMISSION
Cut clearance for starter drive in bellhousing as follows: Before cutting, compare the transmission front to the engine rear to confirm where to cut. ( See photo #1 and #2). Looking at the front surface of the bellhousing, measure downward along the flange 4-1/8" from the bottom edge of the 1" hole in the flange and mark. From this mark, measure straight back onto the side of the transmission 3" and mark. Centered on this mark, drill a 2" hole using a hole saw. Saw from each edge of this hole forward to the transmission front flange, making a "U" shaped slot to clear the starter drive.
The two bottom bolt holes in the Datsun transmission are threaded holes. Drill through these holes with an 11/32" bit to make clearance for the 5/16" bolts that will be installed later. A rib on the bottom of the transmission will interfere with the bolts to be installed here. File or grind the rib to make clearance for these bolts.
Remove the gearshift lever. Check the pivot bushing for the lever. Most are found bad. A new bushing is Nissan part # 3285H1010. Installation of a new transmission rear housing seal is suggested. Part #11615 CR is less expensive than the original seal because it doesn't have the protective shield, unneeded inside the Spridget transmission tunnel.
Along the back top slope of the transmission bellhousing area will be found a protrusion. Grind or cut this off to ease installation of the engine/ transmission assembly.
Remove the throw out bearing and carrier and release forks. Use a tubing cutter to cut 3/10" off the front end of the tube the bearing carrier sides upon. (See photo #3).
Install the N-3064 throw out bearing on the original carrier. Assemble the release forks, throw out bearing carrier and spring into the transmission. With the throw out bearing pushed fully to the rear, measure the distance from a straight edge across the front edge of the bellhousing to the front face of the throw out bearing. (See photo #4). This distance must exceed the Pad-to-Adapter distance measured earlier by 1/16" to 3/32" to allow for clutch wear. If it isn t this much, grind the rear of the clutch forks where they contact the front cover of the transmission when the fork is in the fully released position. Grind small amounts, and trial fit until the clearance (as calculated above) equals at least 1/16".
Locate the back-up light switch on the right side of the transmission just forward of the mount. Remove the switch and saw the end off leaving only 1/8" or less of the hex section. Clean and fill the center hole with silicone seal and reinstall. Reverse lights will not be operational.
Look closely at how the rear mount in the kit is assembled (washer positions, etc.) Be sure final assembly matches this.
Remove the top plate of the transmission rear mount and fasten it to the transmission with the countersunk screws furnished. The "U" shaped cut out mounts to the front. Reassemble the mount leaving the bolts through the pad mounts slightly loose for now.
Bolt the transmission to the adapter plate on the rear of the engine. Use (5) 5/16" x 2 ¼" cap screws with lock washers at the top. At the bottom use (2) 5/16" x 1 ½" cap screws with lock washers and flat washers. If an exhaust pipe brace or a ground strap are attached by these bolts, the flat washers should be omitted. A rib on the transmission may interfere with the heads of these bottom two bolts. If so, grind notches in the ribs for clearance. Threads in the bottom two bolt holes in the transmission may need to have the threads drilled out for bolt clearance.
Next, install the slave cylinder, part # 37498 United.
First hold the cylinder in position noting where it contacts the front edge of the bellhousing. Grind this edge down so that the cylinder will just touch the edge when bolted in place with the spacer furnished. Install the cylinder, with the pushrod, spacer and screws furnished.
Install the furnished yoke on the front of the Spridget driveshaft. A new "U" joint is suggested.
If the Spridget is a street car, use the Datsun and the Spridget speedometer cable and housing. Remove the connector from the top (speedometer) end of the Datsun and the Spridget cable housings. To reform the Spridget connector so that it will slide over the housing, carefully drive a round tapered punch into it from the housing end. Install the connector from the Spridget onto the top of the Datsun housing. With the bottom of the housing tightened into place on the transmission the cable should extend 5/8" beyond the end of the top connector. If not, remove the connector and shorten the housing to get the 5/8". Crimp the connector into place. If you aren t certain your crimp is durable you may wish to reinforce it with a wrap of duct tape overlapping the connector and the end of the housing.
Although the speedometer cable housing can be attached to the transmission working through the gearshift lever hole after the engine is installed, it is easier to use the following: Attach the cable and housing to the transmission before installing in chassis. Form a loop extending about 8" to the rear of the transmission. Tape this loop to the rear seal area of the transmission to hold it in place during engine/ transmission installation. Remove the tape after installation.
After attaching the cable to the speedometer assure that the loop of cable in the driveshaft housing is far enough back to prevent the cable from contacting the exhaust at its front end. Fasten the cable into place to the body to the left of the transmission.
Should the speedometer fail to operate, disconnect the cable and housing from the speedometer. Apply a coating of brazing (or solder) to the squared end of the speedometer chain, extending back about 1/4" from the tip. Grind or file this added material into a square shape approximately .124" across. Reinstall onto speedometer.
As an alternative, Rivergate Restoration Products offers a new custon speedometer cable and a ninety degree speedometer ration adapter, that both connects the speedometer more easily, and corrects the speedometer reading for the size tires and differential ration used.
INSTALLATION IN CHASSIS
Install the engine/transmission into the chassis. Loosely install the front engine mounts. Install the original bolts up through the crossmember into the rear transmission mount and tighten. Next tighten the front engine mounts. Now center the transmission in the rear mount and tighten the transmission pad mounts. Install the furnished bolts in the sides of the rear mounts from inside the car with the self-locking nuts inside the tunnel. Tape the nuts in the wrench to make starting the threads easier. Be certain the end of the right side bolt has at least 3/16" clearance to the transmission case. If not, add washers under the head.
Install the driveshaft with the furnished front yoke fitted. Grease the splines and seal surface of the yoke before installing If you expect to turn the driveshaft at very high revolutions, you may wish to have the driveshaft assembly balanced. (Kits have been installed in race cars with engine/differential ratio combinations allowing driveshaft speeds of over 10,000 RPM!)
It is suggested that the gearshift lever be shortened to a length of 7-1/2" above the pivot hole to provide a short, crisp shift pattern. Stock length may suit some. After sawing it off, grind the top end down to a diameter of 5/16" for a length of 1". Thread it 5/16" NC and the original type knob or the Datsun knob will fit.
Fill the transmission with gear lube. Valvoline Synthetic gearlube is strongly suggested for excellent shifting feel
PLUMBING CLUTCH HYDRAULICS
Use a United # 38117 (NAPA) clutch slave hose or equivalent. Reroute the original hydraulic tube to the left of the engine and shorten as needed. Install the tube nut furnished and reflare the tube (single flare is OK). Parts are included in kit to connect to a 3/16" or ¼" tube as Spridgets were equipped with either. Fasten steel tubing to the frame and keep it away from exhaust piping.
Bleed the clutch hydraulics. To eliminate all air the slave cylinder piston must be held in the fully retracted position while bleeding. Do this by running out the adjustable pushrod until it is pushing firmly on the clutch forks. Keep the master cylinder reservoir topped up while slowly and gently pumping the clutch slave cylinder into operating position.
Adjust pushrod length to give some free travel at the clutch pedal. Assure clutch is releasing fully while the vehicle is still up on jack stands.
Occasionally, after installation, it is discovered that the clutch release bearing return spring in the Datsun transmission is too weak (due to age or rust) to fully retract the new slave cylinder. This allows the clutch plate to travel past the normal release point as evidenced by clutch drag when the pedal is fully down but full clutch release with partial pedal travel. If you wish to cure this without pulling the engine, notify Rivergate Restoration Products. We will send you a simple-to-install pedal stop that will cure the over-release travel. It will be furnished at no charge.
Install gearshift boot and liner being certain it doesn't put pressure on the gearshift lever in any position. It may be impossible to prevent the early Sprite metal shifter cover from interfering with the shit lever. If so, use of the later model shift boot is suggested.
You are now ready to road test the installation. Note that clutch pedal pressure will be somewhat heavier and quicker acting than a stock Spridget. If speedometer is used, check it for correct reading, If it needs correction, different speedometer driven gears are available from Nissan. This gear is on the end of the adapter where the cable and housing attaches to the transmission. A gear with more teeth will cause the speedometer to read slower. A differential ratio change will also change the speedometer reading. You may wish to install a lower ratio (higher number) differential to increase performance and take full advantage of the overdrive in the five speed transmission. The 4:22:1 ratio seems to be preferred by most and is readily available from suppliers of used Spridget parts.
Pack the transmission output yoke (driveshaft front yoke) from both the Spridget and the Datsun 210 and ship parcel post to: Mini Mania, 31 Winsor St., Milpitas, Ca. 95035