Rover's Vikingship Overhaul of the LT 77 Gearbox
part three
Rover's Vikingship


This part of site is an attempt to organize and add to the web resources for the Rover SD1 to form a cohesive and easily usable guide for those of us without easy access to expert repair and/or advice. It is not offered in any way as a definitive source and we take no responsibility for any errors that may exist.
the webmaster Rene Winters.

1st Gear End-Float

To ensure the correct 1st gear end-float fit a dummy bearing. An old centre bearing bored out to be a slide fit will do; then fit the old circlip.
The end-float is the gap between the bearing and the circlip. The correct float is given in your repair operation manual.
It is corrected by replacing the 1 st gear bush, with another from the range available; then press the centre bearing onto the shaft, using a hand press and both parts of 1 8G47-3; then fit a new circlip.
Now at the front of the shaft, fit the 3rd speed gear, its synchro-cup and the 3rd/4th hub and sleeve assembly. The longer boss on the hub must face away from 3rd gear.
Fit the spacer and with the mainshaft positioned in the hand press and the rear bearing supported on both parts of 18G47-3, press on the pilot bearing.
Next the selector shaft, fit the front spool, so that when viewed from the front, with the two lugs at the top, the slot is on the right.
Fit the 3rd/4th selector fork with its arm on top of the 1 st/2nd fork.
Rest the assembly on the mainshaft and engage the fork arms with the synch ro-sleeves.

Fit the two bearing tracks to the centre plate; then lift the mainshaft and selector shaft into position, making sure the rear selector pin passes through the slot in the centre plate. Support the 3rd/4th synchro-assembly securely.
If the sleeve is separated at this stage, you will have to strip the mainshaft to refit it.
Fit the detent ball, spring and plug to retain the selector shaft then sit the layshaft in its bearing track. 81 Fit the distance piece and reverse gear and the pivot lever, pivot pin and spring clip.
At the rear of the box, press the 5th gear onto the layshaft. The grooved boss must be to the rear, otherwise subsequent removal may prove difficult.
Press the collar into position and fit a new circlip.

Now at the front of the assembly, fit the 4th speed synchro-cup and the input shaft and after checking that the selector forks, front spool, reverse operating lever and selector pin are correctly engaged fit a new gasket and carefully lower the main casing onto the centre plate. Draw it into position with four dummy bolts. Load the bolts to the correct torque.
Fit the front spool locating boss. The front and rear bosses are easily identified and cannot be fitted in the wrong locations. The front boss is the upper one in the picture.
Fit the breather tube and cover and the two front bearing tracks.

Mainshaft and Layshaft End-Floats

Next there are some end-floats to measure. You will need a clock gauge and a feeler gauge.
First the mainshaft and layshaft, fit a spacer of known size to the layshaft recess in the front cover, the smallest spacer from the range available.
Fit a new gasket and the front cover, and correctly torque the six bolts.
The mainshaft end-float is measured using the clock gauge. With the stylus resting on the input shaft, zero the gauge; then take a reading as the mainshaft is lifted. Care should be taken to prevent sideways movement of the input shaft.
The required spacer thickness is determined by subtracting the specified end-float from the gauge reading.
Now the layshaft end-float, invert the box and place a ball bearing on the layshaft. Rest the clock gauge stylus on the ball and lift 5th gear.
The required spacer thickness is determined by subtracting the specified end-float from the gauge reading and adding the result to the thickness of the spacer already fitted.
Remove the front cover and fit the selected spacers, they can be retained using petroleum jelly. Fit a new oil seal and refit the cover, taking care not to damage the seal and making sure the spacers do not slip out of position, then fit and torque load the six bolts.
Now at the rear of the box, fit the mainshaft spacer, the 5th gear and its two roller bearings.
Fit the 5th speed synchro-cup, the hub and sleeve and the rear support plate as an assembly. The long boss on the hub must face away from the gear.

5 sp Gearbox part one
part two
part four
part five
Torque Wrench Settings



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