S3 E-Type

Dismantling & Common Faults
The insides of the Series 3 Jaguar Gearbox

by Administrator
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Some pics & commentary on my experiences when dismantling the e manual gearbox

The Jaguar 4-speed manual gearbox is similar in most respects to other british sportscar gearboxes with some notable exceptions:

1) the case is steel-- strong but  heavy
2) reverse is helical not straight-cut
3) it has an oil pump mounted in the tail.

First job is to get the clutch release mechansm out of the way to allow access to the bell-housing bolts.
The release-arm fulcrum is a pin, secured in the arm by a roll-pin that must be driven-out first:

Then the pin can be driven down thru the casing to free the arm (there are some little cup-things that protect the end of the pin the upper one must be removed first (e.g. by drilling a small hole in it & levering it out) the bottom one will drop out as the shaft is driven out.

The release bearing is secured to the arm by some spring clips,
they hold the bearing on either side:
Next, I removed the slave cylinder itself. In my case the slave cylinder isnt looking too healthy; there's a river of brown sediment inside it...time for a reseal kit:

With the release fork out of the way, the metal tabs securing the bell-housing bolts can be bent down and the bell-housing removed:

Revealing one end of the steel gearbox casing:

At the other end, the flange must be removed from the tailshaft housing, by removing the bolt and pulling off the flange:

It can be an effort the get the bolt undone, i needed something to lever against:

Once the flange is off and the speedo drive removed, the tailshaft housing can be withdrawn....As is normal for my work on gearboxes, its only at this stage that i remember it's still full of oil.....

Removing the tailshaft housing allows the oil-pump to be seen:

Then the oil seal and tailshaft bearing can be removed. In my case there's evidence that the tailshaft bearing has been rotating in the casing as the case is scored and the bearing quite rough:

With the tailshaft housing removed, the selector housing comes off easily , revealing the gears:

At this stage everything looks nice, its not easy to tell whats going on apart from a check on end-float.
Removing the gasket material allows the end of the layshaft to be seen, this is driven forward from the back of the box allowing the gears to fall into the base of the gearbox, once the layshaft gears are out of the way the primary shaft can be withdrawn, allowing the end of the main shaft to be seen:

It's a struggle to get the mainshaft out, there isnt much clearance. The reverse lever must be unbolted and moved to the back of the casing, then the shaft plus gears are driven forwards to get the rear bearing freed from the shaft. Once the rear bearing is out of the way the shaft can just fit out the top of the casing:

Phew!   here it is on the bench:

Now the layshaft gear cluster can be seen in the bottom of the casing, as it is removed all the needle rollers will fall out:

A closer look at the layshaft reveals it is badly worn at the front (where the load is highest), this needs to be replaced:

The inside of the little oilpump looks like this:

In my case I wonder if this has been turning properly, as all the bearings fed by it appear to be in bad condition. OK, that's it for today. Next time I need to start dismantling the gears on the mainshaft.
Dismantling & Common FaultsMatt|13 Dec : 09:14

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The tailshaft housing can be very difficult to remove, I have found that using a socket that just fits over the output shaft threads, (add a washer between the socket and the output shaft) and while holding the housing give the socket a few good wacks, the housing will slide off. much better than trying to pry the housing off and risk either cracking the housing flange or scoring the case and not getting a good oil seal.

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