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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 446
Registered: 4-2003
Posted on Monday, 22 November, 2004 - 04:51:   Edit PostDelete PostView Post/Check IP

Last month I overhauled the transmission of a friend's 1953 Silver Dawn over one and a half days, the work being mostly removal and refitting. I started it up afterwardy, and it worked wonderfully smoothly and leak free. I ran it 50km, adjusting the throttle linkage and generally checking it out. Joy.

Previously, shifts were very bad, and as I guessed, the idiot who rebuilt it a few years ago had used flat GM clutch plates and not the specific Rolls-Royce wavy ones.

So, my friend set of home on the 300km trip.

Suddenly, after 50km, woops: the transmission fluid came a gusher from the front pump. My friend continued for another 100km, then gave up and called the flatbed as the other drivers were honking and flashing their lights because of the smoke from burned fluid on the exhaust.

Problem solved. The transmission runs beautifully now, with no leaks. 2-3 changes are silky smooth with no bumps whatsoever.

On installing the transmission last time, we clearly popped the front pump seal from its housing. I installed the transmission myself, and left the torus cover bolts' first tightening to my assistant after putting the halves together. My assistant was a little eager while I took a sandwich. He owned up later that he had jolted the halves apart by mistake, then tightened the torus cover down on one side with the first bolt causing the seal to be dislodged slightly. After some driving distance, clearly the seal siezed on the torus cover neck and poped out.

After my three hour drive each way today, and six hours' work, I am glad to say that a new seal cured the problem. It runs like a dream now, and I gave it a 150km run to be sure. To be safe, I replaced five torus cover bolts which looked a little stressed: not cheap at $25 each.

Morals: do the torus cover yourself, and make sure that the two halves are fully home before you tighten any bolt.

Ruptured Seal:

Transmission on stand:

Under the car before fitting: