Lt77 conversion requirements

Over thinking things is one of my strong/weak points....Just looked up clutch set up in WSM - piston clearance from rest to circlip is 20mm. I think 'rest' or 'static' is throwout just in contact with fingers.
Still dont know what will indicate a spacer is needed on the slave mounting.
LT77 lever ratio is 80/118, so 20mm at push rod will produce 13.6mm at the throwout. Anybody know what the std 4 speed clutch throwout travel is ?
 
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Since I have a new Exedy clutch assenly, I contacted their chat service here. After a bit of research on the specific cover involved they said the throwout travel at the fingers should be 9mm, which provides for lifting the pressure face 1.6mm. With a P6 slave travel of 20mm, and an SD1 lever ratio of 1.45, the throwout travel would be 13.5mm. Interesting that we dont seem to see many/any reports of clutch failures on LT77 conversions..? So far my plan is to ensure that the slave travel wont bottom the lever inside the bell housing.
 
With the lt77 bolted to the block, with the clutch fitted to the flywheel, with the throwout in contact with the fingers the std SD1 pushrod protruded .394" outside the bellhousing face. The clutch slave, with the piston against the circlip, the pushrod contact in the piston is .64" in from the end of the slave. The mounting face of the slave is 1.54" from the end of the body. This means that with the std pushrod the piston will be pushed in 1.294" with the clutch engaged, fingers in contact with throwout. Pushing the piston to its maximum depth , the pushrod contact is 2.175" from the end face of the slave, so the std pushrod cannot bottom the piston. Still dont know why a 1/4" space may be required.
 
More doubts now. I bought a steel throwout bearing carrier , a TVR part Q0014A,and used it in the test above . It looks like FRC5368A on Rimmers site - Clutch Release Bearing Sleeve - V8 - FRC5368A | Rimmer Bros . I have now seen there are shorter carriers in composite material, and even adaptors to make them longer. Having been through something similar with there being 3 different lengths of pivot bolts, does anybody have any data on the correct length of this carrier for the LT77 as used in an SD1 installation please. the different lengths from the slots the fork slippers fit into, to the bearing are the worrying part. As best I can measure it while its installed, from the FRONT face of the ear of the slipper slot to the back of the bearing is very close to 20mm. this is for a non-self-centering throwout and pressure plate.
and it looks like this from mgbd
V8 HEAVY DUTY STEEL CLUTCH RELEASE CARRIER SLEEVE & BEARING
thanks
 
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I'm trying to cast my mind back to when I did my LT77 swap, and the release bearing was a short one, if my memory serves.
The plastic and steel ones are for the Land Rovers, if I understand correctly. I did my Disco 2 clutch last year and there were a plastic and aluminium sleeved bearing available to choose from at my spares guy.
 
I am a bit paranoid as last time I did this change (30 some years ago) I had a VERY heavy clutch that reduced the joy of the box some. Back then I didnt know anything about different length pivot bolts, or the different throwout sleeves. Dont want to repeat the heavy clutch ! Both the above are listed for SD1 with LT77,so should be OK, but it would be nice to have it confirmed by somebody with direct experience.
Edit:-just looked at the clutch section of the SD1 manual, and the throwout carrier LOOKS like its a short one in the two drawings that show it, but they are drawings, so I dont think thats conclusive.
Here are two carriers I have loose. The long one is 67mm top of bearing to bottom, composite, almost identical overall length to the big steel one on the box now. I think its a self-centering type - the front face is flat apart from a wear groove. the flat face turns smoothly, and can move sideways. the sides are plastic, and there are 2 bits underneath a bit like rivets. The smaller one is 48mm , cast iron. The bores are close to identical, within 1mm. The composite one has shallow ridges inside it.

zKtiDBB.jpg


This looks like the long type of carrier.
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Sorry, bit late to the party, but i missed the last bus.

having been a P6 owner (for the 2nd time) for a week, i have already sourced a 5 speed box. I have read through all the pages and am baffled by the quality of the material. Well done all.

i hope i have the right 5 speed box. Its from a TR7. i am slowly going to collect all the bits for it and then upgrade my P6. Help will be required!
 
Welcome! Tell us please if it came with acessories like the throwout lever and bearing carrier, and the length of the pivot bolt- there are 3 different sizes, and different lengths of throwout carriers. from bitter experience I recommend you get a lever with reinforcing welded on the front, over the bulge for the pivot - on one of my SD1s the pivot broke through the arm socket. They may be listed as 'R380 HD arm', as below.

Rr7k6RD.jpg
 
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