LT77
- Thread starter JKR100L
- Start date
Rumblin_Ron
New Member
I do believe there is an article about this in an issue of the club magazine, I'm sure P6ROC('s) do back issues ! I do remember the Auto was recomended as the transmition tunnel is bigger.
Hope this helps
Hope this helps
If you have an S already it's reasonably straight forward. The exhaust should be OK as is, maybe need to rearrange the mounting bracket. The tunnel requires a little use of a large hammer or pressing, the driveshaft gets lengthened or shortened slightly (can't remember which).
You need to use the LT77 clutch slave clyinder, but the 'S' master is fine.
The messiest part was getting the speedo drive sorted out. The LT77 speedo drive comes out darn close to the existing mounting brackets on the tunnel, and requires a right angle drive head. Mine is some type of Hillman I think. A new hole in the tunnel brings the cable inside of the car. Then you just need to get the speedo recalibrated.
Certainly makes a difference being able to cruise at 60mph with only 2300 on the clock rather than 3000...
You need to use the LT77 clutch slave clyinder, but the 'S' master is fine.
The messiest part was getting the speedo drive sorted out. The LT77 speedo drive comes out darn close to the existing mounting brackets on the tunnel, and requires a right angle drive head. Mine is some type of Hillman I think. A new hole in the tunnel brings the cable inside of the car. Then you just need to get the speedo recalibrated.
Certainly makes a difference being able to cruise at 60mph with only 2300 on the clock rather than 3000...
If its an S not an auto then I would advise that you remove the existing gearbox mounting brackets from the trans tunnel. It really is quite a tight fit and every little helps. this will also let you use the drive for the speedo by cutting a hole for the cable to com through.
I got hold of a SD1 speedo cable and took the gearbox end of it off and put it on the p6 cable, there is enough length if you re route it inder the carpet you also need the drive gear from a SD1 with a mechanical not a electronic speedo.
Dont forget that you will need an SD1 spigot bush that goes in the end of the crenck shaft (it will work with the p6 one but the gearbox bearings wont last long. and ther only a few quid from rimmer bros.)
clutch slave cylinders are the same (p6 or sd1)
the clutch part you need to change is the friction plate. (differnt splines) you can re use the p6 cover plate.
P6 auto propshaft
Give yourself plenty of time to sort out a nice gearbox mount. I didnt and it fouls on the exhaust! it should be possible to make it the exhaust fit, but you have to muck about with the front mounting bracket that used to bolt to the gearbox.
Good luck, it makes the car a lovely cruiser and much more useable if reverse and second didnt work on your old gearbox!
I got hold of a SD1 speedo cable and took the gearbox end of it off and put it on the p6 cable, there is enough length if you re route it inder the carpet you also need the drive gear from a SD1 with a mechanical not a electronic speedo.
Dont forget that you will need an SD1 spigot bush that goes in the end of the crenck shaft (it will work with the p6 one but the gearbox bearings wont last long. and ther only a few quid from rimmer bros.)
clutch slave cylinders are the same (p6 or sd1)
the clutch part you need to change is the friction plate. (differnt splines) you can re use the p6 cover plate.
P6 auto propshaft
Give yourself plenty of time to sort out a nice gearbox mount. I didnt and it fouls on the exhaust! it should be possible to make it the exhaust fit, but you have to muck about with the front mounting bracket that used to bolt to the gearbox.
Good luck, it makes the car a lovely cruiser and much more useable if reverse and second didnt work on your old gearbox!
A quick thought with this one. The commonly used term is an "LT77" box. Be wary, there are many different varieties. Besides the SD1 they were fitted to Sherpa vans, small Triumphs, XJ40 Jags and all sorts. The gear ratios vary, some are strengthened etc etc.
There is now a modern equivalent called the R380, much beloved of Morgan's etc. A good place to read up on this and potential problems with the LT77 is the RPI website (www.rpiv8.com/transmission-3.htm).
The Dutch Rover SD1 site (www.roversd1.nl/sd1web/) also has an excellent set of pages on LT77 overhaul.
Chris
There is now a modern equivalent called the R380, much beloved of Morgan's etc. A good place to read up on this and potential problems with the LT77 is the RPI website (www.rpiv8.com/transmission-3.htm).
The Dutch Rover SD1 site (www.roversd1.nl/sd1web/) also has an excellent set of pages on LT77 overhaul.
Chris