Lt77 conversion requirements

I haven't got around to extracting the speedo cable from the instrument panel and measuring six turns of a road wheel yet, which is what Speedy Cables ask you to do in order for them to recalibrate your unit.

SpeedyCables-CalibrationForm.jpg
 
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Tor said:
Ok thanks Colin. That does sound a bit finicky, so I’ll take the drive off my spare P6 speedo and get it recalibrated by the mentioned outfit. I take it they’ve done them enough not to need specific details. Of which I have not many!
Tor
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Hi, Yes it does sound fiddly doesn't it, If doing it again nowadays I would just get it re-calibrated but at the time I had the relevant items knocking about and I was doing it on less of a budget.:rolleyes:

Colin
 
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cobraboy said:
The auto prop I used was also at full stretch and the spline was wobbly, so I fitted a 25mm Britpart prop spacer from a Land rover and closed up the prop which made the spline joint a lot tighter.
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I have been considering getting a flexible coupling or having one made up, given the amount of stretch available in the auto prop, to counteract clonking and play in the diff. Having owned and driven various cars with 'Hardy couplings' in the past I am accustomed to the feel in a cruiser-type car as opposed to something more sporting that wants everything to be sharp and direct.

I have to say, this thread is helping me a lot. I currently have drive line vibration issues with my four-speed, most evident when accelerating from 50 mph, which I think is down to my overlooking the prop alignment arrows when I overhauled the rear end, and the slightly smaller (+/- 10mm) upper diff mounts that may have raised the rear of the diff and upset the flange angle in relation to that of the gearbox output.
 

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Drive line vibration is also caused by notchy or partially seized universal joints in either propshaft or driveshaft joints, or of course play in those joints.
 
mrtask said:
I haven't got around to extracting the speedo cable from the instrument panel and measuring six turns of a road wheel yet, which is what Speedy Cables ask you to do in order for them to recalibrate your unit.
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They replied:
"You will need to send the speedometer to us along with the completed calibration details.
The cost for this service would be £110 plus carriage (we are unable to quote for carriage prior to shipping)
Please send it to us with your full instructions/completed calibration details."
 
Hi Tor,
I got my speedo calibrated by Speedy cables (the name is a bit misleading). I did the checks and filled out their form. When I got it back and installed it is reading spot on, very pleased with the job even though it took longer than I hoped for.
 
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Barten said:
I got my speedo calibrated by Speedy cables (the name is a bit misleading).
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I had mine done years ago, (while they were still in London) and like you it took a while, but if you give them a reminder they will say with a smile that the name of the company is "Speedy Cables", not "Speedy Instruments". :LOL:
 
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cobraboy said:
Which ever way you serve it up they ain't quick.
An alternative is Speedograph Richfield, specialist automotive accessory manufacturers for all your classic car needs
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I got a quote for £55 for calibration plus £13 for a P6/SD1 cable and maybe £20 shipping from these guys today, having spotted them in a different thread. Half the price, and perhaps even half the time spent, sounds like a winning proposition. They’re also willing to calibrate by percentage (20 pct), since I’d prefer to have everything ready to go in in one go.
 
I have a pic (printed only) I am pretty sure came from this site, but it isnt on this thread. Its a view of the rear of an LT77 on the bench with a modified rear mount bolted up, with 4 bolt holes in the flat side plates (that are not original). Can anybody who knows this pic please assist with a plan view or measurements that might enable me to recreate (or get close) before I get to installation? Its got photobucket overlay on it.
thanks
 
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Can anyone shed light on a good/surefire way to ensure I don't get a heavier clutch pedal with the LT77 conversion? I can add that I've got an uprated clutch kit from Clutchfix LTD that will be 10-15 pct heavier than stock, and from what I understand, using the P6 slave will make the pedal harder already?
 
Tor said:
Can anyone shed light on a good/surefire way to ensure I don't get a heavier clutch pedal with the LT77 conversion? I can add that I've got an uprated clutch kit from Clutchfix LTD that will be 10-15 pct heavier than stock, and from what I understand, using the P6 slave will make the pedal harder already?
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When I converted mine I used SD1 pressure plate, centre plate and slave cylinder and I never found the clutch to be any heavier than when it had the 4 speed.
 
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Would that count on my four-pot conversion? At least the SD1 slave as l assume the clutch assembly is smaller? Though there was the Sd1 2000 of course.
 
harveyp6 said:
Your 4 pot conversion doesn't have a slave cylinder. I can't see it having a heavy pedal action if the pressure plate isn't seized. As you say it shouldn't be any different to a normal 4 pot.
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By which I mean the same cylinder cylinder which isn't interchangable.
 
Elucidate please, l'm slightly confused. :hmm: ;)

So which clutch assembly will l be using? As l have a couple of P6 clutches on the shelf l assume it won't be them. :rolleyes:
 
It will have to be a centre plate from one of the lower capacity SD1 engines, and hopefully the matching SD1 pressure plate will fit your flywheel, if not the p6 pressure plate if it's the same diameter as the SD1 one.
If the pedal action is heavy ISTR there are two diameters of P6 slave cylinder, so if you have the small one, change it for the larger one and that will lessen the effort required at the expense of extending the pedal travel.

Didn't it come with a clutch pressure and centre plates?
 
No, no clutch assembly.

So the large P6 slave will be the one to go for then. ISTR that Original Bruiser's clutch was a mite heavy to use & l had planned on getting the larger cylinder as well as fitting the PAS.
I think l have both types of P6 pressure plate. The individual springs type & the pointy plate spring type. And l think you'll find that's what they're actually called.
 
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