Fitting T5 gearbox to Griff
Discussion
Been considering changing the gearbox on my pre-cat 400 to the T5 as used on the Tuscan as it seems to get better reports.
Have been put off by the all the mods and welding needed to do the switch, so was interested to see this special cross-member on ebay http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am... .
It seems like a great idea to be able to fit a T5 more simply, anybody any experience of these ?
Have been put off by the all the mods and welding needed to do the switch, so was interested to see this special cross-member on ebay http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am... .
It seems like a great idea to be able to fit a T5 more simply, anybody any experience of these ?
I don't think it's as easy as just figuring out how to mount it. You need Hoover, who I'm sur has stated before its not really worth the trouble.
Why do you want to do it?
I think the only thing 'wrong' with the LT77 is you can't fast-shift with it. But get used to how it feels and it's fine. And despite the rumours to the contrary its not a weak box. Plenty of Land Rover owners will testify to that.
Why do you want to do it?
I think the only thing 'wrong' with the LT77 is you can't fast-shift with it. But get used to how it feels and it's fine. And despite the rumours to the contrary its not a weak box. Plenty of Land Rover owners will testify to that.
This has been done recently and from what i remeber the T5 went straight into where an LT77 came from with no chassis mods required. The person whos name escapes me at the moment just fitted a different end on the box which brought the gear lever into the exact correct position so no remote linkage needed, and therefore no chassis mods required. Pretty sure he got the different end from John Reid, Grantura Engineering.
The problems you will encounter will be fixing up a new speedo signal and ecu input signal. With the LT77 these inputs come from an output on the side of the box. Not so on the T5 and you will have to find these signals.
The problems you will encounter will be fixing up a new speedo signal and ecu input signal. With the LT77 these inputs come from an output on the side of the box. Not so on the T5 and you will have to find these signals.
Here you go. Have a read of this thread towards the end.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
I have fitted the Tuscan T5 Gearbox to my Griffith 400 and I can assure you its a worthwhile modification.
Its a variant of the same Gearbox used in the 500 Griffs but with the gear shift mechanism at the correct length from the bell housing, as opposed to the standard 500 T5 gearbox which has external linkage which is not suitable for earlier Griffs as it would contact an upper chassis crossmember above the bell hosing.
Then the offset gearstick bracket is used to bring the gearshift 58mm across and 10mm back to centre the gearstick as per the LT77 gear stick position.
The speedo and ECU signals are now generated from a sensor and toothed wheel bolted between the diff and prop shaft, this is the method TVR used on T5 gearbox 500 Griffs.
Its a variant of the same Gearbox used in the 500 Griffs but with the gear shift mechanism at the correct length from the bell housing, as opposed to the standard 500 T5 gearbox which has external linkage which is not suitable for earlier Griffs as it would contact an upper chassis crossmember above the bell hosing.
Then the offset gearstick bracket is used to bring the gearshift 58mm across and 10mm back to centre the gearstick as per the LT77 gear stick position.
The speedo and ECU signals are now generated from a sensor and toothed wheel bolted between the diff and prop shaft, this is the method TVR used on T5 gearbox 500 Griffs.
g8ape said:
I have fitted the Tuscan T5 Gearbox to my Griffith 400 and I can assure you its a worthwhile modification.
Its a variant of the same Gearbox used in the 500 Griffs but with the gear shift mechanism at the correct length from the bell housing, as opposed to the standard 500 T5 gearbox which has external linkage which is not suitable for earlier Griffs as it would contact an upper chassis crossmember above the bell hosing.
Then the offset gearstick bracket is used to bring the gearshift 58mm across and 10mm back to centre the gearstick as per the LT77 gear stick position.
The speedo and ECU signals are now generated from a sensor and toothed wheel bolted between the diff and prop shaft, this is the method TVR used on T5 gearbox 500 Griffs.
Thanks to everyone for all the info.Its a variant of the same Gearbox used in the 500 Griffs but with the gear shift mechanism at the correct length from the bell housing, as opposed to the standard 500 T5 gearbox which has external linkage which is not suitable for earlier Griffs as it would contact an upper chassis crossmember above the bell hosing.
Then the offset gearstick bracket is used to bring the gearshift 58mm across and 10mm back to centre the gearstick as per the LT77 gear stick position.
The speedo and ECU signals are now generated from a sensor and toothed wheel bolted between the diff and prop shaft, this is the method TVR used on T5 gearbox 500 Griffs.
g8ape : sounds good and thanks for the confirmation. TVR must have thought it worthwhile changing to the T5 for the Griff 500 and Tuscan to give improvements and I'm keen to do the upgrade. The special bolt-on cross-member (http://www.ebay.co.uk/itm/TVR-Griffith-to-Tuscan-Gearbox-Cross-Member-/221151548522?clk_rvr_id=409041859166&afsrc=1) and the idea of the offset gearstick bracket seem to remove most of the hassle.
It seems that the only grey area left is generating the speedo and ECU signals. Do you know if a kit of parts is likely to be available for these, and the offset gearstick bracket? Think I would go ahead if I knew all the parts to complete the conversion were easily sourced.
I have carried out the T5 Tuscan Gearbox conversion into my griffith earlier this year and will email you regarding the other parts required, the most complex part of the conversion was designing the Gearbox Crossmember to be a bolt on item and achieve the correct height for the engine, gearbox and resultant prop shaft as well as achieving good exhaust clearance I am very fortunate to have access to a four post lift and other garage facilities.
The speedo and ECU interface is at first quite daunting but in acctuality very straight forward with a number of speedo and speed sensor options available, Speedy Cables technical department are very helpful.
The speedo and ECU interface is at first quite daunting but in acctuality very straight forward with a number of speedo and speed sensor options available, Speedy Cables technical department are very helpful.
I'm of the other opnion on weither it is worthwhile..... but then again I got a garage to do it, and for the costs money would have been better spent elsewhere.
I do have a spare speedo that works of off electronic sensors, albeit it starts at around 7 o'clock, rather the the pre cat 1 o'clock position
I do have a spare speedo that works of off electronic sensors, albeit it starts at around 7 o'clock, rather the the pre cat 1 o'clock position
As the T5 gearbox has no provision for a road speed sensor the Griffith 500 GKN diff sensor and chopping wheel spring to mind. I know from personal experience the GKN sensor is good enough to allow the engine to run correctly as I used one for a whole summer with a programmable speedo. Unfortunately this sensor only produces a week sign wave signal that may not be powerful enough to drive the original precat speedo as well.
I bought an EMP34-1 speed sensor from speedy cables for £40 as it produces an amplified square wave signal similar to the LT77 sensor and its easier to setup because it operates with a larger air gap and has a setup led. It has a much greater chance of driving the precat speedo but you’ll have to reduce the number of teeth on the chopping wheel down to four or less as the LT77 sensor produces roughly 4 pulses per propshaft revolution. I’m sure the precat speedo wouldn’t be very accurate unless the two internal variable resisters are for calibration.
As the original precat speedos are very unreliable and expensive to repair I decided to buy a new programmable speedo from speedy cables. It’s a direct replacement, looks identical and the needle operates in the same direction. The only difference is the odometer is digital and in addition it has trip miles.
You can see my old and new speedo in this thread, (I’m the precat owner down south)
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
From my personal experiences I would recommend the speedy cables speedo and their sensor as they work together with no drivability issues. In addition it’s new reliable electronics behind an authentic face that can be calibrated very accurately and it works with a very wide range of sensors.
Should you require further information please do not hesitate to contact me.
As with all my mods I must say ‘Although this mod works for me I can’t guarantee it will work for you’.
Good Luck & Cheers
Steve Sprint
I bought an EMP34-1 speed sensor from speedy cables for £40 as it produces an amplified square wave signal similar to the LT77 sensor and its easier to setup because it operates with a larger air gap and has a setup led. It has a much greater chance of driving the precat speedo but you’ll have to reduce the number of teeth on the chopping wheel down to four or less as the LT77 sensor produces roughly 4 pulses per propshaft revolution. I’m sure the precat speedo wouldn’t be very accurate unless the two internal variable resisters are for calibration.
As the original precat speedos are very unreliable and expensive to repair I decided to buy a new programmable speedo from speedy cables. It’s a direct replacement, looks identical and the needle operates in the same direction. The only difference is the odometer is digital and in addition it has trip miles.
You can see my old and new speedo in this thread, (I’m the precat owner down south)
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
From my personal experiences I would recommend the speedy cables speedo and their sensor as they work together with no drivability issues. In addition it’s new reliable electronics behind an authentic face that can be calibrated very accurately and it works with a very wide range of sensors.
Should you require further information please do not hesitate to contact me.
As with all my mods I must say ‘Although this mod works for me I can’t guarantee it will work for you’.
Good Luck & Cheers
Steve Sprint
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