T5 5th gear upgrade
Discussion
I believe that’s what I had on mine, commonly called the fifth gear upgrade which stops fifth gate falling off its shaft.
Mine dropped out into the bottom on my box luckily not causing any damage at all!
The one of my friends T5 dropped off the shaft and minced the whole box up which was written off!
Definitely a worthwhile upgrade. From memory mine was done by John Reid/Read.
Mine dropped out into the bottom on my box luckily not causing any damage at all!
The one of my friends T5 dropped off the shaft and minced the whole box up which was written off!
Definitely a worthwhile upgrade. From memory mine was done by John Reid/Read.
Fitting Paul Cangialosi's 5th gear stabilizer is well worth doing
However, it's not that straightforward as you need to check preload by spinning the countershaft, and that can't really be done with the mainshaft in situ
Unfortunately removing the mainshaft is tricky because you need to get 5th gear off the shaft, and it is a press fit
The first time I fitted the stabilizer I didn't remove the mainshaft but still managed to get the preload about right
Subsequently I have done full rebuilds with a new 5th gear, and then I was able to follow the recommended procedure
Here you can see both boxes have the stabilizer fitted

And here you can see the 5th gear before being pressed in to place

Anytime you take the gearbox out you should check and adjust input shaft preload - without fail
Otherwise you risk this happening

Both the Countershaft and Input shaft are destroyed

The Countershaft is not a problem, they are cheap and easy to find in the US, I paid just $100 for an Indian made part

You will be very lucky indeed to find a new or used input shaft, they are TVR specific (the Cossie one is different) and just don't exist any more
However, it's not that straightforward as you need to check preload by spinning the countershaft, and that can't really be done with the mainshaft in situ
Unfortunately removing the mainshaft is tricky because you need to get 5th gear off the shaft, and it is a press fit
The first time I fitted the stabilizer I didn't remove the mainshaft but still managed to get the preload about right
Subsequently I have done full rebuilds with a new 5th gear, and then I was able to follow the recommended procedure
Here you can see both boxes have the stabilizer fitted

And here you can see the 5th gear before being pressed in to place

Anytime you take the gearbox out you should check and adjust input shaft preload - without fail
Otherwise you risk this happening

Both the Countershaft and Input shaft are destroyed

The Countershaft is not a problem, they are cheap and easy to find in the US, I paid just $100 for an Indian made part

You will be very lucky indeed to find a new or used input shaft, they are TVR specific (the Cossie one is different) and just don't exist any more
FarmyardPants said:
Get the Quaife big gear upgrade, semi straight-cut so racy sounding but sorts the problem for good. Gearboxman.com. APM did mine, sent off my old box and they recycle your old housings, looks new from underneath. Job jobbed.
I will second this except I had mine done by Grantura engineering.The shift is better than the standard gear set as well.
gruffalo said:
FarmyardPants said:
Get the Quaife big gear upgrade, semi straight-cut so racy sounding but sorts the problem for good. Gearboxman.com. APM did mine, sent off my old box and they recycle your old housings, looks new from underneath. Job jobbed.
I will second this except I had mine done by Grantura engineering.The shift is better than the standard gear set as well.
ukkid35 said:
Fitting Paul Cangialosi's 5th gear stabilizer is well worth doing
However, it's not that straightforward as you need to check preload by spinning the countershaft, and that can't really be done with the mainshaft in situ
Unfortunately removing the mainshaft is tricky because you need to get 5th gear off the shaft, and it is a press fit
The first time I fitted the stabilizer I didn't remove the mainshaft but still managed to get the preload about right
Subsequently I have done full rebuilds with a new 5th gear, and then I was able to follow the recommended procedure
You will be very lucky indeed to find a new or used input shaft, they are TVR specific (the Cossie one is different) and just don't exist any more
Was watching his video , from 8 mins onwards shows float and drag.However, it's not that straightforward as you need to check preload by spinning the countershaft, and that can't really be done with the mainshaft in situ
Unfortunately removing the mainshaft is tricky because you need to get 5th gear off the shaft, and it is a press fit
The first time I fitted the stabilizer I didn't remove the mainshaft but still managed to get the preload about right
Subsequently I have done full rebuilds with a new 5th gear, and then I was able to follow the recommended procedure
You will be very lucky indeed to find a new or used input shaft, they are TVR specific (the Cossie one is different) and just don't exist any more
.
https://youtu.be/SbD7MP_52gc
The 5th gear seems to slide off on this model , it is mandatory to remove main shaft to check 5th gear float?
If the main shaft has to come out then I'll probably use a pro.
Edited by Chimp871 on Sunday 30th June 20:21
Chimp871 said:
If the main shaft has to come out then I'll probably use a pro.
The first time I fitted the stabilizer I didn't remove the mainshaft but still managed to get the preload about rightThe reason the gearbox failed about a year later was because the circlip holding the 5th gear on the mainshaft opened up, and the 5th gear slid up the mainshaft

Once I'd taken the damaged 5th gear off and removed the mainshaft, I was then able to check the countershaft preload properly and it was fine
FarmyardPants said:
Get the Quaife big gear upgrade, semi straight-cut so racy sounding but sorts the problem for good. Gearboxman.com. APM did mine, sent off my old box and they recycle your old housings, looks new from underneath. Job jobbed.
That's good value at £1,500 for the gearset, but it probably costs double that once the gearbox build and fit is addedI think it requires a modification to the gearbox case as well (edit: I think it's the tail housing that needs modification)
I expect that will be the only option if you can't find an input shaft to replace a damaged one
Edited by ukkid35 on Thursday 4th July 08:18
I assume this is the gearboxman updated quaife gearbox? £2,400 (inc VAT) for an exchange. Pricey, but a permanent fix, yes?
https://www.gearboxman.co.uk/gearboxman-heavy-duty...
https://www.gearboxman.co.uk/gearboxman-heavy-duty...
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