Cerbera T5 gearbox - replacement /fix options?
Discussion
So... 3rd and 4th gear are no longer working on my 4.2 Cerb’ (1997, 48k miles). 1st and 2nd have become difficult to enagage too. Ironically, 5th is absolutely fine (given that’s normally the weak link).
Any suggestions on best options?
Currently thinking swopping the ‘box out for an exchange unit but undecided on which one. Replacing internals seems to take the price close to a new unit but without any warranty / assurance it’ll all work when put back together.
Previous posts point to the Gearbox Man for upgraded T5 units with shorter and improved ratios for £2k but there’s also reconditioned T5 units from TVR parts for £1k. Replacement internals are c.£350 but with labour to fit (sadly I’m not that mechanically skilled!)
Labour to do the whole box out/back job... I’m hearing 10hours but that seems quite a lot.
Option 1 - http://www.gearboxman.co.uk/psgearboxes.html
Option 2 - https://tvr-parts.com/tvr-parts/part-details/tvr-f...
The cars currently with my TVR specialists in Surrey but I’ve also been recommended to consider Python Racing.
Any help much appreciated!
Cheers
(The cars had engine, suspension and alarm refreshed in the last 18months so was hoping for nothing else major for a while but hey ho, it’s a Cerb’ and I still love her).
Any suggestions on best options?
Currently thinking swopping the ‘box out for an exchange unit but undecided on which one. Replacing internals seems to take the price close to a new unit but without any warranty / assurance it’ll all work when put back together.
Previous posts point to the Gearbox Man for upgraded T5 units with shorter and improved ratios for £2k but there’s also reconditioned T5 units from TVR parts for £1k. Replacement internals are c.£350 but with labour to fit (sadly I’m not that mechanically skilled!)
Labour to do the whole box out/back job... I’m hearing 10hours but that seems quite a lot.
Option 1 - http://www.gearboxman.co.uk/psgearboxes.html
Option 2 - https://tvr-parts.com/tvr-parts/part-details/tvr-f...
The cars currently with my TVR specialists in Surrey but I’ve also been recommended to consider Python Racing.
Any help much appreciated!
Cheers
(The cars had engine, suspension and alarm refreshed in the last 18months so was hoping for nothing else major for a while but hey ho, it’s a Cerb’ and I still love her).
I think I saw yours this morning while I was dropping off some parts for mine (black 4.5) - I was told the box went at Rockingham? 
Personally I would simply replace with a reconditioned unit. I guess the close ratio might be good if you mostly tracked the car, but I like the ability to pootle about when the conditions require which I suspect you would lose.
The cost of a recon versus internals seems odd when set against the warranty aspect, and I would always look for a warranty, which is why I would go for the full recon unit.
Personally I would simply replace with a reconditioned unit. I guess the close ratio might be good if you mostly tracked the car, but I like the ability to pootle about when the conditions require which I suspect you would lose.
The cost of a recon versus internals seems odd when set against the warranty aspect, and I would always look for a warranty, which is why I would go for the full recon unit.
Thanks both - yep, swopping the whole ‘box for a new unit and with better internals seems a good option.
the close ratio option I believe has a longer first and better stacking mid range whilst still being good for 160+ so seems a decent option as well as being more robust.
That’d be me you saw - sorry for not saying ‘hi’!
At 109db static (
), it won’t be going on any more tracks though. It was the TVRCC Cerbfest at Rockingham without a noise limit(!) and pretty much the last time to drive the circuit before it sadly closes. I’ve had the Cerb 18months now and enjoyed it hugely but it’s so fast, it seemed a good opportunity to explore it safely on track - the plan was to do a few laps, get more familiar with the handling and head home very happy. Whilst it was a brilliant experience and great to see so many other Cerb’s out there enjoying themselves, it’s a shame it turned out to be a bit too short lived!
Glad to make it to the garage after juggling traffic and roundabouts with limited gears!
Will explore the options some more and listen to any more tips before deciding what to do.
the close ratio option I believe has a longer first and better stacking mid range whilst still being good for 160+ so seems a decent option as well as being more robust.
That’d be me you saw - sorry for not saying ‘hi’!
At 109db static (
), it won’t be going on any more tracks though. It was the TVRCC Cerbfest at Rockingham without a noise limit(!) and pretty much the last time to drive the circuit before it sadly closes. I’ve had the Cerb 18months now and enjoyed it hugely but it’s so fast, it seemed a good opportunity to explore it safely on track - the plan was to do a few laps, get more familiar with the handling and head home very happy. Whilst it was a brilliant experience and great to see so many other Cerb’s out there enjoying themselves, it’s a shame it turned out to be a bit too short lived! Glad to make it to the garage after juggling traffic and roundabouts with limited gears!
Will explore the options some more and listen to any more tips before deciding what to do.
Try these http://www.astonmartingearboxes.co.uk/products/
I bought replacement parts for my gearbox from them and very very knowledgeable and helpful.
Simon.
I bought replacement parts for my gearbox from them and very very knowledgeable and helpful.
Simon.
Don't go for a close ratio box unless you've driven a car with one fitted
Your description of the issues suggests that the clutch is at least part of the issue, and may have caused the GB problems
The T5WC is a remarkably simple gearbox, even I have managed to fix one
Most parts are easy to source, but the TVR specific parts (e.g. input shaft) are a nightmare
If you can select reverse easily, then the clutch is releasing properly, if not then some if not all of your issues are clutch related
Good luck
Your description of the issues suggests that the clutch is at least part of the issue, and may have caused the GB problems
The T5WC is a remarkably simple gearbox, even I have managed to fix one
Most parts are easy to source, but the TVR specific parts (e.g. input shaft) are a nightmare
If you can select reverse easily, then the clutch is releasing properly, if not then some if not all of your issues are clutch related
Good luck
Bollycerb said:
Try these http://www.astonmartingearboxes.co.uk/products/
I bought replacement parts for my gearbox from them and very very knowledgeable and helpful.
Simon.
Thanks for the tip Simon - I will doI bought replacement parts for my gearbox from them and very very knowledgeable and helpful.
Simon.
ukkid35 said:
Don't go for a close ratio box unless you've driven a car with one fitted
Your description of the issues suggests that the clutch is at least part of the issue, and may have caused the GB problems
The T5WC is a remarkably simple gearbox, even I have managed to fix one
Most parts are easy to source, but the TVR specific parts (e.g. input shaft) are a nightmare
If you can select reverse easily, then the clutch is releasing properly, if not then some if not all of your issues are clutch related
Good luck
Thanks for the advice - will look harder at what’s actually gone wrong with it before taking a plunge on a new box then. Your description of the issues suggests that the clutch is at least part of the issue, and may have caused the GB problems
The T5WC is a remarkably simple gearbox, even I have managed to fix one
Most parts are easy to source, but the TVR specific parts (e.g. input shaft) are a nightmare
If you can select reverse easily, then the clutch is releasing properly, if not then some if not all of your issues are clutch related
Good luck
Don’t think it’s the clutch - reverse is still absolutely fine and setting off in 1st and running in 2nd seems fine although they were occasionally hard to select today enroute to the garage (took a couple of goes at times, to slot in from neutral).
The clutch release bearing has been whistling for a while (in neutral, with the clutch fully released) but that was supposed to be new with the new clutch and flywheel fitted c.6k miles so I’d assumed not an issue.
Only other theory was if it’d lost all its oil for some reason but it was only serviced in May and no tell-tale patches on the ground to be seen.
You're assuming it's the gears themselves that have gone. It might well be the synchros themselves or the hubs. Prematurely worn synchro or damaged synchro hubs could be indicative of a clutch problem in that drive may not be fully disconnected from the box before you try and shift gears resulting in worn friction material or blunted points on the synchro hubs.
Ring Readman Racing and talk to him. He's ex-factory and will do a good job for less than you might expect. He also offers (or at least used to) a close ratio 1-4 gearset with original 5th if you're interested. I'd warn against CR in a car used primarily on the road though. The Cerbera is faster than most other cars when creeping along at idle in a traffic jam and a CR box will make that worse so you'll be forever on the clutch in a slow moving queue.. Plus the higher 1st gear is likely harder on the clutch so it'll wear quicker.
Ring Readman Racing and talk to him. He's ex-factory and will do a good job for less than you might expect. He also offers (or at least used to) a close ratio 1-4 gearset with original 5th if you're interested. I'd warn against CR in a car used primarily on the road though. The Cerbera is faster than most other cars when creeping along at idle in a traffic jam and a CR box will make that worse so you'll be forever on the clutch in a slow moving queue.. Plus the higher 1st gear is likely harder on the clutch so it'll wear quicker.
Shame you didn’t get to enjoy the day as much as you should have 
I understand the rating (330 torques) of the T5 close to the limit for the application in any cerb, add in more bhp than it is rated for some spirited driving and 15-20 years... it will happen to all these cars at some time.
I’m not sure if the information is useful but i did quite a bit of research into T5 replacement for my supercharged cobra and bought an Astro T5 (650 torques) from the states https://astroperformance.com/ they have developed out a lot of the weaknesses and is the T5 of choice for motorsport over there (I’m doing my best to resist using the words ‘drag’ ‘tranny’ and ‘strip’ in one sentence - what is it with those guys!)
Exchange rate has dipped a little since I bought mine but they were pretty much the same price as a standard box over here. If you are interested in bulletproofing It may be worth dropping an email to Tony at Astro so see what he can do (I don’t know if he has built a box for any tvr’s but it would be good to know if has/can) I think it may be a Chevrolet shaft that you need but you may want to check this and the ‘shifter’ position or go the whole hog and get the 28 splinter and a better clutch, I went for a McLeod dual plater - it’s light and very good. He also does upgraded parts and rebuild kits if you Want to keep yours going and the labour works out o.k.
Hope you are back on the road soon!
I understand the rating (330 torques) of the T5 close to the limit for the application in any cerb, add in more bhp than it is rated for some spirited driving and 15-20 years... it will happen to all these cars at some time.
I’m not sure if the information is useful but i did quite a bit of research into T5 replacement for my supercharged cobra and bought an Astro T5 (650 torques) from the states https://astroperformance.com/ they have developed out a lot of the weaknesses and is the T5 of choice for motorsport over there (I’m doing my best to resist using the words ‘drag’ ‘tranny’ and ‘strip’ in one sentence - what is it with those guys!)
Exchange rate has dipped a little since I bought mine but they were pretty much the same price as a standard box over here. If you are interested in bulletproofing It may be worth dropping an email to Tony at Astro so see what he can do (I don’t know if he has built a box for any tvr’s but it would be good to know if has/can) I think it may be a Chevrolet shaft that you need but you may want to check this and the ‘shifter’ position or go the whole hog and get the 28 splinter and a better clutch, I went for a McLeod dual plater - it’s light and very good. He also does upgraded parts and rebuild kits if you Want to keep yours going and the labour works out o.k.
Hope you are back on the road soon!
G Cressey said:
Thanks both - some very useful pointers there. Rapidly going off the CR idea in favour of a like-for-like fix with increased resilience for the power. I’ll hit the phones to see if some progress can be made and will update the thread accordingly.
I think you have made the right choice here.Call Readman racing, he builds many if not all the gearboxes used in the TVR challenge racing series.
He built mine a few years ago after I had repeated failures, I went with the quaife semi straight cut option and the result is a much stronger box and slicker shift as well.
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