Fitfth gear broken in T5 gearbox

[Sardonicus]

Contact the repairer , it's obviously a no brainer after just 6 months are not long

[TwinKam]

Suggest that you post this also on the Cerbera forum, as Cerb 'boxes have a harder life than Chims (with the exception of Peter's/Phazed's ) and owners over there have experienced this, notably UKKid

Edited by TwinKam on Monday 22 July 08:40

[DangerousDerek]

TwinKam said:

Suggest that you post this also on the Cerbera forum, as Cerb 'boxes have a harder life than Chims (with the exception of Peter's/Phazed's ) and owners over there have experienced this, notably UKKid

Edited by TwinKam on Monday 22 July 08:40

Hey, my T5 has had more abuse than Peters!

[ukkid35]

The problem with 5th is that it is a press fit, with just a circlip holding it in place

With enough torque the circlip opens up, and 5th then slides up the mainshaft



The replacement was a very tight press fit, so I doubt this one will do the same

[Dominic TVRetto]

Thought for the OP - this might be the time to look into available options for a longer 5th gear, if you are so inclined.

I've always thought the gearing could/should be longer - at least the top gear for low RPM cruising... The revs always seem way too high at 70, and a longer 5th gear could improve this (therefore mpg) without affecting acceleration in the lower gears...

Just a thought...

[ukkid35]

Dominic TVRetto said:

Thought for the OP - this might be the time to look into available options for a longer 5th gear, if you are so inclined.

I've always thought the gearing could/should be longer - at least the top gear for low RPM cruising... The revs always seem way too high at 70, and a longer 5th gear could improve this (therefore mpg) without affecting acceleration in the lower gears...

Just a thought...

There are several different 5th gear sets available, mainly in the US

The problem is that TVR has a 27 spline mainshaft, which doesn't appear to be used by any other model

So you could use a different gearset, but you'd need to swap out the mainshaft and modify the propshaft to use an appropriate yoke

I have considered doing this in order to fit the much more robust 'Sebring 5th Gearset', but I've not actually done anything about it

https://www.5speeds.com/t5/s80.html

At $250 it's not actually any more expensive than the standard TVR 5th gearset, which you can't seem to get from any of the usual suspects anyway

[Sardonicus]

Paul Cangialosi @ 5speeds.com was talking of getting some manufactured IIRC for the 27 splinners

[Rufus Roughcut]

On my box the circlip is prevented from 'riding' up the shaft by a recess, it made removing my gear more difficult as I had to press it on further before I remove the clip.

Sorry i don't have a specific photo however you can just make it out if you zoom in.

Ignore the date

[MisterT]

This is my fifth, which as Rufus Roughcut says has a recess in the gear which houses the snap ring which hopefully means it can't spread under load and slip up the main shaft. I think some of the later TVR T5's don't have this recess in the fifth gear. It may be relevant that mine is (I think) a .73 overdrive not the .8 that others have, it also meant I could take the mainshaft out of the box without the messy cutting of the bearing race that the larger dia 5th requires.

[Sardonicus]

What did you decide to do with this poor retainer/thrust plate ?

[MisterT]

This...

[Sardonicus]

MisterT said:

This...

Good call I have the same kit

[ukkid35]

Here's some advice that I'd not seen before

astroperformance - US eBay seller said:

5th Mainshaft Gear Internal Splines are very "tight" from Manufacturer. It is recommended to either Shot-Peen both the Internal Spline of 5th Mainshaft Gear as well as the Outer Splines of Output Shaft to insure only a 1-Ton Press Fit is achieved. If the Gear is pressed on with more effort it puts the 5th Mainshaft Gear at higher risk of "splitting/cracking" upon installation and/or being ran.

I definitely used a hell of a lot more than 1 ton to press it on

[TwinKam]

ukkid35 said:

Here's some advice that I'd not seen before

astroperformance - US eBay seller said:

5th Mainshaft Gear Internal Splines are very "tight" from Manufacturer. It is recommended to either Shot-Peen both the Internal Spline of 5th Mainshaft Gear as well as the Outer Splines of Output Shaft to insure only a 1-Ton Press Fit is achieved. If the Gear is pressed on with more effort it puts the 5th Mainshaft Gear at higher risk of "splitting/cracking" upon installation and/or being ran.

I definitely used a hell of a lot more than 1 ton to press it on

Put it to the back of your mind, Paul, nothing you can do about it now!

[MisterT]

My press is a 12 tonne one and it took a lot of pressure to shift the fifth gear down the mainshaft to release the snap ring. Not sure it was the full 12 tonne, it's only a diy press from one of the cheapy eBay tool stores, and I'm not sure I'd be happy using it to the swl limit, but it was probably more than 1 tonne.

I emailed Paul C at 5speeds in USA to ask him about it and the forces needed, but he didn't seem too concerned, 'just press it on further to get clearance to remove the snap ring' was his response. When it came to refitting I think less force was needed, but only a subjective feeling.

ETA his only caveat, I recall to to make sure the fifth gear was fully supported around it's perimeter when in the press

Edited by MisterT on Wednesday 31st July 10:31

[ukkid35]

TwinKam said:

Put it to the back of your mind, Paul, nothing you can do about it now!

Actually what I'm concentrating on is fixing the spare gbox, but as I mentioned, I haven't been able to source a replacement 5th for the 27 spline mainshaft

I don't want to be forced to replace the mainshaft with a 28 spline version so I can source a gearset, because I'll have to get a spare propshaft as well and swap the yoke

I was too cheap to buy a spare 5th when it was available, serves me right!

[ukkid35]

I decided to buy this in the end

https://www.ebay.com/itm/Mustang-Borg-Warner-T5-Tr...

This is a 1.6 ratio gearset with 32/20 teeth, just like the standard TVR gearset with 53/33 teeth which is also 1.6

Unfortunately it will require a Ford 28 spline mainshaft and yoke, but those parts are not unobtainium

I don't know whether the 5Speeds Sebring version of this gearset is significantly more robust, but it is significantly more expensive

https://www.5speeds.com/t5/s80.html

Unless you check this page in which case it's roughly the same price

https://www.5speeds.com/cart/index.php?route=produ...

Edited by ukkid35 on Wednesday 31st July 21:42

[fablu]

Follow up!
Finally got the car to a workshop, the retaining ring had snapped in half so fifth gear was on the loose.

New one fitted, lets hope this thread isnt resurrected in six years again

[phazed]

When mine was let loose, floated to the bottom of the box and luckily didn’t damage anything! Continued on my journey using fourth gear as top gear!

[ukkid35]

fablu said:

Follow up!
Finally got the car to a workshop, the retaining ring had snapped in half so fifth gear was on the loose.

New one fitted, lets hope this thread isnt resurrected in six years again

Thanks for that update

Would be great to hear who has a supply of 5th gear sets