Installing T5 Gearbox & Programmable speedo, Precat Griffith

[stevesprint]

Steve (stesrg)
Further to your interest in my T5 Gearbox and speedy cables programmable speedo installation in my Precat Griffith I thought it best I reply in a new thread.

carsy said:

You want a T5 from a Tuscan. Apparently they go straight in without any chassis mods. I also think jonn reid can supply you with the correct fitting for the T5 if you can't find a Tuscan one.

I think stevesprint went this route. Give him a shout.

Steve (stesrg)
Sorry a little off topic but you did ask.
Fitting the later style T5 with the lever further forward is one of the best mods I did to my Precat Griff. The Griffith 500 external gear lever linkage would foul on the top cross member, Quinny can confirm.



I personally welded the Griff 500 style gearbox mounts onto the bottom chassis rails but you don’t have to as g8ape designed and fabricated his own cross member utilising the existing cross member bolt pick up points on the chassis. It might be worth contacting g8ape as I know he had a few extra brackets made. He also had some beautifully machined gear lever adapters made.
You can contact him from this thread. http://www.pistonheads.com/gassing/topic.asp?h=1&a...

You can see some of my T5 pictures here
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

You’ll also have to change your Speedo to one of these from speedy cables.


They are definitely worth the 3 months order time as its a perfect match and the calibration is programmable via the trip-reset button plus they work with virtually any road speed sensor. Don’t forget you'll also have to fit a new speed sensor on the top of the diff. As your going the Turbo route I assume that means you won’t have to worry about compatibility issues with the old 14CUX ECU that I'm obsessed with.

If you are serious about this mod I’ll email you some more pictures.
Good Luck
Steve

stesrg said:

From bonets to brakes to gearboxes lol.
Seriously yes I will need a better box if I am looking to get 400 ponies !!
I take it the one on the right is the std box and the one on the left is the Tuscan ? The one to fit ?so you have to mod the prop? Speedo do they need my old one as I will order that now ?
Fabrications ? I am a fabricator by trade so have access to CNC plasma and lathe ,milling machine tig for alloy so drawings would be good or a pattern and I would make a better one in return ? (A long time ago I was going to fabricate a Griff chassis in stainless steel )
Yes any help in this conversion will be appreciated ,swaps beer tokens in return
Ste.

Steve (stesrg)
The Gearbox on the left is from a Griffith 500 with the external linkage to bring the gear lever further forward and would foul on the chassis top cross member.

The middle gearbox is the later Tuscan/Sagaris style with the lever cast further forward in line with the LT77 gear lever.

The one on the right is from my precat, they are basically a Rover SD1 LT77 with TVR’s own offset gear lever housing.

Yes, you have to change the propshaft flange for a splined sleeve joint or use an early Griff 500 or Chimmy prop that had a GKN diff with a T5, you can see the propshaft joint is my bracket picture below.

Speedy cables do reuse your old speedo needle and hopefully you could post it to them when the new speedo is nearly ready.

Here’s a picture of g8ape gear lever adapter and cross member that a voids welding the chassis.






Here's my Griff 500 style brackets welded to the bottom chassis rails with my adapted Griffith 500 bottom gearbox bracket and gear lever bracket.



Good Luck, Steve Sprint

[stesrg]

Thanks Steve, I am laying the new griff off in sept as the mot expires then will start my engine box and chassis renovations , in the meantime will be finishing off the interior hopefully for the summer so should be able to get to go to some meets

I have Emailed g8ape and hopefully he will reply , looking at the mounts don't think I can better them unless I use stainless steel hence no powder coating or rust

so save me destroying my speedo I will be looking for a pointer

All information will be appreciated

Ste .

[Hoover.]

Don't leta garage do it unless you want a £4k bill...... steve will say a good a upgrade, my view point is based on £'s/enjoyment....... I will it is nicer experience..... but 2nd gear on the rover box is longer

[stevesprint]

Hoover. said:

Don't leta garage do it unless you want a £4k bill...... steve will say a good a upgrade, my view point is based on £'s/enjoyment....... I will it is nicer experience..... but 2nd gear on the rover box is longer

Hoover,
Thanks for your thoughts and sharing you garage experience, I definitely "will say a good upgrade".

Your “£'s/enjoyment” warning makes me appreciate how much us home mechanics really save. I installed my T5 for the price of the parts that I obtained for £750 and therefore makes it one of my best “£'s/enjoyment” modifications. In fact it cost me even less as afterwards I sold my old LT77, bellhousing and prop. Please note I haven't included the cost of the programmable speedo as I had already replaced my original speedo a few years prior when it first broke.

I agree the T5 a “nicer experience” plus its stronger and the gear changes are quicker and was therefore the obvious choice for the Tuscan challenge race cars right from the start, even before the Griff was born with the LT77. The T5’s slightly shorter 2nd gear is better for acceleration plus you have the option of a longer 5th gear.

I would like to take this opportunity to thank Quinny for selling me his faultless and built proof T5, the faster the gear change the smoother it gets and you can’t say that about the LT77.

Cheers, Steve Sprint

[stesrg]

Steve sprint
Just a thought I had, what's the problem going the R380 Gearbox route ?

Ste .

[stevesprint]

stesrg said:

Steve sprint
Just a thought I had, what's the problem going the R380 Gearbox route ?

Ste .

Sorry, I have no R380 experience but sounds like a good option especially after reading this very informative website. http://www.gomog.com/allmorgan/gearboxes2.html

I’m very biased because I installed a T5 in my TR7 3.9i back in 1992 after destroying 2 LT77s and then never had a single issue with a T5 in the following 22 years.

[griffdude]

Ste,

These guys are LT77 specialists if that helps

http://www.ashcroft-transmissions.co.uk/manual-gea...

[stesrg]

Thanks guys .....just go to work out what's best now the Ashcroft lt77 replacement sounds less hassle but is the T5 stronger ?
I am trying to budget on about £1200-1500 is this about right ?

thanks again

Ste .

[Hoover.]

At the time I changed mine I looked at the R380 box but lack of knowledge what was required to make it fit put me off.....

I remember before I looked into gearbox change, everyone was saying that to fit a T5 box would require the cutting the tunnel aperture to allow the gear stick in to the cab and thus require a retrim of the tunnel, then someone announced that a T5 from a Tuscan would fit due to the gear linkage...... with that in mind it put me off the R380 box as no-one could/would give me a straight answer

[stevesprint]

Hoover. said:

At the time I changed mine I looked at the R380 box but lack of knowledge what was required to make it fit put me off.....

I remember before I looked into gearbox change, everyone was saying that to fit a T5 box would require the cutting the tunnel aperture to allow the gear stick in to the cab and thus require a retrim of the tunnel, then someone announced that a T5 from a Tuscan would fit due to the gear linkage...... with that in mind it put me off the R380 box as no-one could/would give me a straight answer

I installed the Tuscan/T350/Sagaris T5 as I found out all the last 100 Griffith SE have the later style T5 but with the exhaust tray upside down. Luckily I managed to keep my tray the correct way up.

[Hoover.]

Yep that's it now.... the T5 from a Griff wouldn't fit, as per my discription above

[stesrg]

After loads of thought and the fact I will be removing engine /box /diff and all my suspension arms I may as well go the T5 route ;-)

List req.
box with s10 remote ( how many spline will I need to look for )
Old pre cat speedo (needle required)
Mount ( may as well fab my own up as the car will be up in the air in the fab shop !!)
Have I missed something else ?

Ste.

[Quinny]

stesrg said:

After loads of thought and the fact I will be removing engine /box /diff and all my suspension arms I may as well go the T5 route ;-)

Have I missed something else ?

Ste.

Bronze bush in end of crank...

[stevesprint]

stesrg said:

Have I missed something else ?

Bell housing
Prop-shaft with 27 splines yoke (adapt yours or buy one off an early Griff 500)
g8ape’s gear level adapter looks good
Possibly Bearing carrier
Road Speed sensor http://www.caigauge.com/page18.html
Road speed sensor crown wheel (from TVR breakers)
Programmable Speedo
T5 spigot bearing (Well remembered Quinny)

Sorry, I hope this list hasn’t put you off.

Here’s a third method to support the rear of the gearbox.

I actually considered this approach first as it wouldn't require welding the later style Griff 500 gearbox mounts to the chassis, but didn't as I would of had to lower the exhaust. This approach may explain why TVR lowered the exhaust on the last 100 SE Griffith.

Should you require further information please do not hesitate to PM me or maybe its easier to discuss your installation on the phone.

[FactBV]

If it is of interest to anyone, at the time I bought one of these bespoke T5 gearbox conversion cross members that I think Steve had made, with 2 x new cotton reel bushes. The workmanship is fantastic. I also bought the offset gear stick adaptor anodised blue including the insulating bush and also 1 x 2nd hand Alloy gear stick . I think I paid about £250-£300 for them. A lot of work had gone into it and it was just a no brainer to have an easy bolt on solution. However, I have sold the car that I had intended to fit it to so if someone gave me say £275, what I paid for it, they could have it.

[stesrg]

stevesprint said:

Bell housing
Prop-shaft with 27 splines yoke (adapt yours or buy one off an early Griff 500)
g8ape’s gear level adapter looks good
Possibly Bearing carrier

Road speed sensor crown wheel

Sorry, I hope this list hasn’t put you off.



Should you require further information please do not hesitate to PM me or maybe its easier to discuss your installation on the phone.

Thanks will phone when it comes to crunch time ....
Bell housing why won't my lt77 fit ?
Also road speed sencor crown wheel what does this look like ?
Thanks ste.

[stevesprint]

stesrg said:

Thanks will phone when it comes to crunch time ....
Bell housing why won't my lt77 fit ?
Also road speed sencor crown wheel what does this look like ?
Thanks ste.

Sorry, I'm afraid the LT77 bell housing doesn't fit the T5 so TVR had a special bell housing cast.

Here's an unmolested Griff 500 crown wheel in situ with my home made sensor bracket above, you could use a Griff 500 bracket but not a 500 sensor.


16 pulses proved too many for the speedo and 14CUX ECU so I had to remove 12 teeth to make it work with both.

I believe the crown wheels are available with 16, 17 or 18 teeth so best to buy one with 16 teeth so you can end up with 4 equally spaced teeth.

[Hoover.]

Looking through this gives me a much better understanding of what was involved when the garage did my conversion........ when my car is next on the ramps, I'll take some photos to add to this thread, as whilst the basics approach is the same I'm sure that some solutions have been approached differently

[Dgbroadhurst]

Hi Steve,

I am undertaking the same gearbox change. I have already obtained a T5 from a Tuscan so selector location is same as the middle box in your picture. My car is early Griffith 500 fitted with a horrible lt77 which is winning in 1,2,3. My car has done 50k so has just had a cam change and my mechanic told me to not even bother rebuilding the box as he said it will be same again soon.

Could I ask where did you obtain the selector and the box mounting brackets and could you tell me how to go about the prop shaft. Do I only need to replace the gearbox connection only as I already have a prop? Still looking for a bell housing secondhand.

Many thanks
David

Edited by Dgbroadhurst on Monday 31st October 17:39

Edited by Dgbroadhurst on Monday 31st October 17:40

[stevesprint]

Dgbroadhurst said:

Could I ask where did you obtain the selector and the box mounting brackets

Well done for taking the plunge, sounds like you’ve bought the best gearbox for the transplant.

I had a local engineering shop make my gear lever adapter block below that I had welded to part of a Griff 500 external linkage and also threaded the gearbox lever to screw it on to, sorry not very staight forward but the picture below should give you the idea.

You can see I chopped the T5 lever right down and had it threaded, plus I used a roll pin to stop is turning.




I took this approach as I wanted to use a Chimmy/Griff 500 T5 external linkage with the rubber bush between the lever and the gearbox to stop the heat transfer, it’s a bit crude but does stay cool and has proved to be very strong and reliable over the last 6 years.

G8ape also had his own blue lever adapter made in the previous posts and worth considering as his approach is simpler and you don't have to buy and chop up a Griff 500 external linkage.

My lower gearbox mounting bracket is an extended Giff/Chimmy T5 cross bracket, Griff 500 owners may recognise the centre cross section. You’ll have to work out were & how to extend the bracket in situ, if you can't get hold of the small cross mount don’t panic because BoostedChim made his own bracket from scratch, see http://www.pistonheads.com/gassing/topic.asp?h=1&a...

I hope your chassis has the T5 gearbox mounts on the lower chassis rails, if not you’ll have to make some and weld then on like I did, or you could use G8ape approach and make a whole cross member bracket (in 1st post above) to use the existing chassis bolt holes for the LT77 support.

Two different solutions to the same problem.

Dgbroadhurst said:

Could you tell me how to go about the prop shaft. Do I only need to replace the gearbox connection only as I already have a prop? Still looking for a bell housing secondhand.

Yes correct, you only need to change the LT77 flange for a T5 splined sleeve but I'll bet it will not be exactly the right length, I bought a Griff 500 prop thinking it would go straight in but I had to shorten it, I guess it may have been for a different diff.

If you are patience and try the TVR specialist you may find a bell housing at the right price, if not you could always try the TVR breakers.
Good Luck and don't hesitate to post any further questions.

Edited by stevesprint on Sunday 6th November 16:58