The V8 Owners Forum -

hi all,

Does anyone know the major differences between the ford T5 gearbox and the TVR T5 gearboxes.

Are the ratios the same?

Size wise which one has the gearlever furthest back?

Which bell housing is needed to mate to the rover v8?

Which one would be best for 300bhp approx.

Any size info would be good too, think of changing my LT77 for one.

cheers

scott

When you say Ford T5, I assume you mean Cosworth T5 and not American Ford T5.

The following is what I know,

The Cosworth T5 has the gear lever furthest back ie Right above the output shaft seal area.

The TVR output shaft is a larger diameter than a Cossie T5 so I would say the TVR is stronger. (27 spline against 25 Spline)

I believe the gear ratios are the same.

The bellhousing is usually from a TVR rover v8. But, if you are using a Cossie T5 box you will need to machine the gearbox front cover 5mm or so to fit in the circular opening in the TVR bellhousing.

The sleeve which carries the clutch release bearing is slightly larger on the TVR and the Cossie T5 sleeve is also bigger than the LT77 sleeve. So, a TVR box will need the TVR carrier and an LT77 carrier will need to be reamed out slightly to fit a Cossie T5.

Hope this helps

Denis

I always thought the US T5's used a different input shaft too...and could well be multiple variants as well ?
Length aside, one is 10 spline vs 23 spline ?


And also seen someone say the clocking of the box is actually canted towards the left side on the US T5's

Whether that's the front flange or in the bellhousings themselves I dont know. Although it's supposed to be a small amount so maybe not a big deal.

I've never had either, so just going from what I read years ago.

You have the bog stock T5 then the T5 world class (WC) better bearings etc + various tail housings + the differences already mentioned http://www.5speeds.com/t5/ Paul is the man on the T5 http://www.5speeds.com/t5.htm

just cant find enough information about these boxes, and the mods needed for my westfield.....

Plan is to stick to a refurbished R380 gearbox to replace my LT77.

The T5 idea would be nice one day, when ive won the lottery.

worth a thought.....

regards

scott

Hi Scott,

I have a Cossie T5 in mine and ordered the chassis to fit so i can't comment too much on any work needed. But you are at least looking at moving the mount - for the T5 the mount is just a flat plate across the bottom two rails with a Type9 style rubber mount on it. There is a matching bit bolted to the bottom of the gearbox that you would have to source if missing from any Cossie box you find.
The T5 case is also a bit wider than the LT77 and it runs very close to a couple of chassis tubes.
Then you need a new prop shaft.
Then you need a belhousing - either from someone like John Eales or from a TVR. A TVR bellhousing will need the bulge chopping off the top that makes up part of the gear linkage in a TVR (I think).

All in I think it's quite expensive to get working:
Second hand Cossie T5 (unknown condition!) £150
T5 rebuild £650
John Eales bellhousing (inc concentric slave) £350 (at the time, seem to be even more now!)
Prop shaft £100 ish
New clutch £can't remember
Spigot bearing for crank £few quid

Then add on another £300 to swap over to an AP concentric slave from the SAAB one - the AP one doesn't leak!!!!

I'm using a bronze spigot at the moment but some say you should use a roller bearing. Can't see it makes much difference.

Gear lever location is spot on - for me - i just fitted a slightly shorter stick with a bend in it.

I'm using a 3.14 diff which helps with the ratios.

Oh yeah and I think the T5 came in at 42kg, about 10 less than the LT77. But it's a costly way to save 10kg

Hope that helps.
Mike

Hi mike,

that just the type of info I was struggling to find out....

A pic of the underneath would be really good if you have one, as I probably need to find out if the T5 would fit my chassis, as mine was ordered with the LT77 in mind.

I would expect the T5 to cost 2-2.5k as an upgrade, but I'm fine with that if it is worth it in the end, and would be much better than my knackered LT77.

Struggling to find any pics of a t5 in a westfield.

cheers

scott

Surely the 380 would be handiest option anyway ?

Given how light the Westfield is, will it really trouble the gearbox ?

Other option ( at cost ) might be the W-series Toyota boxes. They're all alloy and not massive. although not sure how they fair compared to a T5 for size.

Hope these help, they are some photos i took along the way

You need this bit on the Cossie T5:


This is where the mounting plate is:


A shot of the other side of the tunnel:


Position of gear lever and highlighted mounting plate:


Huge bell housing!!!:




This is the AP slave i ended up with, the SAAB one supplied was 'supposed' to seal against the bell housing but never did. I had to have the mounting surface machined in order to get it centered and the correct distance from the clutch:


Gear lever position:



Mike

hi mike,

wow those pictures are what I was after, many thanks.

Helps me understand the problem better now.

Not too worried about the gear level position now, as looks very similar to mine now, only really gearbox mounts to work out.

Will do some more measuring at the weekend....when I have time.

thanks again for your help.

regards

scott

I put a T5 WC and bell housing from my TVR Griffiths 500 donor. I had to make up a remote gear level as WC was too far forward. Otherwise it was easy but mine is a Dax Rush. Plenty of installed pictures if you ever need them.

Cossie (top) vs WC.

Compared to the LT77, you will love the first gear ratio of the T5.

Also, I seem to recall that it is possible to swop tail housings to get the shifter where you want it. However, the housing needs to be machined to take the sleeve bush where the output shaft is larger. Downside is that you need both boxes to get all the bits necessary.

DEVONMAN wrote:Compared to the LT77, you will love the first gear ratio of the T5.

You should try a Cossi T5 with Quaife close ratio gears with the tall first gear. (2.5:1)

From memory I think that I could get to 53mph in first gear if I let my engine rev to 6k. Of course I don't do this, I change gear at about 30 mph then let it rev out in second which is equates to 80mph. Even with the tall first I can drop the clutch at 1000 RPM and it won't stall the engine, I guess having a fairly light car and a 4.6 engine helps here.

Edit.. Just found a screenshot of the gear calc tool that I used when I worked all of this out. I've never sussed out posting pictures up but the ratios that I used with a 3.36:1 give the following top speeds for each gear.

Gear ........... Ratio ................ Speed at 6k RPM

1 .............. 2.527:1 .............. 53
2 .............. 1.675:1 .............. 80
3 .............. 1.259:1 .............. 107
4 .............. 1.000:1 .............. 135
5 .............. 0.870:1 .............. 155

I used a JE bellhousing which came with a supplied concentric slave, I though that the slave was from a Transit van but it may well have been from a SAAB. The hose fittings that JE supplied were crap, they leaked sieve! I used my own fittings and it's be OK for 3 years. The position of the slave is very important, when everything is new it needs to be very near the END of its travel when the clutch pedal is pressed, as the friction plate wears the slave piston at-rest location moves further and further up is cylinder. I did get this wrong at first and when I pressed the clutch the piston popped out of its bore!

I ended up spending a load of money getting the bellhousing machined as the spigot bearing did not engage correctly nor did the clutch friction plate splines. From memory I had over 10mm machined from the back of the bellhousing, the back of the bellhousing is 'blind' so the recesses in it needed machining out.

Now if I had one of the thicker RV8 flywheels fitted the clutch spline engagement may have been OK without the machining but the spigot bearing engagement would still have been poor or not at all!

I did consider telling JE all of this but I had already waited 10 months for a set of close ratio gears for a R380 gearbox which then did not fit my gearbox so I had had enough of him. Also he knows everything so he did not need to hear a customer telling him that his bellhousing needed a load of work doing before it can be used!

Maybe people are using it without any machining but the input shaft of their gearbox will be waving about in the breeze due to a lack of support and the splines on the input shaft will only be engaged by about 10mm. (This is about half the available width of the splines on a standard Borg and Beck style of friction plate. My plate has an offset boss which is 30mm thick, I have 29mm of engagement which is nice!)

AJMHO!

Dig around and ye shall find ..

http://www.moderndriveline.com/Technica ... tremec.htm

http://www.moderndriveline.com/Technica ... mec_t5.htm

http://www.moderndriveline.com/Technica ... istory.htm

http://www.moderndriveline.com/Technica ... n_spec.htm

and other places too