booner999

Hi all,

I know its only a matter of time before my diff or gearbox gives in so thinking about the future.

My Escort Cosworth is running Sierra 2wd running gear and thinking about a digger/stronger diff and gearbox.

Now the car is used most days, its not shy of the rain etc and it has a good stage 3 power.

The box at the moment feels nice and tight, no grinds etc. The diff has a slight whine on over run but again nothing major I dont think.

So that got me thinking.

What kind of money are the tremec rwd gearbox? is the 6 speed worth it? Would love a 6 speed if I can get the MPG up a bit and its not going to cost me much more for the box.

Is this a bad box to buy second hand? Heard they can be pretty bullet proof as running in big power cosworths etc..

But how much power will a Tremec box take? and also a 7.5 inch to 9 inch gripper diff take?

Just thinking about this at the moment, dont think I am going to go for anymore power from the engine as its more than enough for the road.

Idea please guys, do these gearbox's have straight cut gears? any in car footage of the sound the straight cut box makes etc? I love the sound of the straight cut gears but on the other hand, I use it alot so think it might grow boring after a while.....

thanks

Mark

JamesH

iTrader: (21)

Tremec TKO600 usually is around Ł2500 second hand, with everything needed to fit.

Don't get a 6 speed

I've not heard of any problem with one, second hand or not

It will handle more power than you'll ever put through it

They are not straight cut and make no noises when running

Miller 3

iTrader: (4)

The standerd t5 box will be fine up to 500hp if you give it a bit of respect

Jay,

iTrader: (4)

youve made the number 1 mistake doug its a cossy it wont get any

as james said about the box fit and forget ! the gripper's are brilliant BUT crown wheel and pinion are the weak link so get them treated and itll be fine or go for a supra diff wont lock so well but does the job of staying together

Rod-Tarry

The tko 600 will take 800ft-lb without problems been in mine for over 10 years . The T56 is not really suitable because 6th is way too tall & miles from 5th its a joke. Depending on the Torque you are expecting a 10.5" Jaguar diff will also take 800ft-lbs without a problem. A Cossie suitable 3.54 is available from a Diamler Limo. I gave a bottle of wine (Ł20) for mine & then Ł400 to recon it, been in for 10 years without a problem.

flannigan

iTrader: (1)

The Tremec is a indestructible gearbox but it is not the fastest unit changing gear and weighs a tonne I have just removed a Tremec tko600 from mine and replaced it with a cts/Quaife built t5 and it's much better IMHO

Miller 3

iTrader: (4)

I think im going to run a quaife stright cut unit in mine when it dies as i want a box that sounds like it has no oil in it lol

Jay too true mate ha ha

COCHYN

Like that cool little Lotus in Time Attack mate

Miller 3

iTrader: (4)

You know that mate, your hooked now aint ya lol

COCHYN

Weeeeeeeeeeeeeeeeeee, (2nd gear) weeeeeeeeeeeeee, (3rd gear) BAAAAAAAANG!!!!!!


CANT!!!!!

Sonic Boom

iTrader: (11)

You could go with the modern version of the T56 a TR6060 brand new they are Ł1295 and your can pick you 6th ratio so no need to run a silly 0.52 Viper top gear.
Rich

Gav Diamond

iTrader: (6)

I can change gear with my TKO a lot faster than I ever could with a T5 and have yet to miss a gear, that and its lasted longer than 200 miles, lol.

The CTS/Quaife gear kit gets very noisey after a while and I only know of about 2 where folks have not had selector fork and gear changing problems (I know there is obviously more but I have heard of quite a few people having problems with them) which is why I chose the TKO over this gearkit.

Gripper diffs are good but they do need regular maintainance and rebuilds to keep them at there best, I will soon be swapping mine out for a Supra diff so I can then have all quiet transmission again

pieterjan

iTrader: (4)

Talk to tony at turbosystems for a supra diff conversion.

johnyjn

iTrader: (1)

You like mine don't you

Miller 3

iTrader: (4)

I do indeed bud lol iv wanted to get one for about three years now but seeing as the car aint built yet its not that high on my list lol

booner999

OK Chaps, thanks for the info. Does the tremec box not have a new car kind of feel to it? Does it feel like a T5 with its change? I like the T5 gear change but if I was uprating and spending decent money I think I would want it to feel a little more modern than the T5 unit. I was also thinking about going down the hydrolic clutch as well again to give it that more modern feel and making the power more usable.

All just ideas at the moment, thanks for the details and input, all very helpful.

How much power does a 7.5 inch sierra rear diff last from a cosworth? I see they are only around Ł300 to buy, but then I guess a second hand gripper diff or as mentioned above a jag/supra dif could be bought for the same kind of money and then I just forget about it.

Rod, does the jag diff need much work/changes to the Sierra 2wd rear beam?

Jay,

iTrader: (4)

the gear change is manly to say the least lol there not as smooth as a modern box but still a good box to use , theres always a compromise

as for the diff well all i can say do you want to buy 3 cossie diffs a year and fit the things or fit a jag/supra one once ? the cossie diff is false economy

RWD_cossie_wil

iTrader: (9)

Booner, my TKO is out of the car at the moment if you want to come & measure the parts that are needed to fit it? Also got a jag rear end if you want a look at it?

vinge87

http://www.quaife.co.uk/shop/products/qbe69g-0

This is what im gonna use in my car......

ajamesc

Are you mad? you could have a tko a supra diff and a 6 degree rear beam plus a pocket full of change!!!!
I have a cts/bigtooth box in mine which i find fine and have had no problems with plus as for diffs a lot of it is how you drive! i have a gripper with an up rated cwp which i havent busted yet (but did bust with a standard cwp). But have a good friend who had a quaife 7.5 diff that he busted 4 times lol with less power and torque than me who now runs a supra diff

RWD_cossie_wil

iTrader: (9)

Love your Saff mate have you got a project thread?

booner999

I would love to mate but I am miles away

I dont plan on replacing anything until it breaks and by the sounds of it a supra/jag diff is the best way to go.

I am off to eBay to try find a diff and work out a price for all this lovelyness

RWD_cossie_wil

iTrader: (9)

How about a Ford 9"? Expensive but unbreakable & direct fit, and will always sell again easy?

DaveCrack

iTrader: (1)

How are the Supra diffs to drive? Someone mentioned they don't lock as well as Grippers do. Is there any upgrades you can do to them?
Been thimkin about replacing my diff sooner or later too.

vinge87

diff im using is a 9,75" from ford excursion with torsen (ATB) diff cost brand new Ł800

vinge87

Why pay Ł3000 for a diff like this??

booner999

wow that is a big diff..

OK So going to show my lack of knowledge on this. I am guessing with a bigger diff I will need bigger drive shafts to fit the diff?

Does anyone know what diffs bolt straight into the rear beam from a Sierra 2wd?

Wil, how much is alot?

Does anyone think this is overkill for a car under 400 bhp?

RWD_cossie_wil

iTrader: (9)

As above, direct fit, strong as an ox and will always sell very quickly, plus a good selection of ratios. Just another option alongside all the others.

RWD_cossie_wil

iTrader: (9)

Ford motorsport 9" from 2-3k, uprating is never overkill, but it would last well on T5 & 7.5" standard parts as long as you have a bit of mechanical sympathy.

Jay,

iTrader: (4)

well you could buy the cusco 1.5 way diff to fit the supra casing ect

vinge87

Yes, BUT Ł3000??????? A lot more than Ł800......You can then buy a almost complete wrc rear setup if u want

RWD_cossie_wil

iTrader: (9)

As I said, another option...

DaveCrack

iTrader: (1)

Thanks, that's another 1k on top of the supra conversion it self...

booner999

I do look after the drivetrain, not quick shifting, burn outs, donuts etc etc so the only time its under full strain is 2nd, 3rd and 4th. 5th is silly speed so tend not to bother with that. I never part depress the clutch and shift and have never grinded gear (reverse slightly) To be honest, if the current gearbox and diff in the car last me long enough then I might just get them rebuilt. I think the gearbox is very strong, must of recently been rebuilt

But if its going to fail once a year then I will spend some cash and do it once and right.

Jay,

iTrader: (4)

true but i only added that as a option , tbh the standard supra lock is that bad but like i comented it wont lock like the gripper as the gripper is plated

Martin-Hadland

iTrader: (2)

The 6th gear ratio isn't a joke when the box is being driven by a big capacity engine with loadsa low down grunt In fact its quite the opposite, you can have your normal 5 speeds and then drop it into 6th on the motorway and cruise economically.

Mark V8

iTrader: (2)

That's my plan



I'm using the Ford version of the T56 with 0.62:1 6th gear

Should give 31mph per 1000 revs in top.

DaveCrack

iTrader: (1)

You mean supra lock is'NT that bad or actually IS that bad?

peteh

iTrader: (3)

Are the problems with the supra diff been sorted yet......?

MAD Ade

iTrader: (1)

My old Quaife box certainly sounded like that Doug, was a great bit of kit though....