T5 Gearboxes

[PSI 304]

What do any of you guys know about them?

Im not really clued up on them but they're fairly well known for not being the strongest gearbox in the world. Im also not sure if i want (when the time calls for it) to go with a T56, more thinking stick with the bunky box and stay true to the cars factory fitment but just improve upon it.

So, the info im chasing is what commonly goes wrong with them once being fed a decent spoonful of torque? Whats the common direction when wanting to make them stronger? Stories? Workshop recommendations?

Thanks lads :)

[Turbo2.6L]

Ford variants break synchros & gears, usually gear 3.
No proven methods for strengthening as they are a shit box. Chryo treatment is probably the best bet though...

[ForgedV6]

I have a worn T5 in my Ecotec powered VK Commodore.

Cant go from 4th to 3rd, you need to trick 3rd by faking a change from 4th to 2nd then into the 3rd if your shifting down. Cant get reverse without going into 5th first then down into reverse.

Very 'knuckly' gearbox from the get go.

Dont know much about the internals of them though.

Work colleague 's husband races at Barbs with his VT V6 and uses a T5, has 4 spare in the shed though......

[Fusion]

I've broken my fair share of T5's, from snapping output shafts to sending 3rd sideways out of the box. How strong you want it depends on the size of your wallet. I know a couple of Saloon car teams spend upwards of $7000 on them using straight cut gear from PPG and what not. There is a company in the U.S. called G-force Transmissions that build beefed up T5's (straight cuts, dog ring engagement etc).

One common problem is the bearing retainer is a little weak. Meaning when you load up on the gearbox, it flexes allowing the gear cluster to move (hence smashing third can be a common issue). This can be fixed with a billet replacement. Also using high quality bearings and genuine TTC/Tremec parts does seem to help the life of the box

With a little bit of mechanical knowledge, a T5 is easy to rebuild yourself if you are that way inclined and feel you may break it often. (Manual can be downloaded from the TTC website).

[ClevoCapri]

I have seen a couple twist input shafts and break 3rd. They are easy to rebuild and relativly cheap.
I would go for a tremec 5 speed tko. There not the cheapest at around $3000 just for the box. But will take more torque.

[sprint347]

You can get T5 gearsets that are rated to 575ft/lbs from Astro Performance in the states. To put that figure into perspective, the Tremec TKO 500/600 names refer to their torque capacity in ft/lbs.

They're not cheap, approx $2k for the gearset alone but there are guys in the US running 9's on slicks with T5s. I was going to get one but opted for a T56 Magnum instead which is rated at 700ft/lbs because my HP goals have risen. That and the cases can fail in T5's which gearsets can't fix.

I'd look at a tko/t56 upgrade as the most cost effective option.

Oh and finally, T5's can handle large amounts of power... it's generally the hard shifts that kill these boxes, particularly 3rd gear as mentioned.

[PSI 304]

Well the car puts down 750nm (about 550ft/lb?) and box hasnt given up yet, but in saying that, i dont sit on the brake nor flat shift as i have some sense of mechanical sympathy. I don't see the box giving up for a little while yet but every now and again it feels like 2nd gear is becoming pretty worn. Was just looking at what people may have done before that was effectively. Better to have the information under my belt now than having to make a more rushed decision when the time comes.

Its not difficult to find a T56 for a commodore, but as i said i was just looking to stick with a T5 to stay true to the vehicle as it was from factory. The theme im looking for in the car is 'factory modified' if that makes sense? Leave the car fairly factory-like in regards to keeping standard displacement rather than a stroker, original 5sp gearbox, holden diff instead of 9" etc. but just improved upon (blower, cam, strengthened gearbox, rebuilt diff).

[Turbo2.6L]

Why? It's already been molested, so will never be a factory original car.
Just T56 it, E85, more boost etc etc :D

[sprint347]

I can appreciate the 'factory look', it's the same theme with my car so I'll be using a W2A, keeping the body/interior looking stock etc.

Driveline is another story :)

[ED40]

Shane, cant wait to see your car when its done bro. My mate has a magnum in his ED turbo and it feels strong!

A T5 will not accept any half decent kind of load!!! THEY HATE LOAD!
See here.. http://www.youtube.com/watch?v=lqb2C1X2X58

Regy off the forums here, has been through a few of them behind his turbo eb falcon. Rolling on the power, he just breaks them in 3rd gear.

I had a t5 in mine for a year and it was noisy buy the time i upgraded. It held on due to the fact i never rolled on in 3rd.

One Rat has a jesus spec t5 and has lasted for years now. I do think that the short diff ratio in his rear end helps to keep the load off the gearbox.

[PSI 304]

Why? It's already been molested

Hardly, its essentially a stock 5ltr ute with a whining device bolted to the top...but i do see what you're saying.

Im not trying to keep it an 'original car' of sorts but rather than throwing in a built LSx, T56, sheetmetal 9". Would be stupid fast and heaps of fun but i rather the idea of making improvements on what the car came with from the factory as i think there is too much emphasis on transplants in the modified car world at the moment.

Call me stupid or stupid, but fingers crossed it'll do what i need it to :)

[Scaf]

While on the topic of T5's anyone got a T5 crossmember for a vs commodore laying around? I'm chasing one.

[sprint347]

Shane, cant wait to see your car when its done bro. My mate has a magnum in his ED turbo and it feels strong!

A T5 will not accept any half decent kind of load!!! THEY HATE LOAD!
See here.. http://www.youtube.com/watch?v=lqb2C1X2X58

Regy off the forums here, has been through a few of them behind his turbo eb falcon. Rolling on the power, he just breaks them in 3rd gear.

I had a t5 in mine for a year and it was noisy buy the time i upgraded. It held on due to the fact i never rolled on in 3rd.

One Rat has a jesus spec t5 and has lasted for years now. I do think that the short diff ratio in his rear end helps to keep the load off the gearbox.

Thanks Carl, it'll be another 4 million years in the making but I'm sure it'll do a skid.

Did your mate have to do much tunnel bashing to get the magnum in and where did the shifter sit in relation to the factory one.

[VS5LUTE]

I've been through a couple, they're actually pretty strong box.. I give mine a hiding and they hold up ok. I would go the t56 though its not a hard conversion if you have hydrulics already..