Has anybody heard of this company before? I know the stock T-5 is weak and alot of guys are converting over to the t-56 trans. I have a friend with an 89 iroc with and L98 and he wants to change over to a manual trans. I told him to upgrade to a t-56 and he told me about g-force transmissions.
He has a stock L98 bottom end some AFR 180cc heads and a zz9 cam shaft. He also has an edlebrock intake a and some slp runners on the car. It has a lot of tourque and he dosen't want to snap the trans behind that motor.

What is it about the t-5 that makes it so weak? How much would a t-56 trans cost and what are the parts that are needed?

 

Yes they are a familiar company.

There are people on this board who have used that product. For some it was OK; for some, it was a disaster. I have no knowledge particularly of why, either way. No doubt you found lots of stuff more useful than that when you did your search before you posted the question.

The thing that makes the T-5 weak, is its overall weakness.

What would ordinarily make something weak?

The T-5 is no different. The shafts are very small, they are very close together which limits the OD of the gears, the bearings are small, the case is thin, and everything is as light as good design would require it to be for 4-cyl and 6-cyl type applications. It was designed for gas mileage in low-power light cars with small low-torque engines; not for high performance and racing durability in high-power, heavy cars with V8s, sticky tires, and drag-race-optimized suspensions to produce some traction.

The problem with the T-5 IS NOT that the factory used crappy metal to make the gears. If it was, then upgrading the gears would make it better. The problem is THE CASE, and just the overall smallness of everything; coupled with the tight tolerances (again, because everything is SMALL, a very SMALL change in how it fits together, is VERY LARGE proportionally); and, the extreme case-hardening applied to the moving parts, which allows them to be small, light, and efficient but also makes them prone to shattering.

The high-$$$$$$ gearsets IMO are appropriate ONLY for situations where you CANNOT swap to another trans; where the rules of your sanctioning body's classification require it, for example. You will find, as I have often posted, that by the time you buy the "special" gears and max out the T-5 to the most it can possibly be, it'll STILL be fragile, the "fuse" in your drive train so to speak; and you'll have MORE THAN T-56 money tied up in it, but it'll still just be a T-5, with the aluminum foil case that can't hold the gears in the right place and thus is an accident biding its time for the best opportunity to happen to you.

Much smarter financially, for a street car not subject to class rules and restrictions, that you want to just do it once and be done and move on, to put a T-56 in it.

 

Thanks for the info about the t-5. I'll pass the info along to my friend. I run a 700r4 so I am more familar with that trans than the t-5. I just knew that a lot of guys are putting in the t-56 over a worked over t-5, I just didn't know why.

 

to get a t-5 beefed up to about 600hp/550tq(estimates), would cost about $3000+.. i have most of the options from g-force.. upgraded mainshaft, upgraded case, gears, blah blah blah.. it works for me so far.. i'll put it to the test of power.. i hope to be close, if not in the 10's this upcoming season..

like sofa said, a t-56 is more practical.. i'm running 4.30 gears with the optional extra wide 0.59:1 5th gear.. there is a HUUUUUUGE step from 4th to 5th.. at 55mph, i go from 3050rpm in 4th to 1800rpm in 5th.. with the t-56 you have middle ground and the ability to upgrade to well into the 9sec range..

 

I know someone that tried using there products in his 96 296ci LT1...and he ABSOLUTLY HATES them. He was having a ton of trouble using there products. Im not sure what he ended up switching to but he was not impressed at all with there goods.


Jay

 

So from what you guys are saying the t-56 is the way to go. Where is a good place to get a t-56 trans?
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What about the richmond 6-speed trans, is that any good? I thought it only had 1 overdrive gear and not 2 overdrives like the t-56.

 

richmond trans is overpriced, and a pain to install in this chassis.

another option is the Tremec TKO 5 speeds, plenty strong and a little cheaper than a t-56 is you dont need the 6th gear.

check out Forte's Parts Connection

 

I agree with most of sofakingdom's points, however I don't see your friend with the slightly modded motor having a problem with the T5.

Sofakingdom is telling you the honest truth how it is with no fluff.
And he is absolutely 100% correct on the tech. But you need to sit down and thing about what your trying to do, how much your spending, and what kind of car it's going in. He has an '89 iroc, which is about what a $2500 car in mint condition. He's putting another 2k or so in bolt ons. Now you want to spend another what 2-3k on transmission stuff? I had about 11k into my fbody, that I couldn't even sell for $6k and I had timeslips to back it up.
Obviously cars are not the best investment, but you need to pick and choose what you should and shouldn't spend your money on...


I used T5's for many years behind a very fast fbody with sticky tires and it was fine.

I also used the pedal all the way over to the left, had my shifter stops set correctly, and didn't miss third gear.

My vette is getting a T5 too btw, because I can't justify spending $1300 for a used T56 transmission, that has a useless 6th gear that I cannot use anyway. They are hard to find, require specific components (hydraulics, clutch, bell housing).

The TKO option is nice too, My friend has a tko 3550 in his Cobra and it's a nice transmission to drive. But at $2000+ price tag + conversion parts that doesn't seem all that appealing either. You can blow up about 10 T5's for that price.

For an all out stupid fast drag car you probably want a TH350 or TH400 automatic. For a stupid fast street car that runs 10s on weekends, maybe you want a TKO or a T56 and can justify the cost. For a stock L98 with afr heads and a mild cam, or a high 11 second vette like mine, a T5 is more economical. I wouldn't spend a dime building one though. Just put a used one in, and put a spare under your workbench if you miss third one day

I need to clarify my point on the uselessness of the 6th gear comment. In my (and many others) application, with a
larger cam the final drive in 6th gear is soooo high (lower numeric) that we can't keep in the cams power band.
On a stock car the 6 speed is great, but you can't cruise at 1900 rpms with a 230+ degree camshaft.

-- Joe

 

I see what you are saying about the investment thing but thirdgens are increasing in value. These cars are finally getting some respect as there are a lot of abused cars out there which raises the value of the ones that are in good shape. This is also starting to go on with the lt1 camaros and the c4 corvettes too.

My friend is not into drag racing all that much though. He mostly has fun on the street and does some auto cross stuff everyonce in a while.

 

They are? From whom? Where I live they're sinking like a rock like everything else. Popularity is at an all time low.

I think your friend will be just fine with the stock T5.

-- Joe

 

I have a beefed up G-force T5 as well. I bought this for myself though, and not for the car.

If you are really hard on cars, buy it. Because the selling price of these cars is not high, put your stock T5 back in when it's time to sell.

These are just opinions from a mechanic who likes to work on his stuff. I would not buy any of the high dollar speed parts with the intention of selling them on a car. They are for my enjoyment and do go from car to car as I change what I am driving.

Just a little different perspective...

 

Ha yeah my friend and I are the same way. I like these cars because they are fun and relatively cheap to modify. It just depends on how much money my friend wants to spend on his trans. From talking to him yesterday he is leaning towards a g-force t-5 now. What brand of clutch are you guys using on your tranny's?

 

Fort worth clutch.. The 10.5" version. You can run the 10.75" version but they say the pressure plate is not as good because it's notched to clear the bolt heads.

-- Joe

 

There's a huge thread in the Aftermarket Product Review (or Vendor Review?) about the G-Force T5's. Check it out.

 

never forget,

the T5 is weaker than a t56

BUUUT

it is also much lighter and smaller than a t56!! and you can throw it on your existing crossmember, re-use your driveshaft and so on!

I'm going to convert my 91 L98 to T5 as well....

I talked to a guy here in switzerland you professionally builds cobras (chassis everything)...he only uses T5's...on 500hp Cobras. ok the cobra weights a lot less than a camaro...but its still 500hp...

you should be fine with a mild 350 as long as you use the clutch and shift properly! like anesthes said before