I will soon need to change my Bird's clutch, plus the master and slave cylinders. It's a Luk performance set, but it won't hold the engine's torque in the higher gears any more, after the latest upgrade I did.

Since I'm looking at 400-500 bucks for a clutch upgrade (ALL the parts), this is decision time, and I am asking for your opinions, hopefully based on your own hard experiences.

Simple basics: When running E85, my engine is making 420 horses. But more importantly, it's making +/- 530 ft-lbs from off-idle to 3000 rpm. It falls to 450 ft-lbs at about 4500.

Due to economics, my choices are:

• Upgrade the clutch for about $500, keep my WC T5, and hope it doesn't break.
• Build a replacement 700-R4 for about $600.

It seems strange to me that I can build, install, and re-tune for a 625+ ft-lb automatic, for less than half the cost of a gear set and case brace upgrade for my T5 (over $1300, last I checked; plus the clutch). But that's reality.
A T-56 is not an option. Again... cost. Them things, plus the mods needed to put one in, is pricey!

I don't go to the drag strip any more, but I do love to punch it out on the road. I don't race, but I will often downshift to 3rd for full-throttle passing. I have never power-shifted this transmission. Presently, it's running great and shows no sign of problems.

I have read in magazines of stock T5's living for years making 11-second passes (usually in Mustangs), so long as they were never power-shifted. I have also read of T5's going up like a grenade on the 3-4 shift, even without power-shifting.

Ultimately, I don't care if I have manual or automatic. If I build an auto, it will have a manual-shift option, so I'd still have the fun factor.

So I am asking the best sources I know:

• Am I running this transmission on borrowed time?
• Is it more a matter of "when" it will blow up, rather than "if" it will blow up?
• Might it blow just when I stomp the gas in 4th gear one day?

 

first of all there is no fun factor in any automatic transmission

i make around 450 in my camaro i had the t5, replaced it for a tremec tko 600 nothing was wrong with it, just didnt feel like having gears go through me when it exploded, but i run drag radials and beat the living snot out of my car.

it's anyone's guess if and when it will go...

 

Well, I did ask for opinions.

And there's the difference. I'll never put drag tires on it, and likely will never go to the strip again, even for test & tune. Even with the posi rear, the tires have no problem breaking loose when I stomp it, which has to be good for the tranny. Last trip to the strip, I had a lot of trouble getting a good hook-up. I can testify, though, that smokin'em well past the 100 foot line is a crowd-pleaser, even if it ruins your ET.

 

I asked roughly this same question and couldn't find an experienced answer from anyone that had an upgraded case and gearset. Only got mixed opinions of people with stock units.

 

That's what I'm looking for. Experiences good and bad with a stock T5 bolted to big torque.

I do know that a stock T5 on a setup like mine, with drag slicks and hard launches, WILL blow up. But mine will never have drag tires installed, and I don't go to the strip any more.

I know that I can upgrade the gear set and beef up the case to take the power I've got. For about $1300+.

 

Hey SR-71,

Always envied your drivetrain combo.

Have a 400 sbc waiting in the garage to replace the pitiful L03 in front of my T5.

Even replacing or beefing-up the T5's with a T56 or Tremec, there's still the glorified Vega rear end to contend with.

Although,..... stockish size tires could function as the "fuse" to protect these fragile T5's.

Unfortunately, it seems big bucks have to be spent to equal the drivetrain reliability of even a factory stock 1st or 2nd gen Z28.

It's a shame the 80's GM bean counters basically required the redesigned F bodies to be even more "disposable" than previous series.

Tony at Astro Performance in Fla. seems legit with GM WCT5 upgrades.

Let us know how your improvements work out.

 

Hey SR-71,

Always envied your drivetrain combo.

Have a 400 sbc waiting in the garage to replace the pitiful L03 in front of my T5.

Even replacing or beefing-up the T5's with a T56 or Tremec, there's still the glorified Vega rear end to contend with.

Although,..... stockish size tires could function as the "fuse" to protect these fragile T5's.

Unfortunately, it seems big bucks have to be spent to equal the drivetrain reliability of even a factory stock 1st or 2nd gen Z28.

It's a shame the 80's GM bean counters basically required the redesigned F bodies to be even more "disposable" than previous series.

Tony at Astro Performance in Fla. seems legit with GM WCT5 upgrades.

Let us know how your improvements work out.

 

As for the 10-bolt rear-- I know (or I'm quite certain) that a 10-bolt, properly maintained, can handle my torque, so long as I don't put slicks on it and do hard launches at the strip. Rear axles break on launch, because that is when they experience the greatest torque forces. Since my 406 easily breaks the tires loose with throttle only, even in 3rd, I'm not too concerned about breaking the rear end. The tires simply won't hold traction on a hard launch. Good for the rear end, and impresses by-standers on the street who don't know any better.

But transmissions break on the upper gear shifts. Gear reduction softens the blow, so the low gears just transfer torque out, but higher gears take the brunt of it. On mine, the tires won't break loose in 4th without a clutch dump or power shift, neither of which I do on the street.

I figure the 80's bean counters didn't have any thought that computer controls would let them bring back horsepower, so they didn't worry about it much.

I've got an e-mail in to Tony at Astro, asking his opinion on this same question. Haven't heard back from him yet.

I'm basically struggling with the cost question. Do I just upgrade my clutch for about 500, or build an automatic for about 600? Because if I choose to just upgrade the clutch, then the transmission breaks later, it will cost a whole lot more in the end.

 

I know a guy, (yes I know the same old I know a guy deal) who had an Iroc. He put a 383 in front of the factory T5. Now when I was working with him we got to talking and I asked him about putting a 350 or bigger in front of a T5. He told me straight off, do not do it. His story was he went through 3 or 4 T5 WC trannys each one grenading within 6 months. Told me, go straight to the JY and get a T56. Otherwise I might be doomed to the same thing.

I met another guy with an 84 Z28 with a T5 and built 350. He been running that combo for years with no issues. I guess it comes down to torque. The 383 is a known torque monster when built right. 406s even more so. I guess it comes down to luck. I didn't want to play the game and got a T56. I would say if you can afford to, then run the T5 til it blows after replacing the clutch. The fact that you don't run slicks, puts it in your favor.

I'd say do whatever you want, replacing the clutch or swapping requires trans removal regardless. But keeping the manual saves the headache of the shifter and wiring etc. You are right, it will cost more in the long run if you break it after you upgrade.

 

I've had the same t-5 and centerforce clutch in my 92 for 10 years without issue. Its making somewhere (sorry my dyno sheets aren't in front of me) north of 370 ft-lbs. at the rear wheels from 2000rpmish to 3500rpmish. My only catch is i haven't done burn outs or anything drag race related since this combination went in. I still beat on it a bit but nothing extreme. Could I break the t-5 with this?...sure. Will I?....probably not.

 

Did they say how they drove it? Was the 383 guy using it regularly at the strip?

I actually suspect that it comes down to how it's used. I read an article from a Ford performance magazine claiming a car with a stock T5, slicks mounted, had been making multiple 11-second passes for six years, with no problems. They claimed the key was in how it was shifted, and they avoided power shifts. (Can't find that article right now.)

Car Craft mag said "The bottom line on production-based T5s is that as long as you don't ham-fist the box with repeated power shifts, it will probably live a long and useful life." Article here.

I'm just trying to find some first-hand confirmation from "normal" street use.

This is what I'm looking for. While your torque numbers aren't as big as mine, yet you are driving the car on the street in a somewhat "normal" fashion. I will definitely consider your first-hand experience input. Thanks.

 

350 guy was definitely not tracking it, drove it spiritedly but never took it to the strip. The 383 guy was more of a hot rodder (he daily drove a rat rod for a bit). Considering he also has a 30K mile 88 GTA that is pristine, he know show to take care of his cars. I don't know for certain if he took that 383 car to the strip. But I know he drove it pretty hard. He builds stuff and drives it like they are meant to be.

If I find some first hand stuff I will let you know. Reason why I didn't try it was I didn't trust the NWC T5 with the power I had in mind. And I got a killer deal on a T56. Best of Luck. If you are going for longevity though, with the least amount of possible problems I would just switch to the auto and be done with it. No sense in trying to run the T5 if you're uncertain about it.

 

I've had a non-WC behind my 350/330 for a number of years without issue--with typical daily driving.

JamesC

 

sr, if your anything like me these questions your asking are because unsure and there is doubt... so i just eliminated that with a tremec tko...

now i dont worry.

i blew my 10 bolt, 8 teeth off the ring gear with the t5 and drag radials, this was burnouts on the streets, replaced it with a 12 bolt..

if your not putting sticky tires on it, the t5 will probably hold... again who knows. but i eliminated the doubt.

 

Well, I got an excellent answer back from Tony at Astro Performance. He definitely knows his stuff, and he took the time to explain things. Great service. He describes their "A-5 Upgrade:"
Again, OUCH!
Even though I plan never to install slicks or drag radials, the shaft upgrade is probably a good idea.
Shifts well - Check!
Optimal clutch release - Check!
Low clamp load - Nope.
No aggressive tires - Check!

Clamp load is the killer. I already know 've got to have a much more aggressive clutch. That means higher clamp load along with at least a dual-compound disc. That pretty much kills the equation. My clutch needs pretty much match what he recommends for their A-5 upgrade. So what will the clutch upgrade on a stock T-5 do? Probably go bang!

I'll have to crunch numbers and assess risk. In addition to the approx. $2100, I have to add a new clutch fork, pivot ball, release bearing, slave cylinder, and master cylinder. They are all pretty much worn out.

So now, on the surface, it looks like an automatic build and swap may be the winner.

 

I would just run the T5 til it blows and save for a T56. Or just buy another T5 and keep it as a spare. T5's are so cheap, and automatics are so boring... that there's no way I would consider it. Even a full manual valve body auto is going to lack that mechanically locked feeling a manual trans gives you. It still has to go through a torque converter.

 

I was going to say, my T56 swap is so far only...1200 in; including the trans. I still need to get the clutch and flywheel, but even then I'm probably only 1600-1700 into my swap. I scored my T56 on these boards, for 700 and that included everything except one or two minor easy to get items, I am replacing the clutch and flywheel because it made sense to start new, even though they were included with the trans buy. But that is only if you really care whether its a manual or auto trans. Since you said you don't care, if you want an auto go for it.