Basically i have two choses for my build. 1) a stock but very good shape t5 with stage 2 centerforce clutch, or 2) a aod wtih a shift kit and a 3000 stall. both are in very good shape the aod came out of a station wagon with a 5.8 and the tow package so it might have more clutches. i dont know. i would rather have the fun of the t5 over the quickness of the aod in the quarter BUT i dont want to run my t5 and just break it in a couple of months. so i wanted to see what you guys are running and how it is holding up. how do you like it and what kind of engine, power, traction do you have? thanks for any repleys.

 

On my third one ( one was a 4cyl. t-5) switching to a mmr tko-900 over winter. I've never had it dynoed but I'm running 12#s on a stock long block with just an intake man. Estimating just under 500hp and most likely over 500trq. I always seem to destroy third. I'm running a spec. stg 3 with the lightweight press. plate option. But I'd take a t-5 over a stock aod anyday. Hope that helps.

 

what kind of power are you making? how fast do they go? any bro with lag? thanks

 

updated first post.

 

thanks i really would rather run the t5 but i dont want to needlessly break it. sounds like i will though because i want to build something very similar to yours. damn that sucks. is there a stronger 3rd gear i could get? thanks

 

Yeah but its inside a different case (i.e. tko,t56,gforce,astro a5,) LOL It could last for a long time, but I never granny shift. Its also not just third, the case itself is weak, input shaft, cluster shaft, 2nd gear and 3rd gear which are their weakness.

 

I believe longevity of the T5 is only limited to your setup and driving habits. Big hp and torque ie. 500-600 won't necessarily be the demise of the transmission. People have trashed their T5s with bone stock setup. It's a matter of abuse or sometimes a lack of skill. For example, if you powershift a lot in second and third gear something will eventually break. If you are good at it, it will last a bit longer, but same result. Same for lower gears ie. 373s over say 308s. The faster you spin drive components, the more stress they endure blablabla. Slicks will give a quicker hit of traction than drag radials, but at the expense of stressing the drivetrain. You can be fast without going all out. You can be quick if you got the chee$$y to replace the breakage...

 

Not in my experience (unless by setup you mean how much power). Mine broke at around 14psi in 3rd. Not powershifting just too much torque. It's only rated to about 300 lb-ft and 3rd gear seems to be the week point. http://www.moderndriveline.com/Technical_Bits/transmission_spec.htm


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I would say forget the T5, it's on borrowed time once you are past about 7-10 psi.

 

If you have it, drive it till it breaks then upgrade. The cool thing is that they are cheap, dime a dozen and you can swap a broken one in a couple hours. If you have the cash for a tko setup now buy it and save the heartache. Fix it now or later, your choice. But it could last awhile. :noidea:

 

According to Tremec's website they are rated up to 300 ft-lbs of torque......in a 5500 lb vehicle.

There are tricks of the trade that can be done to help them live, but all in all they are pretty much the weak link and are on borrowed time when power levels exceed stock.

Bottom line if you want it to live stock;
Reshim the transmission so it's tight.
No powershifting
Aftermarket shifter with actual shifter stops
A little lighter duty clutch (if the clutch slips a little it'll be less shock on the transmission) i.e. don't run a Spec Stage 5 and expect it to live
Numerically higher rear gear ratio, i.e. 4.10's will be easier on the transmission than 2.73's
Little less traction in the rear end, i.e. if the tires slip a little the transmission won't get shocked as much.


I've read continuously about how the case is weak, but have never read any definitive information about how weak and where it's weak, just a bunch of people that say it's weak. Honestly if it's really weak then you'd think by now someone has figured out where, and the appropriate way, to brace the transmission so it'll handle abuse because as Vader Turbo mentioned, there are lots of these trannies out there.

You can also run G-Force internals as there have been many people that have had great success with those gears, or for about the same price you could pick up a used 3550.

 

:agree: x2

 

Even if you go by Tremec's ratings for the t-5, the highest I can find on their website is 231lbs-ft of torque.

As far as the case goes, it's known to be one of the major weaknesses. Astro performance sells a re-inforcement plate to keep everything straight. There is a decent writeup on it here... http://www.musclemustangfastfords.c...t_1993_ford_svt_cobra_transmission/index.html (they mention the case-cluster re-iinforcement on page 2 shown in the bottom left pic).

 

I think I saw on Corral(or here) someone breaking the case on their T5 near the front. But I don't remember any of the specifics of the event that caused it. I know ANOTHER instant it was possibly a case of something else breaking, and THEN it broke the front of the T5.

 

I broke 2 T5s in my '94 cobra with a pretty much stock longblock and a little 61mm precision turbo on about 10psi.

1st one broke when I was in 5th gear full throttle and 5th gear completely blew out (meaning when I put it in 5th gear it would act as if it was still in neutral, but every other gear worked just fine). That was the stock T5 that came with the '94 cobra and had only something like 60,000 miles on it (the car only made about 190rwhp before the turbo was put on for only about 500 miles when it broke). It sucks going down Rt.50 (65mph speel limit) driving in 4th gear since your 5th gear was gone...it was surely pushing some RPM on that trip home and I felt like someone stole my trans and put a non-overdrive auto trans in it when I wasn't looking!

***Disclaimer, I was not beating on these transmissions (meaning I never powershifted/dropped the clutch on them and the stickiest tire I ever ran was a Nitto Drag Radial (which we all no is barely better than a regular old tire)). Just my experience with TWO T5 transmissions where neither on of the transmissions saw any track time or above 200rwhp before they were introduced to the turbo and then just about immediately shit the bed while being driven on the street and not even at the track.

2nd T5 that broke was a stock T5 out of a '87 GT and that one lasted about just as long when 2ns and 3rd gear starting acting funny and not going in smoothly at all. So I trashed it and put in a T56 and had no problems until the shortblock gave out on me. Then I said fuck it, and built an R-331 stroker w/ a PT76GTS and now have a nice Lentech AOD behind it to see how long this setup will last. Hopefully a little longer than noth of the T5s combined lasted!

 

http://www.ttcautomotive.com/English/products/T-5.asp

Middle of the field for cars, Part number 1352-000-249 and 1352-000-251

Now that is the absolute max for that part number. Even at 231 lb-ft in a 5500 lb vehicle (this is what THEY rate it at) that would mean just roughly over 400 lb-ft in a 3100 pound vehicle.

I'm not saying the T5 is the end all beat all transmission out there, but the availability and the price can't be beat. Like I mentioned above if maintained properly and taken care of they can last for some time (or so I've read). I'll revert back to what Bellman Jeff said about his T5, he said it held up just fine behind his 450 rwhp (roughly) supercharged 5.0, but he kept the input and output shaft tight. He said that they should be inspected after several thousand miles even if new because they will get a little sloppy. I would bet that most people who have broken a T5 never took it out and rebuilt it or reshimmed it prior to beating the ever living shit out of it with double the stock HP and Torque. Again I'm not saying the T5 is the best transmission out there, but if you're careful and can maintain it, it might actually last a little bit.... possibly longer with the G-Force gears.

Thank you for the link, I'll read up on that. I figured that's what their cluster plate was for.



FWIW I'm not trying to start any pissing matches here, I'm just trying to give some thought to a long drawn out idea that everyone just settles on. Plus I've been doing a lot of reading on how to keep a T5 alive as I'm going to run mine with the G-Force internals. I'm not ready to give up on it yet.

 

I'm curious how you converted the load? Also, keep in mind that the stock mustang WC t-5's carried a torque rating of 265 lb-ft up until 1990 when they upped it to 300 lb-ft. This rating I'm assuming is for the stock weight mustang...and is barely if at all even rated for the stock torque levels.

While shimming certanly can help, there is only so far you can shim before you start creating a detrimental interference. Even so, there are those of us who had the proper pre-load and still grenaded the transmission. Hell, all I had to do was roll into 3rd on the freeway and bye bybe it went!

BTW, I don't see any pissing match...just good dialog with different perspectives.

 

5500/3100*231

I don't believe that they would "overrate" the transmission, I figured only Ford would do something like that. Even at that a stock 5.0 is rated at 288 lb-ft of torque, if the transmission was actually rated at 231 or even 265, they would've failed a lot sooner than now. Yes I have "heard" of people breaking them with near stock power levels, but again you have to wonder how the other Mustang owners got theirs to live in the late 80's early 90's.

I agree the gears don't look all that "beefy", which is why I like the G-Force stuff, but I also don't think that without some proper upgrades and care the transmission can't live in "most" instances. Like everything in this world, some parts just hold up better. Not everything is built to last forever, and in some instances some things barely even make it out the door before they destroy themselves. Did your transmission experience case flex or did it just chew the gears apart from too much load?

I'm also wondering if most of the "case flex" idea is coming from people just running a sloppy transmission, that's one of the reasons I mentioned it.

If working as an Engineer and dealing with Manufacturing directly has taught me anything, it's those two points above....not everything will last forever, but hope that they do, and never rate something at it's absolute max otherwise everyone will be on your ass when it doesn't perform. Then again I don't work for the automotive world.

Good, I like sharing ideas without being called a "retard" because I sometimes don't follow conventional thought.

I do have to take a piss now though.


Sorry for all the "quotation" marks.

 

Really, while it may sound right...I don't think you can do a direct relationship between the two.

The t-5's made for Ford are not necessaily the same as those shown the the website. There are different upgrades throughout the years that have beefed up the transmission. The T-5's were barely enough for 99% of mustang drivers. That is, those that have broken them with stock levels are pushing the transmission past the stock torque rating by powershifting...which the transmission's were never meant to take. Oh, fyi...the stock 5.0 is rated at 300 lb-ft of torque all the way up until 93.

I'm assuming it was a combo of both mainshaft flex and transmission case flex. I'll never know however, as the damage is already done.

Sometimes things are overengeneered while others their under. If the transmission doesn't fail when used as dictated by the manufacturer...then really the rating doesn't mean squat.

Your forgiven.

 

i dont know how you guys think a t5 could last with a turbo car, but it wont. mine only lasted a few months with gforce internals in it. the case was not even savagable either. it broke the entire inputshaft area where it was held in place by the billet retainer. the trans never acted up never a shifting issue, it just took a huge dump while accelorating in 2nd gear. just leaned into the pedal and BOOM that was all she wrote. get a tko while you can still sell the good t5 not broken, cuz it will break. not a matter of if, but when. fwiw i never power/speed or banged a gear in this thing. that maybe why it lasted as long as it did? also a heavy clutch(spec or similar) will destroy the input shaft quicker as well.

 

The first t5 in my car broke within 100 miles of upgrading the hp from 350 to 420 rwhp. The 2nd t5 was a gforce and has lasted 5000 miles with 570 rwhp/600 rwtq until last week. I rolled into full throttle in 3rd and it snapped. I loved the way it shifted. I'm going to be installing a lentech aod simply because I plan on turning up the boost.