Converting from T5 to Tremec

[relaxinrob]

I have a 302 in my cobra that puts out 243 hp at the rear wheels and 259 ft. lbs of torque. This winter I plan to install a Vortec supercharger that will boost the hp and torque numbers up around 400. My concern is that once I do that, I don't think that my T5 is going to handle this. So, I am considering making the switch to the Tremec TKO. Has anyone done this? Does anything cross-over.... ie clutch, bellhousing, driveshaft?

Need some advice from someone a lot more knowledgable on this subject than myself.

Thanks in advance for any help.

Rob Burton

[relaxinrob]

Come on guys.......I really do need your advice!!!

[Jim Downard]

O.K. Rob,
I did the same thing a few years ago when I swithed my T-5 for a 3550 tremec. All I needed was the transmission and a new bellhousing. The clutch fork, throwout bearing, and driveshaft yoke all worked on the new tranny. I bought my stuff from D&D in Michigan. They are a Ford racing group. Phone number is 248-926-6220. At least it was a few years ago. That's about all the help I can give you.
Jim Downard

[relaxinrob]

Jim,
Thanks for the information. Is the 3550 the same setup as the TKO? Someone said that I may need a diiferent clutch and yoke for the front of the driveshaft since the splines are supposedly different on each end of the tranny. Sounds like the 3550 would be and easier switch since in sounds like the splines are the same, just a different bellhousing.

Can anyone else shed any light on this?

Thanks,

Rob

[Jack21]

I'll make a case for the T-5.

First off, don't confuse the early T-5's (rated for 260 f/p tq) with the late T-5Z (rated for 330 f/p tq).

Second, close ratio T-5Z's were not installed by Ford in any Mustangs so upgrading or new purchase is necessary.

So far, 15,000 miles on T-5Z filled with Moble 1 synthetic ATF behind stout 351W, and no problems. I love the way this trans shifts.

A lightweight Cobra will spin the tires before putting enough torque through the drivetrain to damage the trans. The one problem with the T-5 is the shifter forks. The shifter MUST be a positive stop design which the stock one isn't, and aftermarket ones (Hurst, etc.) are.

[stangman393]

Which Tremec were you going with? the TKO or 3550? The Tko uses a I beleive 22 tooth input shaft and different output. The TKO would come with the required yoke for the output. You would need to change the bellhousing to a SROD 4speed bell from a 79-82 Mustang 5.0 or aftermarket. The clutch disc has to be changed to match the input shaft spline count. These are readily available as this is the Chevy style.


Jeff

[CC5S]

Dear relaxinrob

Just thought I would jump in to give you a few specs on the new TKO's. The new Tremec's go by the lable of TKO 500 (500 ft/lb), TKO 600 (600 ft/lb), TKO 600 road race (600 ft/lb) all three are 5-Speeds.

Here are the gears for the TKO 500/600/600rr, you will need to factory these gears in for how you are going to drive it and also for the the type of rear gears you are going to run it with.

TKO 500: 1st = 3.27, 2nd = 1.98, 3rd = 1.34, 4th = 1.0, 5th = .68
TKO 600: 1st = 2.87, 2nd = 1.98, 3rd = 1.34, 4th = 1.0, 5th = .64
TKO 600 (road race): 1st = 2.87, 2nd = 1.98, 3rd = 1.34, 4th = 1.0, 5th .82

Here's a link that will give you more details:

http://www.classicchevy5speed.com/tr...nd_pricing.htm

You will find Ford part #'s on this site. We also have a lot of info and stock of chevy/ford AFR Heads.

http://www.classicchevyheads.com

Hope the info helps you out, good luck.

[klayfish]

Rob,
The set up you're planning is sounding a lot like the Mustang road racer I just bought. 302 w/Vortech, roller rockers, MSD, injectors.... with a Tremec 3550. See my recent post about problems with my Tremec. The car flat refused to downshift into second gear. I've been doing research and found that this is apparently a very common problem, as are a few other things. Someone pointed me to a local trans expert here in PA, probably fairly close to you. All he does is rebuild T5s, Tremecs and T45s. The technical nitty gritty got beyond my understanding, but he said the 3550 uses brass parts (some kind of rings or separaters), which aren't very strong. This can cause the shifting problems I'm having. He said the gears are real beefy and can really handle abuse and power, but some of the other stuff isn't the greatest. I discovered that if I push my shifter firmly towards first gear then pull down into second, it'll work. But it's not the best solution. To be fair, I do have a Hurst shifter on there, which may be the problem. You should check more on the Tremecs before you get one. Or maybe look for a rebuilt one that has the better parts in it (he said he could rebuild mine with the stronger parts for around $500).

Steve

[Wade Chamberlain]

thousands of mustang, cobra, camaro, etc, owners out there that are happy w/ their tremecs!

Steve - you have a USED trans, with no knowledge of it's previous treatment, and you don't even know if the problem is with the trans itself! Yet you're condemning Tremecs? Could be clutch, could be shifter, could be wrong lube, etc.

[Jim Downard]

Rob,
Some more information I forgot to add. My old t-5 started jumping out of second gear during downshifts with a rather loud bang. I just figured my 351 overdid the t-5. Anyway, the tremec is still going strong with about 425hp and 400 ft. lbs torque in front of it and I'm not experiencing any shifting problems. The guys at D&D answered all my questions. By the way, I've spoken to quite a few guys on shifters and I keep hearing the Pro 5.0 is the good one. I don't know, but it's what I've got and it works so take that info for what it's worth.

Jim

[klayfish]

Wade,
I'm not condeming the Tremec at all. In fact, I am happy to have it, in that once I figure out what the problem with mine is I'll be thrilled knowing I've got a strong beefy trans that can withstand the use it'll get. My car shifts perfectly fine, like butta, in all gears, except the downshift into second. And I did say in my post that I had a shifter that may be the problem. It could also be the clutch or something else. I wasn't at all recommending not to use it. I don't know enough about them to have a valid opinion one way or the other. I've only had my car for a week. I'm just passing along the info I found in my research after I came across my problem. The expert I talked to said that the rebuild kits for the 3550 get rid of the problem and make it really strong.

Steve

[CC5S]

Wade,

I will also add to your positive comments about Tremec. Over the past few months we have sold 60+ Tremec TKO 500 & 600's and have not had a compliant about the tranny, shifting issue, ect..
Some of our clients are running/shifting these hard on the 1/4 mile track and pushing 600+ ft/lb torque.

Shifter Note:
The standard shifter that comes with the TKO is very tight and shifts very well. The 2" offset made by Tremec is also tight but is a little tall and people need to be aware of potential tunnel issues if they need the 2" offset. Other companies are making 2" offset shifter that are shorter but they are still trying to workout the kinks.

[LewisPayne]

was not so bad to do, bell housing is a big part , go to a ford dealer parts department ask for a Motorsport catalog, it is all there; don't buy from them go to a performance shop like Brothers or Summit much better price. )

[goaztecs]

Another case for the T-5:

Will and Bruce from Modern Driveline run a business that does NOTHING BUT sell and service T-5's and Tremecs. They have run a Z-spec T-5 in their '92 fox mustang race car for 6 years. The car puts 486hp to the rear wheels!! So far, the Z-spec has held up without incident. One trick is to use a 100% kevlar clutch, which eases the torque transfer to the trans gears.

Also - an important note about Torque. It is a force, so you can only put your peak torque through your transmission gears with a sufficient opposing force. This is accomplished on a dyno with an engine brake or a viscous damper of some kind. In a light bodied Cobra you will never put your engines peak torque through the drivetrain without breaking the tires loose. You simply cannot make enough opposing friction.

[Cobra75]

Rob,
How much do you want to spend?
T5Z-$1100, 3550=$1560, TKO=$1580

I have a TKO in the Shelby (434 RWTQ) and have had it since '98 with no problems. Shifts are notchier than the T5Z I have in my 302 Mustang (276 RWTQ)

I would hope that the 3550 & TKOs are going to sell cheaper now since the new T500 & 600s are out, and you might find a bargain.

The 3550 & TKOs have the same exterior dimensions, but the input & output shafts are different. The TKO @425 lbs-ft, is the stronger rated box, but requires a 26 spline clutch disk and 31 spline yoke. The 3550 rated @350 lbs-ft has a 10 spline input and 28 spline output (same as the T5) The 3550/TKO are about 0.62" shorter than the T5.

There are also Road Race versions of the 3550 (@375 lbs-ft) and TKO (@475 lbs-ft). These have different 1st and reverse gear ratios but they are even more $$.

If you stick with a T5Z (330 lbs-ft), you won't have to change your yoke and driveshaft.

If you go with the 3550 or TKO, you'll have to change the bellhousing. I would get the FRPP steel bellhousing M6372-C ($285 list). This includes the block plate and fasteners and uses the Mustang clutch cable. This BH will also fit the T5Z.

Personally, I stick with your old T5 until it blows up.

[coosawjack]

Rob...

I've had a T-5Z behind my 408W stroker for two years now and no problems!! The lack of traction will save you any torque damage.....provided you don't miss third and break a shift fork!!

Get an aftermarket shifter and "forgedaboudit"....buy a 3550 or TKO after you break your T-5....if you ever do!!

coosawjack

[relaxinrob]

Thanks Jack,
I am gong to go with the T5Z for many reasons, but most importantly, I believe that it will hold up. I am going to put the B&M shifter on it with the positive stops.

Thanks to all that have contributed to this thread.

Rob