How much is a NOS 6 speed worth nowadays? Those that have converted over happy with the results? Just wondering on kinda the PIA factor VS Gains/benefits. Would ya do it again? Thanks for opinions!

 

$1500 + clutch/FW parts

Pros:
Holds 500+ HP/TQ
Sometimes described as "bulletproof"
When hydraulics are good, smooth working unit

Cons:
DMF's have been discontinued (a few are still available @ $1k-$1.2k)
SMF's are noisy in this unit (if DMF is not used)
Lot's of slave's have seal installed backwards

See ZFDoc.com for more FAQ

 

Thanks for the input Gregg. I havent really gotten into the tech side of change over but was interested in the opinions of those that have changed over. I guess noise isnt a real factor, the 4+3 unit sounds like a bunch of rocks in it when clutch isnt depressed. Any SMF folks got any input on how noisy their ZF is?

I like the 4+3 well enough but hate the switch and forgetting to turn the OD off. I figure if I am clutching for the OD to engage, I might as well have the shift too.

Just the brain wandering!

 

If you have the 4+3, there are better options then the ZF6, do a search on Central Coaster, he did a complete write up on installing a T-5 into an early C4. Also check out LD85's post on installing a Keiser tranny into his '85.
BTW, I know what you mean about the 4+3, the easiest thing to do is sell the car and buy a 6 speed; that's what I did.

Randy

 

Randy, thanks for the input. A T5 is an option altho not a good one IMHO. It was installed in 305 F bodies and 6 cylinder Jeeps, vehicles with less HP and torque. Modding the T5 will be harder than the ZF as all the parts for the ZF are stock Corvette.

The Keisler is a better but much more expensive option. I can save $1000-1500 by going ZF. One article I searched, the guy rvrn used his original 4+3 SM flywheel. That leaves a new clutch disc and PP, hydraulics, yoke and a new BH. Modding the tunnel shouldnt be a big deal.

I am looking for input from folks that have done this particular swap. Are you happy with the swap and if presented the same circumstances, would ya do it again or go with a T5 or Keisler?

Thanks again guys!

 

Just an FYI, you can have any chip tuner turn off the auto-ON function of the 4+3 and you can then turn it on when you want it. Made the car a million times more enjoyable to not have to worry about it kicking in once it got warm. Now I just click it on when I want to get the MPGs up. (This is on an 86, there might be slight variances with other years and control styles.)

Also, as for the T5, you might want to make sure you get a world class T5, I guess the standards were sort of weak... ?

 

The T5 CAN hold up if not beaten on in a retarded fashion. I had one beind a 320 hp, sbc 400. Obviously, that engine had a lot of low RPM tq. I ran that car for years, at the strip, two nights a week. I flat foot/powershifted every shift, every pass. I kept the clutch fluid clean, ran a decent clutch (Centerforce Stage II), changed trans fluid regularly, and used a shifter w/adjustable shift stops. The trans held up for years, as I said, and I sold the car, tranny still working perfectly.

I'm not saying that the OP should use the T5....but just that he shouldn't dismiss it.

Benfits are;
*Cheap/easy to get/and parts are cheap
*Quiet
*Smooth shifting
*LIGHT WEIGHT; weighs about 50 lbs.; much lighter than the other options, which is nice for the car's curb weight, and also for removal/installs. Do it by hand...easily.

 

Most of us former ford guys all pulled the POS T5's out of our mustangs and threw them in the trash, Replacing it with a Tremec-3550 or TKO.

But hey , maybe they used a wimpier version of the T5 in that ford stuff.

 

This is why I put a ? behind that statement, all I have heard is stories of failure or success. Seems like if you are buying a T5 though why wouldn't you buy a WC T5? Is the cost even that different?

 

I don't know what power the OP has. I'm sure once you get into the 12's or faster, the T5 would start to have regular issues. My car would only run low 13's, but did that for a loooong time. And again, I could have been a retard and gone out and "blowed up my trans"...any time I wanted to, if that was my goal.

The only reason to get a NON WCT5 that I can think of is availablilty (there were way more non WC made than WC) and how you use it. For street use, 300 chp or less, I think any T5 would be fine, driven and cared for decently.

 

Even the World Class T5s were really not that great compared to some aftermarket options. I would take a Tremec any day of the week over any T5.

Here is some info I found on a ford forum (no flames pls :P )

World Class & Non-World Class
There are two basic kinds of T-5's, Non World Class (NWC) and World Class (WC). The first T-5 was non-world class. In 1983 and 84 Ford used the Non-World Class T-5 to improve the Mustangs performance and gas mileage. All the V8 NWC boxes had 2.95 first gear set with .68 overdrive. All the main output shaft gears and 1st, 2nd, 3rd, gears riding on a solid output shaft with deep oil grooves to provide lubrication. The lower counter gears spin on straight cylindrical bearings with a thrust washer in front to provide support when under load. All the synchronizer rings are made of solid bronze which are of different size than those found in a would-class T-5. It is because there is no bearing under each gear and the bronze synchro rings that the NWC use the heavy 70w gear oil. Torque rating for the NWC was 265ft/lbs.

1985, Ford introduced the World Class T-5 installed with 3.35 first gear set with a .68od behind the 5.OL. T-5 was also used behind both the standard 2.3L with a 3.97 first gearset and the SVO Mustang. SVO received a one year only 3.50 first gear ratio as the 3.97 gear ratio was too low for the added power of the turbo charged 2.3L. No longer were 1st, 2nd, and 3rd gears spinning on a solid output shaft as needle bearings were installed under each gear to reduce drag. The lower counter gears saw tapered bearings to replace the bronze thrust washer. All main shaft synchro's were fiber lined steel rings to improve rings friction surface while 5th remains bronze. By improving the surface friction the synchro slows the gear faster making for smoother shifts. The design remained the same until 1989. Torque rating remained the same at 265ft/lbs.

1990 to 1993 the stock Ford production V-8 WC T-5 was upgraded with stronger 3.35 gear set by increasing the nickel content to produce a harder, stronger gear. 2nd and 3rd gear ratios were decreased slightly tp provide more torque to the rear wheels. Synchro linings on 3rd, 4th were improved by changing from fiber linings to carbon fiber to further improve the friction surface resulting in better high rpm shifts. A longer throw shifter was installed to "make shifting easier". The speedo drive gear was changed from 7 tooth to 8 tooth. The 8 tooth was a step backwards when installing lower rear axle ratio greater than 3.55 as the driven gear is limited to 21tooth count. Yes, 23 tooth gears are available but do not last long as the teeth are thin and do not mesh correctly. Torque rating jumped to 300ft/lbs.

When the 93 Cobra was introduced, so was the "Cobra Spec" T-5. It was the first T-5 with a front tapered output bearing and steel front bearing retainer. The Cobra boxes also received a reverse gear brake and synchro assembly where there was none before. Just about everything else remained the same. Torque rating was increased to 310ft/lbs.

1994 and 95 were the last two years Ford used the T-5 behind a V-8. With the introduction of the SN95 Mustangs, the bell housings in both 3.8L and 5.0L were made deeper to place the T-5 shifter in the correct location to the body. This in turn made the input shaft longer. The neutral safety switch was eliminated, as it was no longer needed. The GT 5.0L Mustangs received the standard input shaft bearing and aluminum bearing retainer, where the Cobras continued with the tapered or "cupped bearing" input shaft and steel front bearing retainer. Torque ratings for both remained the same as the 93 T-5 models. 4 cylinder T-5s were no longer needed when the 3.8L V6 motor came along and was replaced with 3.35 first gear ratio and a .68od. The only difference between the 3.8L and standard 5.0L T-5 was the input shaft length. Changing input shaft of the 3.8L T-5 with 93 input shaft, will result in a 93 and early spec T-5. Everything else remained the same.

Today's V-6 Mustangs sports the last of the T-5s. The T-5 behind the 3.8L is a 3.35 first gear set with a .68 over drive. What makes these different from the rest is the electronic speedometer trigger. No longer is there a mechanical driven cable system. It has the longer input shaft equipped with a steel front bearing retainer and reverse synchro brake assembly. Torque rating is 300ft/lbs.

Ford also used the T-5 in 2.3L cars through the years. While the 4 cylinder T-5 may appear to be the same, they are not. Most 4 cylinder T-5s received a 3.97 gear set with a .79 overdrive and small input pilot bearing shaft. Four cylinder T-5's should not be used behind a V-8, even when the pilot bearing id is decreased to match. Simply put, they will not hold up. Torque rating ~240ft/lbs. Besides first gear is much too low to be usable behind a high horse power car.



It all basically amounts to leave the T5s out of a corvette


Here is a link to a corvettefever article where they pull a 4+3 out of a C4 and replace it with a Tremec TKO 600.
http://www.corvettefever.com/techart...ech/index.html

Here are the specs on the TKO 500-600 transmissions:
TKO 500:

* Capable of handling 500 ft/lbs. of torque.
* Available with a standard 10-Spline Input Shaft or heavy duty 26-Spline Input Shaft.
* Gear Ratios:3.27, 1.98, 1.34, 1.1, & .64 O/D.
* Includes a Hurst Billet Shifter.
* Can be used with Mechanical Speed Sensor or Electronic Speed Sensor.

TKO 600:

* Capable of handling 600 ft/lbs. of torque.
* Comes standard with a 26-Spline Input Shaft.
* Gear Ratios:2.87, 1.89, 1.28. 1.1, & .82 or .64 O/D.
* Includes a Hurst Billet Shifter.
* Can be used with Mechanical Speed Sensor or Electronic Speed Sensor.


They run about $2100 for the trans, but hey ........... you will only have to do that job once!

 

I know about all the tq ratings. I'm telling from first hand experience, what they are capable of if treated properly. There is NO DOUBT, that I was putting way more tq through mine than the ratings that you pasted above. 400 CID. I suspect I was pushing over 400 lb-ft. Over 150k miles and countless drag strip passes. Post all the forum quotes you want, I'm simply trying to convey that it's not all the "doom and horror" that many people claim...and that is from first hand experience.

$2100 (for the TKO) is yet another reason to CONSIDER a T5....especially for a street driven car. I got mine for $200.00; I could use 10 of them for "your" price, yet I never even used up one!

 

Thats a big DITTO! I had the T5 (NWC and WC) in my Z28. I went through 5 of them with the last one being the WCT5 which lasted up until the point where I sold the car. It was still holding up fine but I am sure it would have died soon anyway.

 

Wow, what a great bunch of info, fellers. Even if I did decide to go with a T5, I would have to have an expert to decipher which one was which.

The main reason I dont want the T5 is the fabrication factor. While my skills are decent, I lack alot of the proper shop equipment to do extensive conversions. I was considering the ZF because all the parts are available and little modification/fabrication would be needed. The TKO 500 kit is my first choice because it has everything needed and even less mod/fab necessary.

My engine at this point is still basically stock but it is slated for rebuild too this year. Pushing this engine above 300 HP isnt difficult and I should end up with something south of 350 for a final count but you never know. The car will spend its time doing road trips to FL, cruise ins, general duty and hopefully occaisonally spanking my buddy's stock C5. Racing it is definately out as I spend alot of time pulling seat upholstery out of my butt as it is. Its my hobby car, one to take the targa off and cruise around taking in the view while enjoying the 23+ mpg it delivers.

The price of the 6 speed interested me as it would save some over the TKO conversion. The T5 is even cheaper but having to farm out some of the work would put the price back up towards my other two options.. Like the intake swap, I guess I will just save until I have enough for the TKO for the support and warranty.

Thanks again for all the great info, thats what this Forum is all about!

 

Do a search on LD85, Larry has done the swap.

 

And there it is. The perfect candidated for a T5.

I hear you (OP) about the fabrication though. I can't believe that no one has packaged a kit for this. This was the closest thing I found, and I would do it a little differently, myself:
http://members.cisdi.com/~anesthes/f-car-t5/

Anyway, which ever option that you choose, it will probably be better than the 4+3 over all.

 

Tom, thats a great write up on the T5 conversion and the overall price of less than $1500 makes it very attractive. Other than the shifter, there isnt alot of fab work besides some fiberglass patching on the hump. This conversion is at least economical enough to consider, PIA factor being outweighed by the economic aspect. Reusing the clutch, PP, housing and hydraulics saves a bunch of money. I was thinking there would be alot more fab work but the adapter for the cbeam eliminates the worst of it. Doing the driveshaft is something the average guy cant do and balance properly anyway.

Thanks for the great link!

 

Oh yeah, what would you have done differently in the process?

 

This part:
I would use an F-body bell housing to mount the trans "canted" toward the driver, as it does in any F-body car, which would better orient the shifter and eliminate the shifter modification, and weirdish shifter path.

Of course that would mean a custom C beam adapter, but I'd rather fab that, than mess w/the shifter.

Glad you liked the link/read. Certainly, it's an option worth considering, IMO...especially for a street driven car.