1999 T56 on a 1995 LT1?

[shadowbane]

This is my first post and topic here on HybridZ, and most of my time has been spent reading. I'm located in Lafayette, CA (East Bay, on the other side of the tunnel from Oakland) and I'm in the middle of a 1975 280Z conversion with a 1995 Lt1 and T-56. R200 in back.

 

I have a 1993 T56, but have read in the JTR manual that 1994-1997 transmissions have more appropriate gear ratios (to be compatible with the rear diff). I have found a 1999 T56 on craigslist for the price I got mine for ($600) but am unsure whether this tranny meant for the LS1 will have a compatible bolt pattern to mate with the LT1.

 

Since the transmissions are from different years and engines, will there be any computer related problems? There may be none, but I am still trying to wrap my mind around the electrical portion of this project (need to GET a wiring harness for the engine still, so points of reference are limited).

 

Has anyone else used a 1993 T56 in their conversion? How'd it go?

 

Thanks for all the help!

Ramsey

[jbc3]

In 93 there were 2 6 speed trannys. M-28 and the M29. They will both fit the 95 LT1. The 99 will not. The LS1 transmissions have a different front plate, the input shaft is longer and the clutch TOB is different.

The gears on the M28 are 336-207-135-1-.8-.62 1-2 is a big drop

The gears on the M29 are 297-207-143-1-.8-.62 These are nice.

The 94-97 M6 gears are 266-178-130-1-.74-.5

The 94-97 transmissions are supposed to hold up to more torque than the earlier models. I personally would like to have the M29, if it were stronger, I like the .8-.62 OD.

 

 

Jody

[Danno74Z]

Ramsey,

 

To my knowledge the T56 from 1994 - 1997 years were the same and are the one you want to use if you can. The 1999 is for the LS1 engine and will not bolt up to the LT1 engine. GM does produce an aftermarket T56 but you will have to purchase a bell housing to make it work. I think you will be fine with either the 1993 or 1994-1997 but most people use the 1994-1997.

 

1994-1997 T56

First 2.66:1, Second 1.78:1, Third 1.30:1, Forth 1.00:1, Fifth 0.74:1,

Sixth .50:1, Reverse 3.28:1

 

Design Torque Rating: 450 lb-ft

Approximate Dry Weight: 125 lbs.

 

1993 T56:

First 2.97:1, Second 2.07:1, Third 1.43:1, Forth 1.00:1, Fifth 0.80:1,

Sixth 0.62:1, Reverse 3.28:1

 

Design Torque Rating: 400 lb-ft

Approximate Dry Weight: 125 lbs.

[shadowbane]

Thanks for the replies jbc3 and Danno, the differences between the M28 and M29 are really helpful, and I will check which version I have. Just to note, I will keep my LT1 motor bone stock (freshly rebuilt) as the car is being assembled more for fun around town and as a daily driver rather than a high hp beast.

 

I suppose I will stick with my 1993 T56 either way, as long as it is compatible, and possibly change it out later if I can find a 1994-1997 for a reasonable price.

 

Any other questions will hopefully be answered by searching, (I bet this one could have been with enough patience) but I'm sure I will need to make another topic eventually.

 

Take care,

Ramsey

[shadowbane]

I'm unsure whether I should just edit my old post or make a double... but new info has been gathered. After examining the tags on my transmission, and called a local GM dealer, it turns out the box is actually from a 1994-1997 (yipee!).

 

I have a centerforce clutch kit, and still need to get a slave cylinder, and bearings, but am having a tough time finding a clutch fork/lever (actuated by the slave cylinder). The dealer pricing is $104 + shipping...

 

http://www.safepay.net/cgi-bin/shop/cart.cgi?db=mddata.txt&category=bellhousing&merchant=moderndriveline

They have one to fit the 94-04 T56, and I will just disregard the Ford logo, but is a clutch lever cover required/recommended? It would bring the total price up to that of the dealer.

 

Thanks for all the help. I really appreciate the info even after this topic has been covered (some searching after this thread's creation revealed individuals in the same pickle as I)

[Danno74Z]

shadowbane

 

Just remember the T56 out of a Camaro (1993-1997) is a pull type clutch assembly with a fork and integrated throwout bearing. It also has a special flywheel for this engine. This is a completely different setup then the push type clutch you are probably familiar with - Caution. 1998 and on went to a hydraulic throwout bearing setup which did away with the fork setup. To make your setup work (your current transmission) as a push type clutch you need a special bellhousing. The T56 transmission offered by GM as an aftermarket replacement for a T5 one could use a stock bellhousing but something about the T5 has a 22 degree angle to it or something. All I can tell you is be very careful so you don't purchase parts that won't work.

 

Danno74Z

[shadowbane]

I already have the appropriate bell housing, which I should have mentioned in the original post.

 

I've secured an appropriate flywheel as well.

 

OK, so, parts that I would need are a pilot & release bearings, a T5 or T56 slave cylinder, slave cylinder extension piece, clutch fork, fork t-stud, inspection cover, and a clutch alignment tool.

 

If that all looks good I will start'a purchasin'. I just want to get everything situated inside the bell housing/transmission before it goes in, and do the slave cylinder stuff later (like it should be done!).

[Danno74Z]

shadowbane,

 

When you say you have the appropriate bellhousing which one are you using? The original one that came with the T56 or an aftermarket unit? Are you sure the fork you quoted for $104 will work with the LT1 AND T56. Ford did use the T56 tranny on their cars but not in the same way GM did on the Camaro. Some members here used the method suggested by JTR to hook up everything and I would suggest you read that section of the book if you haven't already. I would use the GM slave cylinder and use an aftermarket master cylinder as the GM unit would be real hard to retro-fit in a Datsun. GM sells the slave and master cylinder as one unit and to my knowledge you can't buy separately. You might be able to buy the parts separately at NAPA.

 

Danno74Z

[shadowbane]

Danno,

 

I have the original, Borg Warner produced bellhousing.

I just verified that my flywheel is correct for this application.

 

I cannot say for sure whether the fork quoted by the dealer will work with the LT1, but even if it did, $104 is way too much to pay for a friggin' fork.

 

So, if I am using the stock bellhousing (I feel so stupid for asking these questions, but I've been looking and looking on the internet, and no one addresses this issue), what exactly will I need? Has anyone purchased the fork assembly from a supplier other than a dealership? I may need to resort to wrecking yards.

 

Am I wrong in assuming this: http://store.summitracing.com/partdetail.asp?autofilter=1&part=CNS%2DSC126869&N=700+4294908216+4294908022+115&autoview=sku would work in my application?

Here is another option: http://replacement.autopartswarehouse.com/parts/autopartswarehouse/wizard.jsp?year=1995&make=CV&model=CAMA-Z28-002&category=All&part=Clutch%20Slave%20Cylinder&dp=true

From what I have gathered, either will work.

The release bearing can be this one: http://replacement.autopartswarehouse.com/parts/autopartswarehouse/wizard.jsp?year=1995&make=CV&model=CAMA-Z28-002&category=All&part=Release%20Bearing&dp=true

And the pilot bearing can be this one:

http://www.autopartswarehouse.com/performance/brand.php?makeid=5&modelid=30&year=1995&partid=397

 

If the slave cylinders between the T5 and the T56 are interchangeable, are the forks too? It does not seem like it from your earlier post Danno, but i can't help but ask. Those ford forks are everywhere on ebay.

 

So my last problem is getting the clutch fork, fork t-stud, inspection cover, and a clutch alignment tool.

 

If there is something I am completely missing here... well metaphorically slap me. Those slave cylinders were not marked as being "pull type" but as far as I can tell they will fit.

 

Once I get this squared away, it will facilitate mating the transmission with the engine prior to installation.

 

Thanks,

Ramsey