85MikeTPI

iTrader: (9)

Since I've found some discussions on the internet about the SSR T56 strength and the hybrid build, I thought I'd set the record straight and have updated the write up with some Appendices.. To summarize:

I'll continue to update the write-up as new info and/or clarifications come in..

BlazinT/A

iTrader: (10)

bump.....any updates? have you tested it out yet?

so it would be in our best interest to find a c6z trans from 06-07 and add the ssr output shaft and modified tail housing as it has the same gearing as our fbody t56?

85MikeTPI

iTrader: (9)

My personal 1000hp T56 is still sitting on the bench. My L92-VVT project is coming along slowly, and I have this 2nd 900hp T56 SSR hybrid version (2pc counter) that I guess I need to sell to fund the L92. Since it's all stock or stock replacement parts, there's nothing really to test IMHO.

The C6-Z06 T56 is the strongest donor, but for those more readily available std. C5 T56 MM6 units, I added part numbers to the write-up to allow you to add the 1pc MM6 countershaft to any C5 MM6 donor to make it equivilent to the C6-Z06 T56.. (This also allows use of the stock SSR tailhousing, needing only milling on the shifter pad, not boring of the bushing)

BlazinT/A

iTrader: (10)

ok cool im starting my twin turbo project the 1st of november so will be building a new trans this winter. thanks for the great info

Mike454SS

iTrader: (4)

85MikeTPI, have you ever face plated a T56? I'm considering upgrading to the SSR main, and face plating the gears in the trans as I want the strength, and I also want to be able to shift as fast as a face plated trans can allow.

I'd prefer to use the MM6 ratios, and 1 piece counter shaft, it's going into my Caprice, which will is a heavy car, and with the power I hope the new engine makes, I need a strong transmission.

I'm also considering a TR6060 or "T56 Magnum"...but I already have an F-Body T56 in perfect condition to use...having trouble deciding which route to go.

85MikeTPI

iTrader: (9)

Personally, No.. Rick (LS123) has had Liberty faceplate C5/C6 T56s before, so the concept should be the same.. I believe you have to use a Fbody input shaft for the face plating, as the double-cone input shafts won't support the welding of the faceplate engagement. There may have also been a requirement to use one of Libertys mainshafts for faceplating, but Rick could probably elaborate better then me trying to remember the conversation.

Personally, I think if the car is street/strip, the extra friction surfaces of the triple/double cone synchros will go along way to supporting the power and higher RPM shifting, over the base Fbody T56. If you definitely want to faceplace, stick with your base Fbody T56 and have an upgraded viper mainshaft added.

Mike454SS

iTrader: (4)

Spent the day at the track today and talked to many people with FAST stick cars...not going to bother with faceplating. Just going to build the strongest T56 I can from the info you've posted.

85MikeTPI

iTrader: (9)

Just wanted to update the thread that I'm continually updating/revising the build write-up and working on several new options for the buildup and tailhousings. (I've got about $3,000 of my own money tied up in T56 parts, so sometimes updates have to wait for the next paycheck.. )

Anyway, I have the P/N's from Rick (LS123) and verified, to allow a std. C5 MM6 to upgrade to the C6-Z06 1pc countershaft for about $500. I'll probably be doing a major re-write on the buildup in the next month or so to make some of these options easier to understand.

mike

LS123

iTrader: (11)

If you have a dedicated track car, there is nothing better than a faceplated T56. If it's street/strip I would stick with built T56.

Mike454SS

iTrader: (4)

I want to drive it to work at least once in a while.

I just wish I could find a donor C5 MM6 trans. I want to order the SSR tail housing and mainshaft from GM probably monday...and I'd like to find a donor trans asap so I can start building.

LS123

iTrader: (11)

Like Mike stated, C6 Z06 is the best starting T56. There is one on Vette forum.

http://forums.corvetteforum.com/c6-p...t-shifter.html

Mike454SS

iTrader: (4)

Wish that trans were closer to home...the guy doesn't seem too willing to ship it.

85MikeTPI

iTrader: (9)

That C6-Z06 trans is right up the road from me.. If you make a deal with him, I could pick it up and ship it to you.

Seems pricey though. As I just mentioned, for $500 you can make any C5 MM5 into a C6-Z06 with the 1pc counter, the splined rev drive gear, and the 5th and 6th thrust washers..



I've also worked out an intermediate option for anyone with an existing Fbody tailhousing. By using a viper modified Fbody tailhousing from D&D, Tick, etc. and machining down the OD of the TH400 slip yoke, you can get 90-95% of the power levels of the TH400 slip-yoke, without the radical tailhousing modifications to support the 1.885" bushing and seal. I'll probably have a batch of slip-yokes machined if anyone is interested, and I'll be updating the write-up with info and pics.

Mike454SS

iTrader: (4)

IF I understand your pdf correctly...if I have an F-Body LS1 T56, and a C6 ZO6 as a donor, I don't need to purchase a whole lot more.

Far as I can tell, I'll need to purchase the SSR mainshaft, tailhousing, seal, 1st gear synchro retainer parts and VSS ring. I could bore the F-Body tailhousing, but milling the shifter pad seems more convenient, less touchy on tolerances, and leaves all the material that was cast into it around the bushing. Then I will just need to machine first gear for the different synchro retaining ring...right? Short of that it sounds like I'd just then need to replace any bearings that aren't in good shape (I bet they're all fine though), same for blocker rings, and buy a slipyoke for my driveshaft.

I feel like if I can get the C6 ZO6 donor trans in good shape for a good price, that this is the route to take...I've rebuilt a few T56's before, so I'm not too worried about the actual assembly...they've just always been to replace broken synchro keys or once for all new bearings when a friend had a leak and ran his trans dry...and it'll be basically the strongest T56 I could buy/build...which should go well in my 4500+ pound twin turbo sedan behind a twin disc clutch...

...am I confused, or am I on the right track?

I forgot to include the bronze fork pads and billet keys...looking at your teardown pictures, it looks like they still used the aluminum 3-4 fork in the C6 stuff...I thought GM went to the steel one at some point, but I guess not. No big deal, thats a relatively inexpensive part.

85MikeTPI

iTrader: (9)

That's pretty much it.. As you remembered below, the aftermarket upgrades are still nice to have (billet keys, bronze pads) if your F-body T56 doesn't have them already to re-use.

Yup.. I built my own unit this way... (The SSR tailhousing includes the bushing and seal BTW) Since I was preparing the PDF write-up, the build pics are heavy, but you can get the idea from my buildup pics:

http://www.eecis.udel.edu/~davis/z28...100201_LS7T56/

Yup.. The MM6 gearset with the SSR mainshaft should work great in that application.

The steel 3-4 fork was made standard by GM around the 2002 timeframe in the Vette. All the GM units since 2003+ should have steel 3-4 forks. All the triple/double cone units should also have solid metal 1-2 synchro keys. You should just need the bronze pad set, and billet keys for 3-4 and 5-6. (I put them on Rev also for my unit... LOL)

I'm currently in the process of building another from a C6-Z06 unit with broken 3rd gear..

http://www.eecis.udel.edu/~davis/z28...01013_SSR_LS7/

Mike454SS

iTrader: (4)

Cool.

I'll try to post any issues I run into along the way, but going on what you've given us here, I don't think there's much I can miss.

...and I'm also considering some type of surface treatment on the gears (polishing of some sort) but I don't know if I'll bother.

Mike454SS

iTrader: (4)

Just ordered my SSR tail housing, 2 half ring synchro retainers as well as the 1 outer ring retainer and an SSR VSS wheel...the engine this is going behind will require LOTS of tuning...so changing the VSS to 40 pulses per revolution in the PCM is no big deal at all, and means less machine work for me. All direct from GM. When I get it, I'll put the tail housing in a mill at work and bring the shifter mounting pad down to F-Body height, and I won't have much machining left to do at all...just the first gear step lip machining...which I'll also do myself.

Putting together the list of parts to buy from Tremec next.

85MikeTPI

iTrader: (9)

Updated write-up

I've been adding points, clarifications, and other things to the write-up continually, but thought the latest update deserved attention.

The write-up is still at the same location:
http://www.eecis.udel.edu/~davis/z28..._Fbody_T56.pdf

New points of interest:
- Part Numbers for GM 1pc MM6 countershaft "kit" to upgrade any C5 MM6 to C6-Z06 T56 specs (Can be used on any F-body MM6 IF(!) the double-cone 5-6 drive gears from a C5 are used)

- Details/availability of caged needle bearing spacers to install 1pc countershaft into F-body tailhousings.

- Details/availability of using "viper-mod" F-body tailhousings with the stronger/better SSR upgrade. (Get your viper-mod tailhousing from D&D, Tick, TDP, etc. and just machine a TH400 yoke)

- Detailed chart/explanation of GM T56 gear teeth and gear ratios (with some comments on strength)

Comments are always welcome.

thanks
mike

Mike454SS

iTrader: (4)

I'd be cautious machining a yoke to a smaller minor diameter. I know it's not a HUGE change...but I've seen yokes crack along the splines (usually at a seam weld on a cheaper yoke)...so it is probably worth advocating a forged yoke, preferably a chromoly one like those offered by Strange if you are planning to turn the major diameter down to fit inside a viper tail housing.

Also important to get a good surface finish on the outside of the yoke (as good as or better than original) so it doesn't wear the bushing and seal out incredibly fast.

85MikeTPI

iTrader: (9)

Yup.. Obviously the 1pc countershaft and SSR tailhousing are the optimal combo, but for some, the cost and convenience of alternatives outweigh the slight loss of strength.

thanks...