When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I did some digging and Tremec does have documentation on the XL. It's conveniently located in there "pile of literature" on their website - hidden in about 100 PDFs there is a "2016 Performance Aftermarket Product Guide:"
"http://www.tremec.com/anexos/TREMEC-...duct.Guide.pdf
In the snag from that document below, one can see that dimension "A" is input shaft to center of shifter and dim "B" is input shaft. So A-B= dim from trans face plate to center of shifter. 34.9" - 6.52" = 28.38" + 5.5" bell = 33.88. See pics at bottom of this post and you'll see a 5.5" bellhousing and a 30" trans face to center of shifter. 35.5-33 = 1.62" which is easy to make up in a number of ways on its own. So a Magnum XL WILL WORK I think.
George tells me that the Magnum XL leaves a lot to be desired so what I'm going to end up with is the front half just as I have now(basically GM Racing T56) and a tail section from a FR500 unit. I'll use a Terminator Cobra shifter and this is good because I have several around the shop to fit/try and there were plenty of good shifters made for that vehicle.
He says he is going to build this at 36" from the back of the engine to the center of the shifter.
SO a 36" bell to center of shifter transmission should put me perhaps 1/2" farther back with a direct-mount shifter. I think this will work perfectly, actually, as that extra 1/2" will keep me from turning the A/C on at 6500RPM when I grab third with a full fist...shifter is too close to those buttons anyway.
What did George specifically say about the T-56 Magnum XL? I haven't heard a single thing bad about it thus far, and I've been archiving reviews for almost three years.
He said that the outputs are failing in high-stress setups in Mustangs. Now he's dealing with stuff that probably makes more power, turns more tail shaft speed, etc. than I ever likely will so it may be just fine for us mere mortals. I think he is likely thinking I'm doing something like twins and standing mile since I opted for the fluid pump. I figured I am already a bit "out there" budget-wise on this trans so why correct him and not get the best he can put together?
Now the response I got from Tremec on the GM "TBA" part numbers was a but disheartening - "why would we go to all that trouble when our TR6060s are selling so well?" They apparently think they would have to spend unwarranted design/setup money and at the same time cannibalize business that might go to the 6060. But I don't see a bunch of guys swapping in V2 trans so I was scratching my head on that one. Didn't sound like they were planning to fill in a part number there for the GM folks any time soon.
At any rate, not a lot of V1s out there compared to Camaros and such so I'm glad to be even close to something that will fit.
Well, glad to see they're going to take car of the changes! It'll be interesting to see how they get to 36".
I'm interested in seeing that too.
It seems that whatever they'd have to do to extend the tailshaft would leave the T-56 susceptible to the same kind of breakage that the T-56 XL is vulnerable to.
It seems that whatever they'd have to do to extend the tailshaft would leave the T-56 susceptible to the same kind of breakage that the T-56 XL is vulnerable to.
Wonder if this transmission is going to 6060 or t56 internals?
Well, glad to see they're going to take car of the changes! It'll be interesting to see how they get to 36".
What is a GM Racing T-56?
I guess I was wrong to refer to it as an item in itself...not a "shelf" item. I was referring to what RSG builds for GM racing. 2.29 1st real-deal close ratio. Mechanical fluid pump, best of everything I suppose. 6th was going to be something like .7 and I got him to change it to something in the .6 range so I could kinda drop off a RPM cliff and still cruise with tall gears. The actual ratios are on my desk and I'll post them tomorrow.
His exact statement re: The tail was "go look up the Ford 500R" and I need to do some digging and clarifying.
Bottom line he says we'll be pretty darn close with he shifter length if not right on.
If this works, we'll have an option that isn't much more expensive than the typical Magnum-ish build/rebuild that several vendors offer and if you don't opt for the close gears, fluid pump, etc., probably cheaper overall for some projects as you get to keep your own T56 to resell and shifter should be cheaper also. I hope to have a nice and strong Al one-piece driveshaft made with a slip-yoke. No more carrier bearing worries as well.
Again..thought I had the ticket until I measured. This is longer no matter what so confidence is growing. Hopefully I will have it back in a couple of weeks!
So what kind of driveshaft joint have you planned on using? U-joint or CV?
Well I figure I will see how straight I can get things aligned between the tail of the trans and the input of the rear but I figured U-joint. I did a lot of reading about it before I paused the Jeep for this project but have forgotten some of that learned info. Opinions welcome. I assume if the angle difference is low that U-joint is good. :?
Well I figure I will see how straight I can get things aligned between the tail of the trans and the input of the rear but I figured U-joint. I did a lot of reading about it before I paused the Jeep for this project but have forgotten some of that learned info. Opinions welcome. I assume if the angle difference is low that U-joint is good. :?
That's a hard question to answer. Your misalignment angles depend on the height of your motor mounts, trans mount, subframe bushings, and choice of differential. The Getrag, Ford 8.8", and Ford 9" housings place the differential input flange in different places. On the stock driveline with 25,000 miles, sagging support bearing, rubber guibo, and Revshift mounts everywhere else, you'll find:
Transmission Propeller Flange: 2.75 degrees down
OEM Driveshaft, First Section: 3.30 degrees down (Δθ1 = -0.55° @ rubber guibo)
OEM Driveshaft, Second Section: 0.30 degrees down (Δθ2 = +3.00° @ support bearing)
Note that if you put a laser boresight on this setup, the center of the prop flange will nail the center of the differential CV flange. Therefore, it's the center support bearing that's causing the big misalignment angles. (It's also important to note that the driveline gets longer when you spin it, so the loaded CTS-V misalignment angles are less than the static values above.)
I don't see any reason why you shouldn't be able to improve on that and achieve a misalignment angle of 0.25-0.50° degrees on the transmission end (where the U-joint will be) by shimming your custom mount/crossbrace. That should make the angular acceleration of the universal joint almost indistinguishable from a CV joint, even at high speeds. If you're cautious, a dual CV setup will provide the smoothest possible rotation, but you'll pay more and it'll be 5-8 lbs heavier.
Well I figure I will see how straight I can get things aligned between the tail of the trans and the input of the rear but I figured U-joint. I did a lot of reading about it before I paused the Jeep for this project but have forgotten some of that learned info. Opinions welcome. I assume if the angle difference is low that U-joint is good. :?
U-joints are supposed to work at equal angles and the problem with this car is that there isn't enough room to do this. I've been down this road and DSS uses a u-joint/cv combo for a reason. They use a 930 Porsche CV.
It seems that whatever they'd have to do to extend the tailshaft would leave the T-56 susceptible to the same kind of breakage that the T-56 XL is vulnerable to.
I agree; this is a concern but George says he is building something "better." I am shipping the trans back today so should have more conversations next week. He confirmed again 36" engine to center of shifter. I also asked how long overall(engine to output shaft) and he said "add like 2 inches" so this is something a little different from a Magnum XL indeed...as long as those measurements are right. I anxiously await with my tape measure for the return.
Wonder if this transmission is going to 6060 or t56 internals?
Magnum internals. So I suppose the best of the 6060 stuff if there is any difference there. I am confused by the different torque ratings and haven't done the research to figure out what's different. I say this as I've seen a decent amount of evidence that the typical GM 6060 does not carry the same torque rating as the aftermarket Magnums.
08-15-2016, 03:22 PM
