Another T56 Magnum XL Blues Story

Posting this in hopes that it helps someone out. Story about how going to the wrong shop for my t56 swap cost me alot of money 500 miles later.

When doing the swap in an '11 or '12 coyote, you NEED the shim for your slave cylinder that is inside of your old transmission. The shop that installed my t56 didn't know this/didn't care to find out, so they didn't. This caused a semi strange clutch feel and some slight issues with gear engagement buthe I didn't read too much into it initially because 1) it was a totally different driveline setup, and 2) I hadn't driven my car in 7 months (deployment) so I didn't have an exact comparison metric.

Anyways, without this shim installed between your slave cylinder and trans, you'll basically immediately rupture your seals in the slave cylinder, and at that point it becomes anyone's guess as to when it fully fails. Mine took about 500 miles.

The 2nd shop I went to to get the issue fixed, Virginia Speed in Virginia Beach, went way above and beyond to get me fixed up. For guys who are admittedly not proficient with the coyote platform, they put in the effort and research. After phone calls to both American Muscle and JPC Racing, and a couple days of putting in and removing the transmission to get measurements, they finally got to the bottom of the shim issue. It's necessary in '11 and some '12 models made before a certain date.

Turns out my original shop no longer had my old transmission to get the shim, and became EXTREMELY unpleasant once they learned i had gone to another shop to get their mistake fixed. They then literally created this shim from scratch using one of their in house engineers and a CNC machine.

All in all this ordeal left me without my car for about 5 days and a good bit of cash spent. But I did learn a good bit and at the end of the day my car now shifts WAY better than it did after driving it home initially after getting the swap done.

Hope anyone considering a t56 swap reads this and can inform their shop to hopefully prevent them from having to go through this. Don't let this shy you away from the t56, it's phenomenal now that it's up to 100%

Thanks for sharing.
I too did this swap on a '14 GT500 and I'm crossing my fingers no issues like this, glad it's fixed for you.
-J

Do you know for sure or not if the shim is required for a 2014 5.0? I just finished my T-56 Magnum XL install last week and have 8 miles on the setup total. 4th gear feels weird.

I'm not 100% sure. I contacted JPC racing last week and asked them just for my own peace of mind, and they said they've done installs with and without. They suggested doing what my shop did, which is taking measurements with the transmission back up in the car to check clearances and make sure you're not going to overextend the slave.
so I'd contact your shop and see if they did in fact take those measurements, and if they did not, ask them to do those so that you don't have to see them again in 500 miles.

things I've noticed: I've got about 800 miles on it since I wrote this post, and it feels fine, but in neutral, sometimes, when its warmed up, it sounds like a "box of rocks rolling around" and the sound goes away when you press the clutch.
I've done some research on this, stemming into other platform forums, and the conclusion that *I* have reached is that this is normal. a lot of other users have noted this same noise and say its just a characteristic of some of the T56.

One other thing I've noticed is that while my 4th doesn't feel "weird" it does sound like theres a slight hollow rumbling sound under light load in 4th gear. gets drowned out by exhaust/road noise when more throttle is applied. this noise seems less common, but many users have also noted that this still falls within the realm of "common"

all in all I'm not too worried. if something goes, it goes. and if it does, i'll contact tremec and see what I can do to get the thing fixed. all in all I love the T56 and hope it stays with me for years to come.

Mine has been installed on my 2011 for around 15,000 miles and it has performed better over time. Initially it was very notchy and down shifting into second took some effort. Also, there was a clunk sound during the 1-2 shift when driving slowly, but i don't hear or feel it as often.