Rebuild T56 or Replace with Magnum?

[Corbic]

Well my T56 took a shit on me 2 months into owning the car.

Car has 36k miles, 2.2KB and the T56 has a 5.0 Shifter and 26-spline input.

[video]https://youtu.be/nIeWF8-ia5g[/video]

The car pretty much over night started whining like that. I've parked it and have been working on other things since then.

I talked with Jason at Dallas Drivetrain Performance http://texasdrivetrainperformance.com/

Great guy, based on the video, mileage and car, he surmises the 26-spline was not installed correctly and one of the bearings had shifted. Input Shaft and 4th Gear are most likely toast.

So...

Stage II rebuild - $1,080

Carbon Kevlar Synchro Rings
Keys and Springs
Fork Pad Kit
Front and Rear Seals
Billet 1-2 Keys
Billet 3-4 Keys
Bronze, 1,2,3,4,5,6 & Rev, Shift Fork Pads
Bronze Shift Bushings
Steal 3-4 shift fork
Labor


Estimating also
26-spline input - $325
Billet TOB Sleve - $100
Any damaged Gears - $160-230 each

Shipping - there and back - $200


His estimate was $1,500 to $2,000

A Magnum is $3,000 new and most sellers have some sort of discount and free shipping. I should be able to get one for $2,800 delivered. I could also sell my damaged T-56 for a few hundred dollars. It's certainly still worth something even as a core.

Would the above rebuild be stronger then a Magnum? Advertisements list the Magnum at 700 ft/tq, I am currently at 605/544 and I don't see my self moving off that in the next 5 years.

 

[P49Y-CY]

That is sort of a tough call. Keep in mind that the stock unit is very strong esp with upgrades, and that there will be additional modifications necessary with a magnum.

Our cars already have a steel 3/4 fork.

 

[ITSTOCK]

ETA: Your t56 might be a little louder than mine and include some extra noise on top as well. :kaboom:

Does it still shift fine? It appears so in the video. If you do a search here, a lot of people state the same whining sound from their t56 before and after rebuild (most put blame on the input shaft). Mine does it, to be honest, I'm not really concerned.

 

[04cobra88]

I installed a 26 spline on mine it's noisey but mostly a little sloppy I think I messed up the backlash on the input shaft honestly..but yours doesn't sound right I'd I'd spend the extra cash and go magnum , mines coming out this winter for a magnum!

 

[SlowSVT]

If the rebuild bill came to $1500 I would keep the T56 hands down. At $2000 is right at the Magnum tipping point but you still need a $200 yoke, a shorter driveshaft and a speedo sensor. The T56 is a pretty tough gearbox and will have lower parasitic drag then a Magnum with the narrower gear-set and has been known to hold 1000 hp and beyond. Keep in mind the Magnum can use the same upgrades you listed above it comes with the plastic thrust faces, bearings, aluminum 5th and 6th shift forks ect. ect. that stuff adds $600 to the bill and your getting that with your rebuilt T56.

I think I would lean toward rebuilding what you have 60/40

 

[CompO_Eric]

I'd go Magnum. If I could do it again, stick with 2.66 first gear vs 2.97. I'm planning on buying another magnum to fix that mistake


Sent from my iPhone using Tapatalk

 

[Corbic]

I'd go Magnum. If I could do it again, stick with 2.66 first gear vs 2.97. I'm planning on buying another magnum to fix that mistake


Sent from my iPhone using Tapatalk

2.97 has the better overdrive however,

.50 vs .63

 

[CompO_Eric]

2.97 has the better overdrive however,

.50 vs .63

Yeah that's true. But if you drive it on the street the first three gears ****ing suck


Sent from my iPhone using Tapatalk

 

[01yellercobra]

A friend of mine had his T-56 upgraded and went to the .50 6th gear with 3.73's. He told me he wished he had stuck with the stock .62. His cruise rpm is so low it hits boost anytime he tries to accelerate.

 

[99-venom]

Have you checked the fluid level?

My old t5 car would make the same whining noise when it was low on fluid. I'm not sure if the t56 makes the same noise, but transmission fluid is much cheaper than a new transmission. Worth checking.

 

[Corbic]

Saw this on LS1 Tech...

OK, I'll throw in my $0.02 since I have first hand experience of building both T56 and TR6060 transmissions.

If you plan on racing the car, go with the Viper spec T56. I have seen the insides of both transmissions and when you miss a shift on the TR6060, you WILL eat the engagement teeth along with the synchro ring. I had a 2009 C6 Z06 with less than 2,000 miles and the owner was drag racing (there were more tires on the inner wheel wells than on the actual tire) and missed a shift ONCE!!!!! Casual driving, the 2nd gear grinded. Upon disassembly and inspection, the engagement teeth were worn away along with the synchro ring.

I have compared the engagement teeth and synchros on both transmissions. What I found was the T56 has less teeth but they are bigger and more robust compared with TR6060.

I also noticed that the TR6060 gears are wider but the wider gears fit inside the trans case that is same size as T56 case. This is achieved by using a narrower synchro set up and using more engagement teeth to compensate for it.

The reason I would use a Viper spec T56 for racing is that the T56 is more forgiving on a missed shift. Yes the engagement teeth does get rounded off but it's not as bad as the TR6060.

Take a look at the pictures and compare for yourself.

Look how small the engagement teeth are.

Sintered bronze blocking rings. They are not as durable as carbon fiber blockers from T56 IMHO.

The engagement teeth for 1-2 synchro counts are: 46 for T56 and 60 for TR6060.

This is from a 2010 Camaro with 1,200 miles. Guess what happened? :nod:

 

[Corbic]

So I'm still totally at a loss on what to do.

I drained the fluid and replaced it in the car. The fluid was clean ATF, but the car had +5 quarts of fluid.

I took the car around the block, leaving off the body seal boot and shift boot. This aloud for a lot more noise to enter the cabin.

Firstly the car shifted a billion times smother and easier with only 4quarts.

Second, it's the Input shaft.

The whine is 100% throttle based and is consistent across all gears. It will also whine in neutral. The whine gets louder with more throttle input. It only stops when in gear and the clutch is pressed in. In neutral with the clutch pressed in, it whines.

So Rebuild? Sell as a Core and buy a Magnum? Who should rebuild it?

I fear I'll drop $1,500-$2,000 having it rebuilt only to break it and be like "Fawkkk!".

Also, the car has an aluminum drive shaft and DS Hoop. I've heard mention the drive shaft may need shortening with a Magnum?

Also, I still have torque-vectoring, someone mentioned this could be the transmissions fault?!

 

[Fr500handbuilt]

Drain it again and put in gm syncromesh. Then see if it quiets down and shifts smoother.

 

[Corbic]

Drain it again and put in gm syncromesh. Then see if it quiets down and shifts smoother.

What is the goal, check the fluid?

The whine is louder then the engine and exhaust. It's not a faint noise.

 

[Fr500handbuilt]

Well atf is just about the worst thing you can put in a t56.

 

[Corbic]

Well atf is just about the worst thing you can put in a t56.

Except it's exactly what the OEM requires?

 

[Corbic]

So, had the POS rebuilt. It's back to whining and hard shifting. I messed with the clutch adjustment to no avail. Luckily I'm out side the rebuild warranty.

 

[ZR5.0]

Running Chrysler Viper spec fluid in my own with excellent results vs ATF / SYN ATF / Amsoil Syncromesh / GM Syncromesh.

 

[biminiLX]

Running Chrysler Viper spec fluid in my own with excellent results vs ATF / SYN ATF / Amsoil Syncromesh / GM Syncromesh.

Bought from dealer?
Chrysler has to buy it from a common source, like GM synchromesh is made by Pennsoil.
Never heard of Viper spec fluid, maybe try in my Magnum XL.
My magnum and my stock GT500 both have the 2.66/0.50 gear set great for 4.10s
-J