Brand New T56 Magnum XL rear seal pop out

[dazwelding]

**I have the T56 Magnum, not the XL**

I installed a new T56 Magnum in my 03 Cobra, and had issues with the bellhousing (see my other thread on that if you are interested). I took it to Pro-Dyno for them to figure out the issue in the bellhousing and to get the Cobra driving. They finished it up, and I picked it up on Saturday. I got about a little over 1 mile away and saw smoke coming out from under the car. I took it back to Pro-Dyno. They found the rear seal popped out of the trans. They put it back, and I picked it up Wednesday after work. My coworker followed me for a couple of miles and we did not see smoke so I kept going home. I made it close to 60 miles on back roads (almost home by the way) and the trans got stuck in gear, but the shifter is not stuck. I hear some sound, I pulled over, put the shifter in neutral, let the clutch out and the car stalled. I looked under the car and the rear seal popped out again. There is fluid all under the car. I had to get the car towed the rest of the way home.

Anyone else have issues with a brand new T56 Magnum? How about having a rear seal pop out of any T56?

 

[olympic]

Sounds like it's building pressure inside the trans, likely because the vent is not working. Unfortunately the trans has to be dropped

to look at it.

 

[dazwelding]

We got the Cobra back up on jack stands, pressed the seal back in, and filled the trans back up. We ran it on the jack stands and rowed through the gears and the seal popped back out again within a few minutes. We did this over and over again, once with the vent tube removed, once with some gasket maker around the seal, and same results each time. We tried to get a new seal, but the one we got was not the right size.

We will see what Tremec says this week, but so far I have found that there have been others with this same issue. Sounds like there are two potential fixes, replace the seal with a different style seal or replace the tail housing. This is so frustrating. We should be driving around in the car now, not working on it again. Not the result I was going for when we purchased all new driveline components.

 

[Mojo88]

I feel your pain. Same type of shit has happened to me LOTS OF TIMES when doing assorted mods on various cars.

I have T56 in my car. It works perfectly. I agree with olympic, there most likely is some pressure building up somehow. Even if the seal was a tad small outer diameter and in there lightly, there is nothing forcing it out (normally).

Is there some way you could fabricate a fitting to go into the fill hole so you could add air into the tranny? Then listen (or feel) if it's escaping out the vent.

Best of luck with the fix. Please post up the results.

 

[MG0h3]

Geez. My biggest concern would be damage to the trans from lack of oil.

I’d try and warranty the whole unit back personally.


Sent from my iPhone using svtperformance.com

 

[CobraBob]

Sorry to hear about your trans failures. Stuff like this is so frustrating. I hope Tremec takes care of you. It's obviously a failed unit. I tend to agree with @MG0h3 about sending the transmission back (for refund or replacement with a new unit).

 

[hotcobra03]

what size is the output shaft on this

 

[Mojo88]

Geez. My biggest concern would be damage to the trans from lack of oil.

I’d try and warranty the whole unit back personally. ......

Yeah, I gotta admit, this would be my preferred approach too. Could be damage from lack of oil. Warranty it back for a new one........ unless they have easy fix AND give you extended warranty on the one you currently have.

Interestingly, I have same tranny (T56 Magnum XL) and I am rebuilding the diff, so I took out the driveshaft, with my drain pan underneath, but no oil came out at all, not one drop..... and it's full.

 

[03' White Snake]

I need to attend to a leaking magnum this winter myself. Mine is leaking from the shifter base. From what I read Tremec tears the seals while installing the shifters and this causes them to leak. They know it's an issue with no real correct fix.

My buddies tail shaft seal popped out on his magnum. My other friend gave him a Viper t56 seal that has a spring on it to help hold it in. If or when my seal finally poppes out I will be installing the same seal. It fixed his seal issue.

 

[dazwelding]

I installed a seal from D&D Performance last weekend and it stayed in and did not leak. Only drove it once for maybe 15-20 miles, but the old seal would have popped out before I even got down my street. If you need a seal that doesn’t leak or pop out call D&D and they will ask for you trans tag numbers to get you the right seal.
Tremec is warranting the trans, and I will be sending it back.

Extremely happy with Tremec customer service so far.

I did start to hear a clunk sound when I let the clutch out on the last few miles of my trip, so now I have to find that before I remove the trans. If it is in the trans good, Tremec will fix it, but if it’s not I will need to be able to drive it around to help diagnose the issue. We will see what that is this weekend.

I also got a new 2020 PP2 GT last weekend, I will have to post some pictures in the S550 section this weekend. It is awesome. Got to drive the Cobra and got to drive the new GT all in one weekend!

 

[dazwelding]

I sent the trans back, Tremec decided it was not worth rebuilding so they sent me a replacement. I cannot stress how happy I am with Tremec. If anyone is considering a change in their manual trans, I would recommend Tremec. I got the replacement trans in last weekend over Memorial Day, and got to start driving it on Monday evening. It is wonderful! Shifts smoother than my 2020!

 

[Lambeau]

Great to hear!

 

[CobraBob]

Now that is some great news. A really happy ending to a sad story. It's great that Tremec has provided you with exceptional customer support/service. Continue to enjoy your new Magnum T-56.

 

[Mojo88]

Wow, nice to hear something good about customer service, from ANYONE. It seems like customer service has given up the ghost with many companies.

 

[IllCobra]

I sent the trans back, Tremec decided it was not worth rebuilding so they sent me a replacement. I cannot stress how happy I am with Tremec. If anyone is considering a change in their manual trans, I would recommend Tremec. I got the replacement trans in last weekend over Memorial Day, and got to start driving it on Monday evening. It is wonderful! Shifts smoother than my 2020!

Where did you buy the trans from?

 

[dazwelding]

Where did you buy the trans from?

Lethal

 

[dazwelding]

Wow, nice to hear something good about customer service, from ANYONE. It seems like customer service has given up the ghost with many companies.

Yes! We have had a few other issues with our build and in our experience it is unfortunately rare that a company stands behind their products these days.

 

[IllCobra]

Lethal

Thanks. Curious, why did you pick the XL or the normal magnum. The only difference between the two is just where the shifter is located, right?

 

[dazwelding]

Thanks. Curious, why did you pick the XL or the normal magnum. The only difference between the two is just where the shifter is located, right?

Well that is interesting, I have the Magnum, NOT the Magnum XL. It looks like the XL has an entirely different tail shaft than the Magnum. As for why, I could be wrong, but my research showed the XL was for 05 and later, the non XL was for the 04 and earlier. I definitely could be wrong about that- obviously I posted I have the XL and I actually have the non XL…..

 

[IllCobra]

Well that is interesting, I have the Magnum, NOT the Magnum XL. It looks like the XL has an entirely different tail shaft than the Magnum. As for why, I could be wrong, but my research showed the XL was for 05 and later, the non XL was for the 04 and earlier. I definitely could be wrong about that- obviously I posted I have the XL and I actually have the non XL…..

I see. I'm doing some research to the magnums too. I would like that to be my next mod but time will tell. Nothing wrong with my T56, I just like all the reviews I've been reading on them and how smooth the shifts are compared to the stock trans.