Transmission is stuck in gear

[Crimson135]

I've owned my 1998 GTS for about 2 months now. 4th gear grinds no matter what RPM I shift at or how fast or slow I shift it. Double clutching doesn't help either. I knew it would eventually need fixed or rebuilt but it didn't bother me too much.

I washed the car yesterday and went for a drive. I was driving about 45 MPH or so in 3rd gear and everything was fine. It shifted into 3rd without any problems, but while coming to a stop it was stuck in 3rd! I drove the car home and tried to get the shifter to move pretty much the whole way back. No luck, it's stuck for good. Its a stock shifter and has about 300 miles on the dexron fluid. Clutch releases just like it should.

I'm guessing the T56 needs to come out for repair?

[dave6666]

Or all your mounts are worn. I had bad shifting problems till I replaced them. Missed shifts, pop out of gear, etc.

[Crimson135]

Its definately stuck. The engine running or not makes no difference. The trans mount was in great shape when I changed the trans fluid a couple weeks ago. Motor mounts seem fine but I haven't inspected or tested them to see if they're torn.

[Old School]

I’ve been able to finesse a trans stuck to neutral by pulling on the shifter hard at the split second I give a little gas or let off the gas.
Also, 3rd and 4th are on the same slider, so it’s probably not a coincidence.

[dave6666]

Understood on your symptoms. They are similar to what was mine. But visual inspection of mounts is meaningless. Mine looked great but fell apart when removed.

[Crimson135]

Understood on your symptoms. They are similar to what was mine. But visual inspection of mounts is meaningless. Mine looked great but fell apart when removed.

I hear you. I'll check the engine mounts out. The trans mount is solid, no cracks, rips, rubber is still firm, etc.

Does the shifter sit pretty close to the trans tunnel on a viper? I've had bad motor mounts on my old M3 cause mis-shifts and other odd things, but it was fine while not under heavy load.

[98RedGTS]

Agree with dave on the mounts. I replaced mine thinking it was just preventative measures and when they came out both just about fell apart in my hands.

What dextron fluid did you use?

[Crimson135]

I think it was Dex 3. I had initially bought some synchromesh fluid and when I went to replace it, I noticed an orange sticker on the trans saying to use Dex 3. I talked to a couple T56 rebuild shops and they all said to use the dexron over the synchromesh.

[Steve-Indy]

I would suggest Mopar ATF+4 over the Dexron III which is no longer supplied by Mopar.

[pokeyl]

3/4 gears share the same shift dog. Material from you bad 4th gear has locked the dog into 3rd. You need to rebuild/relpace the trans. Even if you get it out of 3rd you could jam in any other gear next time. If you get it unstuck stay out of 3/4 use 1/2 and 5/6 you may be OK to get it to a shop.

https://www.google.com/search?client=safari&channel=mac_bm&biw=1253&bih=745&tbm=isch&sa=1&ei=jh0IXaqSHdyEjLsPy82RmAI&q=t56+transmission+inside&oq=t56+transmission+inside&gs_l=img.3...2620.7545..8937...1.0..0.940.7455.5-3j7......0....1..gws-wiz-img.......0j0i5i30j0i30j0i24.0a42mgfxML4#imgrc=qb8 ZAqfEZwJxeM:

https://bangshift.com/general-news/tech-stories/transmission-tech-we-take-two-junk-t56-transmissions-spare-parts-and-new-pieces-from-american-powertrain-to-make-one/

[Crimson135]

I checked the engine mounts. They aren't torn. I removed the trans crossmember and lowered the trans down some just to make sure it isn't hitting the floor or something goofy. Its still stuck! I agree with pokeyl, unfortunately it seems like my trans needs rebuilt at only 36k miles.

Anyone have experience with Texas Drivetrain Performance? They're about 3 hours away from me. I could easily pull it and drop it off to them. I've got a couple weeks of vacation time I need to use anyways, might take a vacay in South Texas and pick it up on the way back home.

[dave6666]

Have not heard of them but Google says they are 30.2 miles from me.

[Crimson135]

Just an update. I ended up messing around with the shifter and got it unstuck a couple of months ago. I've been driving the car since we've had a mild winter so far here in Oklahoma.

I finally pulled the trans last weekend and took it to Texas Drivetrain Performance this last Monday. They tore the trans apart while I watched and made a list of stuff that needed replaced. There were a couple parts that are useable but not perfect. I had them replace everything that was questionable. They got it done in a couple hours while I shopped at SUMMIT racing. I'm putting it back together tonight with a new clutch, slave cylinder, lightweight flywheel, IPSCO shifter, Gen4 ACR knob, etc. I'm excited to finally get to drive my Viper without it grinding!

[lane_viper]

Just an update. I ended up messing around with the shifter and got it unstuck a couple of months ago. I've been driving the car since we've had a mild winter so far here in Oklahoma.

I finally pulled the trans last weekend and took it to Texas Drivetrain Performance this last Monday. They tore the trans apart while I watched and made a list of stuff that needed replaced. There were a couple parts that are useable but not perfect. I had them replace everything that was questionable. They got it done in a couple hours while I shopped at SUMMIT racing. I'm putting it back together tonight with a new clutch, slave cylinder, lightweight flywheel, IPSCO shifter, Gen4 ACR knob, etc. I'm excited to finally get to drive my Viper without it grinding!

Glad you got it working. I had to rebuild mine when I got it due to it not staying in 5th and 6th. The whole 5th/6th syncro assembly had come apart and ate a thrust washer.
My fluid was metallic when I drained it.

new syncro's, bearings, keys, washer, and a 6th gear, mine was back going again.

I know it's blasphemy, but I use pensoil syncromesh in all 3 of my manuals 2 of them are t56's. Change it out about yearly.