Hello everyone,

I am new to the corvette forum. Recently purchased a torch red 2003 Z06 with 39,500 miles on it. I live in East Texas, about an hour and 45min from Dallas.

It came with an MGW short throw shifter. Put about 300 miles on it and its been shifting seemingly fine, just hard to move shifter which I attributed to it being a short throw. Last week I unscrewed the ball so it would sit higher and it felt better to me going through the gears, parked in the garage. When I did this it would not go into reverse (still parked in the garage). I thought maybe two teeth are resting on each other and once I get it out of the garage it would be fine. Later that day I took it out for a drive and all gears seemed to shift fine including reverse, went on a country road by my house. Did a third gear pull up to 5000 RPM and quickly shifted into 4th. No audible concerning sound that I could hear but went for 5th and it would not go in. Parked the car and tried going through the gears but will not go into anything other than 4th or neutral.

Had it towed to the local Chevy dealer and just got the bad news. They are telling me the trans and all its parts are discontinued from GM. There are shift forks etc available but it would be O.E. not OEM. They are saying my best option is to put a used trans from a 25,000 mile Z06 and it would cost $5,400 out the door.

Obviously I am somewhat livid since I never take any cars I have owned to redline and have driven many manual cars in the past. Has this happened to someone else? What are my potential options? Did lengthening the ball mess up the travel of the throw and cause damage? Sounds like the dealer doesn't want to open up the trans and just replace the whole thing. Also attached picture of the car.

Any help would be greatly appreciated!

Thank you

 

STOP!!!!!!!!!!!!

Walk away,,, NO,,,NO,,,, RUN from that STEALERSHIP!






There are SOOOO many simple things that can contribute to the issues that you are having that you MUST check before you resort to tearing out the transmission!

1. Take off the console plastic and examine the shifter, the lower box, the connection between the shifter shaft and the shift rod. Look for loose bolts lost motion etc..

2. What Master cylinder do you have and is the master cylinder FULL of clean fresh fluid??

3. Can you shift into ALL gears with the engine OFF. What does the shifter feel like with the engine OFF??


4. Put the car on a flat level smooth road or parking lot lot.
If you fully Depress the clutch, shift to 1st and rev the engine, DOES the car try to drift forward?????

5. Is the shifter properly neutral aligned?

6. Try and lubricate the lower shift rod bushings and see if the shifter feels better.

If you need to call me!! PM SENT.. PLEASE do NOT let that Stealership rip you off and replace a possibly perfectly good trans.

That's probably how they got the one that they are trying to get you to purchase.





Bill C

 

Your second post, welcome aboard!
I will only add one thing to Bill Curlee's post above; listen to Bill Curlee! He knows his stuff.
Report back with your findings, we like to see results.

 

Thank you! I will contact him.

 

Bill is 500% correct they are ripping you off. You can get your trans rebuilt for $1200 or so. R&R probably $1200 too. It may just be adjustment of the shifter.

these guys are in your area:
https://texasdrivetrainperformance.com/

A phone call is free. They have rebuilt a couple trans for me and they are very good at what they do. If you don't have a shop to do the remove and reinstall nearby, they may be able to recommend one.

Be sure to install a REMOTE CLUTCH BLEEDER if you do a search on this site, you will find out what this is. (homework assignment)

 

Bill,

This information is incredible. Thank you for answering my post quickly and with excellent info. The car is at the stealership now for the column lock recall. I will have the car towed back to my house so I can take a look at it, equipped with your advice.

To answer some of your questions:
- When I purchased the car I read on the forum that it is vital to have clean clutch fluid as it takes the most abuse. So one of the first things I did was buy some fluid and used the "ranger" technique (which is with the automotive syringe). After 150 pumps of the pedal while cycling in new fluid 3 times it is clean in the reservoir. Attached is picture of old fluid and what it looks like now.

- Engine off or on doesn't make a difference. The shifter will only go into Neutral or 4th

- Im not sure if the shifter is Neutral aligned. How can I check for that?

- What lubricant would you recommend for the lower shift rod bushing?

Thank you for your assistance

 

See if this file helps. Aftermarket shifters may not have the neutral lock pin as shown, but I think you can use a correct size allen wrench.

 

Well,, You have to start at the shifter.. Remove the console and the plastic around the radio & HVAC modules.

Once you do that, find a drill bit that will fit SNUG in the little hole on the front of the shifter lower box snout.





GM supplies this little L shapped pin that probably will not be there any more. Just use a drill bit and go to N on the shifter. Move the shifter until the pin will insert into the hole. Once the shifter is LOCKED by the pin, shake the shifter handle and see if there is ANY LOST MOTION. There should NOT be any. Get that far and post results.

If you find lost motion, and I think you will, address that and see where you are. Most find the four bolts that secure the shifter to the bottom housing are loose or the coupling that connect the rod to the box is loose.

BC

 

Bill,

I got to the shifter assembly and put a small allen key inside the hole to lock it up. Trying to move shifter and doesnt budge. It is firmly locked up. What is the next step?

Thank you

 

So,, The lower box is solid and does not have any lost motion at the Torque Tube mount?

The coupler doesnt have any lost motion?

When the shifter is locked up with the pin, is the handle 90 degrees vertical in the center N gate?

The shifter to lower box is bolted solid?

OPEN up the shifter/lower box and inspect the plastic bushing ball and make sure that the shaft is lubed inside the lower box.

Bill

 

Loosened the two bolts holding the lower box and one securing the collar for the shaft. Went through the steps to neutral align. Turns out it was all aligned and didn't need adjustment. Greased the shaft bushings and re-greased the plastic bushing ball. 4 bolts holding the MGW shifter assembly to the lower box were solid and lower box assembly is solid on the torque tube mount as well.

- When shifter is locked up with the pin, the handle is 90 degrees vertical in the correct position

Put all back together and tried to row through gears, same result I can only go into Neutral or 4th. I can now move the shifter left and right a 1/4 inch but I believe that is from the shaft being greased and able to twist slightly.

When I start the engine there is nothing audible to me coming from the clutch area, which I know is not always a clear indicator just thought I should make a note of it.

Jamie

 

I referenced this PDF several times on my phone while checking on the lower box and shifter assembly. Thanks a bunch for sending it my way!

 

I went back and read your original post. How you drove the car should not have busted the trans, unless something was ready to go. Lots of people shift hard and push the car. My 2000 FRC has seen hard track duty for many years and I have never had any trouble with the trans.

There are a few things that come to mind:

1. With the car in neutral, engine running, clutch in, does the car want to move when you put it in 4th. this might indicate clutch problems of some sort.
2. Can you drive the car in 4th (as a test only to eliminate clutch issues)
3. The shifter forks have a wear point where they sit in the slider gear groove, wear there will jam stuff up. If you google Tremec T56, you can find the repair manual that will be close to yours, You have slightly different gear ratios in the M12.
4. Of course there's the famous paper shims Tremec uses. All the rebuilders put brass back in ( I think that's what they use)
5. I'm not a big fan of short throw shifters, but that is personal taste. That being said, maybe there is something like a worn trans and the short throw. There are lots of folks with short throws that like them and have no problem AND pound the crap out of their car with no problem
6. Have you changed the trans fluid? That would be one thing to try. Use Dexron III. DO NOT USE GEAR OIL!!!!!. drain into something so you can see if there are any particles. I have a pumper I bought on Amazon that looks like the liquid hand soap pumpers, but sized for 1qt plastic oil containers. You will need something like this as the fill plug is on the side.
7. I think there are neutral detent *****, and I recall several years back that folks were messing with the detent springs to smooth up shifting. Just a memory of reading about them here. I have no direct experience on this.

 

Also, if it has not been stated before double check that the screw/bolt that connects the shifter to rod linkage that goes back to the trans is not loose.

Bought my car in June, didn't even start modding, and two weeks after I got the car, the shifter started acting up. Difficult to go into gear and sometimes wouldn't.

I thought my trans was going out. I decided to check the shifter and that linkage bolt had come loose. Tightened it to proper spec (22 lb-ft) and put some blue Locktite on it and it was perfect afterwards.

 

if you do end up needing a trans rebuild I also recommend Jason at TDP, he is a good guy and won't do you wrong

 

If you still are able to remove the shifter from the box, see if you can insert a rod or dowl into the shift box yoke and manually rotate it left and righ and forward and aft just like the shifter would.

Could be something wrong with the actual shifter.

Can you solidly mount the shifter in a vise or clamp it to something solid and move the handle thru all its range of motion??

I still find it difficult to believe that its a trans issue.

Bill

 

yeah I agree, it's hard to believe the trans could all of a sudden take a crap and only at a 5k rpm shift... have you bothered to check the trans fluid level?

 

I did try that as well with the shifter out and a small piece of wood. With it out, I am able to easily move shifter through its full range of motion.

 

After exhausting all the external causes of your issue, it looks like there could be an internal problem causing your shifting problems.

Here is the plate that actually controls the shift gates that you feel.



The SPRING at the bottom of this plate controls the STICK CENTERING that you feel on the OEM Stick. If you have a shifter with centering springs, that shifter complements the internal trans spring.

Here is a post that details all the parts that are inside your transmission. It was posted by RICK KIM. He now owns and operates RKT56 Performance.

- C5 ragtopws6, T-56 Build (whats in my tranny?) : http://forums.corvetteforum.com/nort...-smoother.html


Call and speak with Rick and see if he can shed any light on what the issue could be.

Are you able to remove that housing on top of the transmission to see if the issue that is causing shift issues is being caused by the ball detent and shift gate follower??

- C5 ragtopws6, T-56 Build (whats in my tranny?) : http://forums.corvetteforum.com/nort...-smoother.html

There are several thing that can cause shift related problems inside the T-56. One is the small guide keys on the ends of the shift fork. The other is the small dog keys in each gear slider. I can not see how all of those would fail at one time.


Are you able to remove your own trans/differential if the trans has non repairable issues??????

Bill

 

Picture of that housing on top of the T-56: