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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
After removing the dynamat or what ever it is pretty messy. I was trying to remove the shifter but could not get it to come out of the clamp where the shifter rod goes into the tube to trans. After getting angry I went inside and saw that the oem shifter has the metal mounting bracket on opposite side. So I was never going to get it in. So I cut my loss and put it back together and went for test drive. Could not get into 1st or 2nd. So opened it up again small adjustment and made sure to do up the bolts tight. Went out for drive and all gears working. After more tests I have concluded that the 3rd gear grinding is only happening when going down a gear 99% of the time. So ifI am cruising at 50mph in 4th and down shift into 3rd it will grind.
i did about 10 shifts from 2nd to 3rd at 75 % throttle and not even once did it grind. So WOT from 2nd to 3rd is okay with no grinding.
Does this still smell of a synchro issue or possibly a trans fluid pressure issue? Maybe low on fluid?
So for now I have left the console trim off until I know what is going to happen next.
I will try bliping the throttle when down shifting tomorrow to see if that makes any difference. I see they some has the auto blip for sale on this site, interesting!
This is what it looks like under the black stuff after I removed the rubber cover.
oh wow.... so when he did sound deadening he covered the entire opening and it prob melted down into the shifter. wonder if the melted goo is keeping if from going all the way into position
So I was having a similar 3rd gear issue with my t56 in my MY2007 Z06. It turned out to be a couple of problems: First, the lower box bushings were trashed. It was metal to metal and the shift box literally had metal shavings in it from the box. I changed it out when I purchased a MGW shifter. That helped, but shifting was still notchy. So, I started messing with different fluids. No difference with Mobil One. Long story short, Royal Purple synchromesh fixed it! Transmission is so much quieter and shifts like butter.
So I was having a similar 3rd gear issue with my t56 in my MY2007 Z06. It turned out to be a couple of problems: First, the lower box bushings were trashed. It was metal to metal and the shift box literally had metal shavings in it from the box. I changed it out when I purchased a MGW shifter. That helped, but shifting was still notchy. So, I started messing with different fluids. No difference with Mobil One. Long story short, Royal Purple synchromesh fixed it! Transmission is so much quieter and shifts like butter.
Well just to update. After looking at video clip it would seem like my short throw also has worn bushings. There is way to much lateral movement in it when I wiggle the shifter you can see it move around. So first is to get that sorted. I have decided to rip out the short throw and install the OEM shifter. However I can't just bolt it up I need to flip it over because of the conversion. So it needs to be modded rod pulled out, that end cap has to be cut as this is where it will link to the transmission. I am hoping this will solve the issue.
Speaking with the transmission guy today. He said he sees it all the time boxes needing rebuilds because people put short throws on boxes with synchros. He said if you like rebuilding boxes use a short throw if not, use the stock shifter. Synchro boxes are not made to be quick shifted. So hearing that back to stock and hope it cures the problem.
Well just to update. After looking at video clip it would seem like my short throw also has worn bushings. There is way to much lateral movement in it when I wiggle the shifter you can see it move around. So first is to get that sorted. I have decided to rip out the short throw and install the OEM shifter. However I can't just bolt it up I need to flip it over because of the conversion. So it needs to be modded rod pulled out, that end cap has to be cut as this is where it will link to the transmission. I am hoping this will solve the issue.
Speaking with the transmission guy today. He said he sees it all the time boxes needing rebuilds because people put short throws on boxes with synchros. He said if you like rebuilding boxes use a short throw if not, use the stock shifter. Synchro boxes are not made to be quick shifted. So hearing that back to stock and hope it cures the problem.
It's not uncommon to see shrapnel from the shaft bushings inside the box. They are bronzs on plastic in the cap too, along with the rubber Torque Tube Bushings it's just not a great setup. Here's a couple pics of my lower box, it addresses all of these issues. Bushing on the cap (front) end is reolaced with a new seal and bearing. Plastic cap is replaced with a billet aluminum cap. Factory bushing (rear) the one that failed in above video, is machuned out, new seat is milled for new bearing, seal. Your choice of Delrin or Poly Torque Tube Bushings .
Does anyone think with bushings gone like the video below and the slack in the linkage could cause grinding issues when changing gears?
Guessing it's possible,
First is getting bushings etc straightened out, then see.
Hate throwing parts at anything, but some things have to be made right first before getting to an issue deeper inside.
Guessing it's possible,
First is getting bushings etc straightened out, then see.
Hate throwing parts at anything, but some things have to be made right first before getting to an issue deeper inside.
Exactly...I’m always going to eliminate the easy and obvious before I tear into a transmission. Linkage properly aligned, healthy hydraulics, high end fluids.
Exactly...I’m always going to eliminate the easy and obvious before I tear into a transmission. Linkage properly aligned, healthy hydraulics, high end fluids.
Went back, re-examined photos.
Good grief.
FIRST clean out 'sound proofing' from tunnel area. Then one can see. Always a great start.
If me box comes out too for a thorough inspection of grommets, whole 9 yards & by someone who knows WTH they're looking at.
Repair/replace PRN, reassemble, readjust linkage & test. End of Line.
And y'know M, when all's said & done?
Occam's Razor's points to a failing/ed synch.
Here is an update on my situation. I managed to remove the lower shift box. The fin on the lower box is ground off here and the lower box has a layer or silicone in between it and the torque tube. One of the reasons why I could not slide it out.
I replaced the lower box with the OEM one left the fin in place as it bolted up fine and not interferring with anything as the mounting holes lined up. I exchanged over the rod from the short throw as it had a notch ground out too for use in a converted car foe RHD.
I mounted it all back up and went for drive. Immediately I loved the OEM shifter more just more smooth. It also sits a lot lower so much more comfortable.
Unfortunately the grinding is still present but it is a bit better. Mostly grinding happens from 4th to 3rd. Did not really have an issue on harder acceleration from 2nd to 3rd.
It would seem like it is the synchro then. Damn..
I did notice the linkage system on a converted car is different to original LHD cars. On LHD cars the linkage is in place and you can't move it. On RHD the linkage just falls down once lower shifter box removed. You can wiggle the linkage around as nothing is holding it in place. Not sure if that is an issue or can be done like that for converted cars.
Also under slight acceleration I notice the shifter assembly and torque tube do move a lot when you give it gas. It kinda looks like the torque tube jumps around once power goes through it and rattling noises coming from where there. I can see this as I have the center console panel off.
TMOD those look like great units awesome job there!
I think the linkage looks the same as on LHD cars as they look like they will also drop off once the bolt comes out.
Also looking at the OEM shifter once install the bolts that hold it to the torque tube are aligned differently than the short throw mounting location. I find this odd as it should be the same???
Well I ended up adjusting the shifter so it sits like it did previously pushed it more back into the linkage.
The grinding still there on the 4 to 3 shift not that I drive like that, I just so happened to do it once and found this problem. Now it has been doing my head in ever since. Today took it for a long drive no issues on 2 to 3 shift. The OEM shifter feels so much better.
Other than a fluid swap it looks like transmission will need to come out.
I have read to go with the updated 2011 parts as they are better designed.
To go with carbon blocker rings on 1-4. Billet keys on 3-4 synchro assembly, replace plastic shift fork pads with steel ones, and swap alloy shift fork 3-4 to a steel one.
03-12-2018, 02:24 AM
