I'm the original owner of a 85 2M6, SE, 4-speed. when I test drove the car many years ago, I remember having trouble finding reverse and subsequently found out that it was a common issue and once you got used to it kind of solved itself. Fast forward to now. I've done all of the maintenance on the car and in actuality it has had virtually nothing break that I couldn't fix. Getting into reverse is still a bit of a challenge but instead of being just hard, I tend to get some grinding unless the shift is done real fast and with a lot of force. I don't think it's an air in the line issue because all the other shift are fine including into 1st from a dead stop.
There are two linkage cables into the trans and only one can be adjusted at that point. I have not removed the plate that covers the shifter end. Would the adjustment for the shift into reverse be at the transmission end or are there also adjustments at the shifter.?
I have not removed the plate that covers the shifter end. Would the adjustment for the shift into reverse be at the transmission end or are there also adjustments at the shifter?
Wear of shifter components could compromise shift-ability, but all cable adjustment is done at the transmission end (although the "plate" over the shifter needs to be removed during adjustment in order to properly line the levers up).
If you can shift easily enough into reverse with the engine not running, perhaps double-check that the clutch is indeed disengaging completely.
[This message has been edited by Patrick (edited 11-09-2021).]
Engine off shifts are fine so that would likely point to the disengagement issue you pointed out. Time to purge the old fluid, replace and bleed. I don't have any leakage so I don't want to mess with replacing any of the cylinders unless absolutely necessary.
If you haven't had the shifter surround off, then the cables can't be adjusted properly. Pins are inserted in the shifter to hold it in a specified position so that the cable adjustment can be done properly. Also, Reverse doesn't have a synchronizer. Other conditions mentioned may also be a factor.
The original single seal slaves were/are notorious for allowing air to be sucked in, even if fluid wasn't leaking out. This is the reason why Rodney had double seal slaves made in the first place... and is why I suggest that replacement slave cylinders only be bought from him.
Brings back memories. Cables and connectors start to wear out and have slack.
There is a procedure to adjust the cables by using pins at the shifter. But I found that it does not fix the issue 100% and I had to move it around a little bit and just test it.
But it does sound like you have air in your system. I have replaced a couple slave cylinders in the parking lot where I used to work. not something you want to get good at. I used a power bleeder but there are several ways to bleed the system. Its probably over due for a flush anyway.
The shift inTo 2nd then to reverse is interesting because that was also suggested to me for my 63 VETTE many years ago. I did try that but no difference. I didn’t realize know that the original recommended lube was regular engine oil of the correct viscosity, and also that the oil change frequency was different than a regular manual trans or differential. I will be changing the oil and using GM synchromesh, swapping out the slave cylinder with the double seal version and purging the fluid.
I am in the process of selling the car and the clunk into reverse is a deal breaker especially when you get someone who has no mechanical background. I had one potential buyer go back and tell his “mechanic” about the noise and he was told the trans would have to be rebuilt! Don’t know how any mechanic could reach that conclusion without a first hand examination of the car not to mention eliminating all of the other possibilities mentIoned on this site.
All of this feedback has been very helpful and is greatly appreciated.
I’ll report back my results.
[This message has been edited by TOM SUTCLIFFE (edited 11-17-2021).]
Potentially dumb question. The slave I purchased from Rodney came with the shaft. The shaft has a protective boot as you expect, but is not physically attach to the end of the slave piston. What prevents that rod from going off axis after it is installed? The clutch fork arm has a dimple on the lever to keep it centered, but I can’t see if the piston end also has the same profile for the other end to sit in.
[This message has been edited by TOM SUTCLIFFE (edited 11-17-2021).]
One more thing. The clutch pedal might be slightly bent. This reduces the effectiveness of an already marginal clutch system. I posted a DIY fix years ago, but I'm pretty sure dickman sells an adjustable pushrod.
A lot of people are suggesting that the system needs to be bled. It could be the master is not being used to is full potential to supply the slave the required amount of fluid.
Sorry this didn't dawn on me sooner. I've been out of the loop for a while.
[This message has been edited by buddycraigg (edited 11-18-2021).]
I don't know why so many need an adjustable master cylinder pushrod. I have installed 2 of Rodney's master cylinders and slave cylinders on my cars and used the standard push rods. They work just fine. If something needs adjusted, then something isn't right.
My 85 had a problem getting into reverse. I took the center console out when I was doing the interior and drove it, it shifted fine. Turned out it was the shift boot retainer that fits under the console. It's plastic so it will give a bit and make it hard to get into reverse. I purchased Rodneys metal one and notched it out with a Dremel on the left, driver side between reverse and 2nd. Problem solved!
My 85 GT had the aluminum clutch pedal assy, it did bend and caused this exact problem before the warrantee expired. Dealer replaced the clutch under warrantee...all along it was the clutch pedal assy bending.
not something you want to get good at.
