Good Morning!

Thanks to those who responded to my original post. This is a re-post of my tranny/shifter problem in hopes of finding someone who has also had the problem.

INTERMITTENTLY the 4-sp in my 87 Conv.. will not allow shifting into 1st or 2nd...
For example, after backing out of a parking space or when down shifting from 3rd, I can get it to go into reverse or 3 or 4, but not 1st or 2nd. It feels like the shift lever does not engage the 1-2 "channel" and linkage rod.

By moving the shifter back and forth it will finally go into 1st, but when the condition is present, I can pull ahead slowly then push in the clutch, it then feels like something is dragging...like a brake, or perhaps another gear is hung up. I have pulled the driver's seat, console covers, etc, but cannot see anything apparantly wrong with shifter or linkage.

There is one other symptom...on a couple of occassions, when shifting from 1st to 2nd, the shift lever came back farther than is "normal", then as I let the clutch out and applied torque the lever popped forward the half inch, or so to it's "normal" 2nd. gear position. (2nd. gear shift fork? or syncro?)

Since there is no noise in the transmission, grinding into second, popping out of gear, etc. I am convinced that the problem is in the shifter or linkage, but if I can't get some help here, I plan next to remove the side cover from T-10 to check shift lever detents, forks, syncros, etc. (and install short-shift levers while I have it off).

I cannot "make" it fail, it only does it when it wants to. Tranny,O.D. and Diff. were serviced about 2K miles ago...no GM posi-additive was put into tranny...used Valvoline 80w90 gear lube.

Any suggestions gratefully appreciated.

Thanks,
Gary

 

gee... how many miles are on the tranny???

It sounds to me like you might have a bent shift fork... but that would be more consistant.

I am not sure of the lube requirements in the Super T10...

Hopefully, Scorp will chime in, he is the guru of these tranny's.

Just remembered - I read here sometime ago, that if the linkage rods round out, these kinda problems can start.

 

thanks for the input,

I've screwed up and have two threads going now...I posted an update to my original and it didn't show on a refresh, so I posted a new one...Oh well, too much help is better than none at all!!

Lucy has just rolled over 70,000 miles.

I believe it's the guys at GearZone who say to use straight 80w90 gear lube, no synthetics (may cause seal leaks), and the service manual sez to add one bottle of posi-additive.

Are u referring to rounding out at the shifter end or the tranny end?

The 1-2 and 3-4 rods have grommets, spacers and "spring washers" holding them nice and tight at the tranny end, but the reverse rod simply floats in the hole thru the lever on the reverse case end, but no noticible rounding of the hole.

Scorp was on my original post and offered a suggestion or two, which didn't pan out.

Gary

 

UPDATE:

I just received an email from Paul at 5speeds.com, another 4+3 guru.

He suggests the problem is being caused by wear on the reverse lock-out pin allowing me to bias the shifter too far towards reverse, bypassing 1-2. The bias can be adjusted by breaking the weld on the bias bolt, adjusting it to compensate for the worn rod, by moving it in and then tack welding the bolt back into place.

I'll be on it as soon as the markets close today!! and will let you know how went.

Regards,
Gary