I have an FS5W71B of unknown history that goes into second and third just fine except for a frequent grind.  I understand it’s a fairly common problem and I’m pretty certain it not a clutch release issue because I don’t have a problem getting it into reverse. 
May need new synchros, but I read in a really old post on another forum that putting stronger spread springs behind the shifting inserts helped avoid that problem. The idea was that it pushed the synchros into the cones with more force.  Any experience with that?

Dennis

What gear oil is in it? This is a problem that has been cured in the past with a gear oil change.

I hope that’s it.  I had a fill of GL5 80-90 for about a month and only a few miles, figured out that was a bad thing and drained it out.   I have Redline MT 90 on order and will give it a try soon.  This question was just about getting a step ahead should further action be needed.  

I do like this stuff. Getting pricey and harder to find, at least in my kneck-of-the-woods.

 

I was wondering about the ACDelco solution, but didn’t know if friction modified meant more or less friction. Less didn’t seem like a good idea. Bottom line, if it works, it works.  Maybe I’ll use the fill of Redline to ‘wash away all the remnants of my sin’ of using GL5 and then give ACDelco a try.  
Still, I would be interested to know if anyone had tried the stronger spread spring solution asked about in the original question.  It was billed back in that old original post as maintaining good shift performance when the transmission was exposed to a life of ‘spirited’ shifting. 
 

Dennis

Toss your tranny in the mail, I put some fresh synchro’s in.  Never look back. Or learn to double clutch!

I even threw in some ARCHOIL in the last transmission to see if it would improve the noise level. Didn’t help. 

Edited July 20, 20231 yr by zKars

wrong entry

Edited July 21, 20231 yr by swflaz