Well, I'm an idiot

[AlanCasida]

When I put the 460PI/C6 back in my Galaxie i had a problem with the transmission. I has a full manual, reverse pattern valve body and while it was out I replaced the pump since the front bushing was all grooved up. Anyway, when I got it together I ran it while it was on stands and saw that when I shifted from low to second the speedometer would slow down then pick back up when I shifted to third.  couldn't figure out why it was doing this, I didn't take the trans apart, only removed the valve body and pump. I didn't want to drive it like that for fear of locking up the trans because it almost acted like it was starting out in drive instead of low. I removed the manual vb with a regular one and it would up shift ok but would not down shift by itself and after you stopped it would start out in drive unless you manually selected a different gear. So, I pulled the trans AGAIN and did some tests and took it apart but could find nothing really wrong. I replaced the sealing rings on the front pump thinking it could have been cross leaking through there. I put the C6 back in the car with the full manual vb and on the stands it did the same thing, the speedo would slow down when I shifted from low to second. Well this time I went and took it for a test drive and sure enough, it works just fine!! I'm an idiot! 

[cjshaker]

Alan, I must be an idiot also, because I'm lost...lol  Why would your speedometer slow down when shifting? Did you mistake the tach for the speedometer?

[AlanCasida]

That's what got me. When I put the regular vb in it upshifted just fine on the stands. The only thing I can figure is that full manual vb has no engine braking in low and maybe it needed a load on it to work right. Or maybe driving it is still masking another issue. I really need to just put the TKO600 back in it and forget about it.

[KMcCullah]

That's what got me. When I put the regular vb in it upshifted just fine on the stands. The only thing I can figure is that full manual vb has no engine braking in low and maybe it needed a load on it to work right. Or maybe driving it is still masking another issue. I really need to just put the TKO600 back in it and forget about it.

Curious which VB you're using? Is this with the R code servo?

 The Broader full manual VB that I've messed with runs the C6 like a true manual transmission. I've accidentally shifted back to 1st gear from 2nd at 7k rpm instead of catching 3rd gear. It almost wrecked me, it slowed the truck down so fast. I'm not use to being sideways at 90mph. Lol On pavement anyhow.

[AlanCasida]

That's what got me. When I put the regular vb in it upshifted just fine on the stands. The only thing I can figure is that full manual vb has no engine braking in low and maybe it needed a load on it to work right. Or maybe driving it is still masking another issue. I really need to just put the TKO600 back in it and forget about it.

Curious which VB you're using? Is this with the R code servo?

 The Broader full manual VB that I've messed with runs the C6 like a true manual transmission. I've accidentally shifted back to 1st gear from 2nd at 7k rpm instead of catching 3rd gear. It almost wrecked me, it slowed the truck down so fast. I'm not use to being sideways at 90mph. Lol On pavement anyhow.

I am using a Broader full manual vb without low gear engine braking. I may have another issue going on that I didn't know about. When I ran the car on Dragweek I noticed the trans was running hotter than I thought it ought to. So there may be something else going on. This is a home built C6 by me and it was my first try so that may be a factor.

[KMcCullah]

That's what got me. When I put the regular vb in it upshifted just fine on the stands. The only thing I can figure is that full manual vb has no engine braking in low and maybe it needed a load on it to work right. Or maybe driving it is still masking another issue. I really need to just put the TKO600 back in it and forget about it.

Curious which VB you're using? Is this with the R code servo?

 The Broader full manual VB that I've messed with runs the C6 like a true manual transmission. I've accidentally shifted back to 1st gear from 2nd at 7k rpm instead of catching 3rd gear. It almost wrecked me, it slowed the truck down so fast. I'm not use to being sideways at 90mph. Lol On pavement anyhow.

I am using a Broader full manual vb without low gear engine braking. I may have another issue going on that I didn't know about. When I ran the car on Dragweek I noticed the trans was running hotter than I thought it ought to. So there may be something else going on. This is a home built C6 by me and it was my first try so that may be a factor.

Ah gotcha. I didn't realize low gear engine braking was an option. It would have saved my sideways episode. These C6's are truly bulletproof.

Have you double checked your shifter? Verified one shifter click equals one tranny click?

[427mach1]

I've got an A-1 manual valve body reverse pattern C-6 that I bought in 1997.  It has the "no engine braking" in 1st gear, which I believe is just a one-way sprag.  Kind of surprised me the first time I downshifted to first gear and the engine dropped to idle, very similar to pushing the clutch in on a manual transmission.

[wcbrowning]

What is the purpose of setting up the transmission to have no engine braking in 1st gear?

That's what got me. When I put the regular vb in it upshifted just fine on the stands. The only thing I can figure is that full manual vb has no engine braking in low and maybe it needed a load on it to work right. Or maybe driving it is still masking another issue. I really need to just put the TKO600 back in it and forget about it.

I've got an A-1 manual valve body reverse pattern C-6 that I bought in 1997.  It has the "no engine braking" in 1st gear, which I believe is just a one-way sprag.  Kind of surprised me the first time I downshifted to first gear and the engine dropped to idle, very similar to pushing the clutch in on a manual transmission.

[machoneman]

What is the purpose of setting up the transmission to have no engine braking in 1st gear?

Well, it would be like hitting reverse in a stick car after a 120 mph run! To the point, accidently clocking down into 1st with any auto tranny at that 120 mph by accident will spin you in a hurry!

[Falcon67]

Interesting - no C4 manual that I know of has engine braking in 1st.  I actually don't think mine has any engine braking at all.  Not a problem for me anyway.  And, my car hasn't had a speedo cable in it in 20 years.  I just use the tach. 

[plovett]

My manual C6 has engine breaking in first.  I am not sure if would choose that again next time or not.  It works fine though.

paulie

[gt350hr]

   Engine braking in low gear comes from the band being applied. MANY reverse manual valve bodies do not apply the low/reverse band as it isn't necessary in a drag race situation and slows release of low gear on the 1-2 shaft causing overlap that hurts clutches and bands.