Back in the early 90's I did the modification with using an A servo piston, without the O-ring on the outer piston, with an H servo cover. Then plugging the vent hole. I was using it with a valve body that I used the old B&M Manual-Pak kit to convert to a full manual, but still forward pattern, valve body. Never ran into problems with it locking up on me, but I was pretty particular on my maintenance and usually pulled the transmission out in 100 runs to freshen everything up, so there was not time for the seals to harden up. Where I DID have problems is that thin portion of the gasket, near the now plugged vent hole blowing out. Cost me $800 in a final round back in the late 90's. Made a girdle to surround the entire servo cover, with a set screw right over the weak spot of the gasket. That cured the problem, but never trusted the setup again, so I purchased an aftermarket servo. Quite honestly, I never noticed any difference between the H servo, my modification and the aftermarket one and was probably just as well off continuing to use the H servo. Where I DID have problems with it locking up in high gear was when I started to make a little more power, about 1986 with my '68 Mustang. I was still using the factory shifter with the solid shifter rod. The valve body at that time had just a standard B&M shift kit of that time period that had 3 different stages of modifications. The car was probably starting to flex and was pulling on the high gear detent. My memory from almost 40 years ago is not very good, but I think at that time I studied the hydraulic diagram and determined it was possible to leak pressure to start to lock up the low/reverse band if that happened. I DO know that I ended up skidding in the grass and was probably lucky that the car wasn't faster than it was. Bought an aftermarket shifter with a cable and also bought that B&M Manual-Pak at the same time and never had another problem.
Yes I used a B and M Manual -Pak back in 1976 in a 65 Mustang. But I did it for mountain driving so I could control the down shifts for engine braking going down grade. Kind of a hard shift but worked fine. I just followed the instructions.
@@GaryH-pw9cm They worked great for drag racing. Good firm shifts and no flare. Came with all the jigs to make the modifications and very complete instructions. I used that valve body for a lot of years and it is still in my shed somewhere.
Thank you Jay. Appreciate the video and knowledge shared. For all the viewers that read the comments.... Ive had a problem weather i.tried the Sonnax R code or Superior R code , both with E code lever. And not sure wich spring is in there for either brand. This could be my issue. The issue is a hard downshift when coming to a stop. I believe its a 2-3. And 3-2. Bind. Dosen't always do it. But happens more often than not. Im definitely going to check this out. My original servo was S code and A lever from the factory. Im second owner of this 77F250 4X4. I know the Original owner had a shit improvement kit installed back in the 1980'S. Anyhow, now i have something to inspect. Edit-- i just checked my situation, im running the Superior R Servo , and E Lever. I had the Heavy Superior spring in there. Replaced it with the FACTORY/OEM GREEN SPRING. Basically fixed 95% of my hard downshift/binding/ chirping the tires when coming to a stop. Or the driveline binding when rolling down the street and it shifts from 3-2. The Factory Green Spring is THE WAY Too GO. In my application. I do have a shift kit in the valve body. But don't know wich one. It's been in there from the original owner. And I bought the truck in 1994.
JAY IS RIGHT , The Factory Green spring is the way to Go Im using the Green spring with Superior R code Servo and E lever , thats what I'm running in an Autoshift C6. Whatever shift kit that's in there is what I'd call a FIRM Shift. The Superior Heavy spring was causing me problems. Ive tried the Sonnax R Code servo with Heavy spring and it also caused the same problem. The Factory/OEM Green spring fixed my issue. Read my other comment on this video.
Sonnax and Superior R Code servos for the C6 both have the o-ring. I will be running your C6 auto shift VB and just want to make sure I should be removing the o-ring in my Supeior R Code servo? Thanks again for putting your experience and knowledge out here for those of us wanting to learn the art of these antique transmissions.
Just looked at my Sonnax C4 "C" servo, and it doesn't have the o-ring, rather the body has a slight step on the od, and a notch in the side just like your mod. Love the videos, keep them coming! Btw I'll be in touch to order a stall converter for my c4 to go with your transbrake i just bought 👍
Looking good Jay, thanks for keeping us safe.
You bet
I enjoy all your Intel on these units.
Back in the early 90's I did the modification with using an A servo piston, without the O-ring on the outer piston, with an H servo cover. Then plugging the vent hole. I was using it with a valve body that I used the old B&M Manual-Pak kit to convert to a full manual, but still forward pattern, valve body. Never ran into problems with it locking up on me, but I was pretty particular on my maintenance and usually pulled the transmission out in 100 runs to freshen everything up, so there was not time for the seals to harden up. Where I DID have problems is that thin portion of the gasket, near the now plugged vent hole blowing out. Cost me $800 in a final round back in the late 90's. Made a girdle to surround the entire servo cover, with a set screw right over the weak spot of the gasket. That cured the problem, but never trusted the setup again, so I purchased an aftermarket servo. Quite honestly, I never noticed any difference between the H servo, my modification and the aftermarket one and was probably just as well off continuing to use the H servo.
Where I DID have problems with it locking up in high gear was when I started to make a little more power, about 1986 with my '68 Mustang. I was still using the factory shifter with the solid shifter rod. The valve body at that time had just a standard B&M shift kit of that time period that had 3 different stages of modifications. The car was probably starting to flex and was pulling on the high gear detent. My memory from almost 40 years ago is not very good, but I think at that time I studied the hydraulic diagram and determined it was possible to leak pressure to start to lock up the low/reverse band if that happened. I DO know that I ended up skidding in the grass and was probably lucky that the car wasn't faster than it was.
Bought an aftermarket shifter with a cable and also bought that B&M Manual-Pak at the same time and never had another problem.
Good info. Thanks for sharing
Yes I used a B and M Manual -Pak back in 1976 in a 65 Mustang. But I did it for mountain driving so I could control the down shifts for engine braking going down grade. Kind of a hard shift but worked fine. I just followed the instructions.
@@GaryH-pw9cm They worked great for drag racing. Good firm shifts and no flare. Came with all the jigs to make the modifications and very complete instructions. I used that valve body for a lot of years and it is still in my shed somewhere.
Thank you Jay.
Appreciate the video and knowledge shared.
For all the viewers that read the comments....
Ive had a problem weather i.tried the Sonnax R code or Superior R code , both with E code lever.
And not sure wich spring is in there for either brand.
This could be my issue.
The issue is a hard downshift when coming to a stop.
I believe its a 2-3. And 3-2. Bind.
Dosen't always do it. But happens more often than not.
Im definitely going to check this out.
My original servo was S code and A lever from the factory. Im second owner of this 77F250 4X4.
I know the Original owner had a shit improvement kit installed back in the 1980'S.
Anyhow, now i have something to inspect.
Edit-- i just checked my situation, im running the Superior R Servo , and E Lever.
I had the Heavy Superior spring in there.
Replaced it with the FACTORY/OEM GREEN SPRING.
Basically fixed 95% of my hard downshift/binding/ chirping the tires when coming to a stop.
Or the driveline binding when rolling down the street and it shifts from 3-2.
The Factory Green Spring is THE WAY Too GO.
In my application.
I do have a shift kit in the valve body.
But don't know wich one. It's been in there from the original owner. And I bought the truck in 1994.
JAY IS RIGHT , The Factory Green spring is the way to Go
Im using the Green spring with Superior R code Servo and E lever , thats what I'm running in an Autoshift C6.
Whatever shift kit that's in there is what I'd call a FIRM Shift.
The Superior Heavy spring was causing me problems.
Ive tried the Sonnax R Code servo with Heavy spring and it also caused the same problem.
The Factory/OEM Green spring fixed my issue.
Read my other comment on this video.
Sonnax and Superior R Code servos for the C6 both have the o-ring. I will be running your C6 auto shift VB and just want to make sure I should be removing the o-ring in my Supeior R Code servo? Thanks again for putting your experience and knowledge out here for those of us wanting to learn the art of these antique transmissions.
I dont use that oring but its probably not an issue if you install it.
Just looked at my Sonnax C4 "C" servo, and it doesn't have the o-ring, rather the body has a slight step on the od, and a notch in the side just like your mod.
Love the videos, keep them coming! Btw I'll be in touch to order a stall converter for my c4 to go with your transbrake i just bought 👍
Thank you. We appreciate the business.
My Sonnax C4 servo has lip seals. I guess they are better than O rings. I really don't notice anything different during shifts.
Thanks for the video. Good info.
Glad it was helpful!
great info.
Glad it was helpful!
Thanks
Welcome
None of the Dynamic valve bodies use those mods either.
I think it's a good thing when the customer doesn't also have to mess with the servo just for a valve body swap.