Slight performance build on a 518

Knoberman said:
I like my 1-2 shift, but my 2-3 shift is too quick, I think I had a different servo spring but not sure, how would one go about changing that? 3-4 is really good, if I could get 2-3 right I'd be happy.
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What do you mean by the shift is too quick?does the engine free rev for a second? Or does it hesitate, and kind of slow down?? The later of the two is a overlap (not good) and the earlier is a shift flare.

Or does it shift gears really hard and firm like it's going to chirp the tires? Is that what you mean by too fast? I know I'd rather have a firm fast shift than any other. Transmissions seem to last longer that way. But you don't want a bang box, not only is it annoying, it can prematurely wear out parts.
 
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Oh so the shift happens too soon in the rpm. I've noticed adjusting the tv cable has a larger effect on the 2-3 shift, more so than the 1-2. I would try adjusting the tv cable to give you a little later of a shift.
 
If you ever have your transmission rebuilt by a shop make sure they have dealt with diesels before. I had a guy that knew a lot about Chrysler transmission build mine once. Only problem was when I told him I want it built for performance, he set it up internally for a high revving gas motor. My old transmission would shift WAY too late. I had to run the tv cable more loose than I wanted. Ended up dissatisfied with the build. But hey, you gotta learn.
 
He is saying there is a screw to adjust line pressure on the driver side of the vb.
Counter clockwise is more pressure til you press the spring all the way out
 
My shift kit adjusted said screw. I'm curiouse as to how much more I could turn it out? Another 5 mph added to my 2-3 shift would be ideal.
 
91shelbydaytona said:
No he is talking about the part throttle upshift screw... I believe every turn in raises it 75 rpm if i remember correctly
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Where would that screw be? i build these weekly and never heard of such a thing.

There is a screw that sets min/base tv pressure, but none that i know of that will adjust part throttle upshifts. The other sets line pressure.
 
Yes, the min/base tv pressure screw, it is also known as the "throttle valve stop". I have an older bd instruction sheet that says right on it 75 rpm change per turn

Right off of bd's current valvebody install instructions:
Kick down cable adjustments are for Full Throttle shift points &
passing gear only. Light Throttle shift points should be adjusted
on the valve body throttle valve stop.

http://www.xtremediesel.com/manuals/1030416.pdf

Keep in mind this will change 1-2 and 2-3 shift points both but its worth a shot
 
Thats doing the same thing as tightening the tv cable. It will raise idle/no throttle pressure, but then you would have slack in the tv cable if you dont tighten it a little as well. As soon as you are in the trottle that stop has no effect so i dont see how it will change part throttle shift points unless you adjust the tv cable as well.
 
mathews8pt said:
Thats doing the same thing as tightening the tv cable. It will raise idle/no throttle pressure, but then you would have slack in the tv cable if you dont tighten it a little as well. As soon as you are in the trottle that stop has no effect so i dont see how it will change part throttle shift points unless you adjust the tv cable as well.
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Makes sense to me. All that would do is adjust the base tv cable input. I dont see that adjustment holding his shift longer at wot.
 
I just put together a 48re valvebody for a guy with a transgo kit. After he drove it he wanted to lower the shift points a couple hundred so I backed that screw out two turns based on the bd instructions. I swear it lowered them and I never even touched the tv cable adjustment. Maybe it was coincidence lol. Ive built quite a few of these valvebodys but thats the first time ive ever adjusted that.
 
91shelbydaytona said:
I just put together a 48re valvebody for a guy with a transgo kit. After he drove it he wanted to lower the shift points a couple hundred so I backed that screw out two turns based on the bd instructions. I swear it lowered them and I never even touched the tv cable adjustment. Maybe it was coincidence lol. Ive built quite a few of these valvebodys but thats the first time ive ever adjusted that.
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I can see backing the screw out as a way to lower shift points, if the tv cable has slack in it already. Thats not a great idea though because you are slowing down the pressure increase, which could cause a problem if the truck gets lugged around a lot.

Ive done quite a few transmissions and still learn everytime i have one apart. This is a great place to bounce ideas off each other and learn.:Cheer:
 
Knoberman said:
Anyone know of a upgraded reverse band anchor, I lost reverse again this morning.
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Sure you arent having an issue with the servo being cocked in the bore or broken? I would check your pressure at the rear servo and see if you have anything. Patc sells upgraded rear servos to possibly prevent issues.
 
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