Very soft shifting 727

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Very soft shifting 727

Postby shackwrrr » Sun Mar 08, 2015 1:18 pm

Just brought my truck home and this is the first diesel I have ever driven with a 727. I have noticed that it is very soft and under normal acceleration you can't see or hear the shifts. Under WOT I get a slight exhaust note change but no RPM drop, much like a CVT transmission.

If I shift it manually, I get nice firm quick shifts and I don't get any shudder or signs of slipping.

Is the torque converter just that loose in these things?
1991 w250 RCLB
3 speed auto Non IC truck
shackwrrr
fuel screw!!!!
 
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Joined: Mon Mar 02, 2015 5:47 am

Re: Very soft shifting 727

Postby Philip » Sun Mar 08, 2015 7:10 pm

Not that loose. Check your throttle valve cable. It is most likely out of adjustment or disconnected. This cable is also known as the kick down cable.

To adjust it there is a white clip on the cable mount up by the engine. Lift that clip up. Slide the cable in or out to set the travel. I normaly start with 1/16" between the throttle linkage arm and the TV cable slider. Just keep setting the TV cable till the trans shifts the way you want it to. Most of the cables I havbe adjusted like it with no free play between the pin and slider.

Here is a pic of the linkage. This is a little different than yours. This linkage is from a intercooled truck. The adjustment is the same between them.

Image
93 W350 Club/cab w/duals, buckets & console, B&W flatbed, G56, 6 spd, 3:07 rears, gages, HX40/16, 4" exhaust, 6X.018 sticks, rear air ride suspension
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Philip
14mm rotor
 
Posts: 1954
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Location: Indiana

Re: Very soft shifting 727

Postby shackwrrr » Mon Mar 09, 2015 7:37 pm

Thanks, checked it out and the cable was pinched around the starter and popped out of the bracket at the trans. Re routed it and added a zip tie and it does a lot better. Has about .5 in of travel with the throttle held WOT, going to tighten it up a bit.
1991 w250 RCLB
3 speed auto Non IC truck
shackwrrr
fuel screw!!!!
 
Posts: 34
Joined: Mon Mar 02, 2015 5:47 am
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Re: Very soft shifting 727

Postby Philip » Tue Mar 10, 2015 5:57 am

Don't worry about WOT travel. TV adjustments are done at idle position. Set the trans shifts to 8/12 MPH for 1st to 2nd gear upshift. 2nd to 3rd should be 18/22 MPH. That is a light throttle take off for the shift points. That means just enough throttle to move the truck.


I would recommend doing a fluid/ filter/ band adjustment. No telling when the last one was done.

WOT in 3rd you should hit around 85/88 MPH. If it doesn't. Adjust your throttle linkage to get full throttle. A lot of the trucks were improperly adjusted from the factory. Even today a lot of the trucks have not been adjusted properly.
93 W350 Club/cab w/duals, buckets & console, B&W flatbed, G56, 6 spd, 3:07 rears, gages, HX40/16, 4" exhaust, 6X.018 sticks, rear air ride suspension
User avatar
Philip
14mm rotor
 
Posts: 1954
Joined: Mon Jan 08, 2007 10:50 am
Location: Indiana
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