700R4 Hard/Delayed 1-2 shift

[Girth]

1984 C10, 6.2 Diesel. New to me truck, and the trans and TC were replaced by the previous owner after the original trans gave up. (He said the replacement was out of like a '90 Burb)

So..... start out under moderate throttle/normal acceleration, seems to wanna stay in first for a WHILE, that diesel is winding up, but maybe only doing 20mph when in shifts. If I stay in it, that 1-2 shift is a fairly rough/hard. 2-3 shift is pretty solid too but not as hard, and everything after that feels just fine. I've gotten used to it sorta, so I'll let it wind up and if I lift off at the right time it will shift to 2nd with no load on it, and I can roll back into it without that hard shift.

As the truck comes up to temp, both the 1-2 and 2-3 shifts get softer, though the 1-2 is still noticeably harder and it likes to still hold 1st for a while.

I did some searching, as I'm pretty clueless on transmissions, and I kinda wonder if the previous owner got a bit sloppy reinstalling that throttle valve cable? Or maybe its a quirk I'm not used to? I've never had a 700R4, or a 6.2 diesel.

 

[NickTransmissions]

1984 C10, 6.2 Diesel. New to me truck, and the trans and TC were replaced by the previous owner after the original trans gave up. (He said the replacement was out of like a '90 Burb)

You likely have a standard governor causing shift points to be later when a diesel governor would be more appropriate for the diesel given their torque curve vs a 350 gas engine's.

You can pick up a Superior Tech governor kit to modify it so it shifts a bit earlier so it doesnt wind up the engine so much.

 

[Girth]

You likely have a standard governor causing shift points to be later when a diesel governor would be more appropriate for the diesel given their torque curve vs a 350 gas engine's.

You can pick up a Superior Tech governor kit to modify it so it shifts a bit earlier so it doesnt wind up the engine so much.

I was curious if it might be an issue with a gasser trans swapped into a diesel truck. Your reply explains that's a sure possibility, thanks. Any issue running it as is for now, without serious wear or damage to the trans?

I'll have to reach out to the previous owner, see if he has more info. He just said "Suburban", no mention whether it was diesel or gas.

Is that kit you linked something I can swap out with the trans in the truck? I don't see installation instructions on their site, though I'm sure I could call them for some guidance.

 

[NickTransmissions]

I was curious if it might be an issue with a gasser trans swapped into a diesel truck. Your reply explains that's a sure possibility, thanks. Any issue running it as is for now, without serious wear or damage to the trans?

I'll have to reach out to the previous owner, see if he has more info. He just said "Suburban", no mention whether it was diesel or gas.

Is that kit you linked something I can swap out with the trans in the truck? I don't see installation instructions on their site, though I'm sure I could call them for some guidance.

You can simply remove the governor from the transmission and do your mods to it with the kit on the bench; no need to remove the trans. The governor can be accessed at the rear of the transmission. Simply remove the governor cover retainer clip, if one is installed then take a smooth, flat blade screw driver and hammer and gently tap the back side of the cover off, working it all the way around. You want a small container underneath to catch the small amount of fluid that will come out.

Once done, you simply reinstall it.

I would grab a new governor cover square-cut rubber seal as well; the one on there may or may not be any good...

 

[Mike_82_Shortbox]

Before you try all that just try loosening up the throttle valve cable about 1/8 of an inch and see what happens.

 

[Matt69olds]

If you decide to mess with the govenor, I’d suggest getting a spare one to experiment with. That way if you screw something up you have a known good one to go back to.

Take detailed notes, make one change at a time. Depending on how picky you are with shift points, you might be done in a couple hours, or couple days.