C6 shifting

[BKahler]

Still getting used to how my new truck drives and shifts. When I drove it home pulling the loaded trailer I didn't notice any shifting issues. However, driving the truck around town with no load the shifting seems a little harsh. Not sure if this is normal or not.

The only information the seller had for me was that he had it rebuilt in the last year or so and when he did he supposedly had them put in a heavier duty torque converter. However, I've learned to never trust what the seller says, its usually true but not always.

Any idea as to whether the tranny might have some hidden problems?

Oh yeah, the truck has around 170,000 on it.

Brad

 

[Agnem]

He may have upgraded the clutch packs. Firm shifts are good. That means there is less slipage going on, and the clutch discs will last longer.

 

[BKahler]

He may have upgraded the clutch packs. Firm shifts are good. That means there is less slipage going on, and the clutch discs will last longer.

That makes me feel a little better. I'll try and get a hold of the guy and ask if he had them do that. Its definitely not a real harsh slam into gear or jerk, or anything like that. Its just that you "notice" the shift more than in other vehicles. I'll see how the tow goes tonight with the horse trailer.

Thanks for the info

Brad

 

[DeepRoots]

you have to remember the c6 is old technology.
the only auto trans I've ever had was a c6..... 200k miles or more.

anyway, I've always found that accelerating hard, letting off, accelerating hard, letting off, gets the best shifts.
has to be a by feel kinda thing.
1-2 is rarely a hard shift, it is normally 2-3.... just a slight feathering on the go pedal will get a really soft shift, since the trans isn't under as much load.

 

[beretzs]

You can test your Vacuum Regulator Valve on the side of the IP. If that is not set properly you will get hard shifts or soft shifts. You need a Vacuum pump and a guage, but setting it is very easy and worth the time to make sure the tranny is shifting correctly. Scotty

 

[BKahler]

You can test your Vacuum Regulator Valve on the side of the IP. If that is not set properly you will get hard shifts or soft shifts. You need a Vacuum pump and a guage, but setting it is very easy and worth the time to make sure the tranny is shifting correctly. Scotty

Thanks for the info on testing the Vacuum Regulator Valve. I've got a mighty vac I can use. I just received my ebay obtained copy of the Electrical & Vacuum trouble shooting guide. I'll read through the manual for the details. During our trip to Ohio and back the shifting didn't seem to bad to me but my wife feels it a little harsh. We'll see....

Thanks,

Brad

 

[dbensen]

I have adjusted both my C6 VRV valves to the factory spec. found the shifting to ba a little late and harsh. I used the factory setting as a starting point and moved the VRV slightly to get the feel I was looking for. While talking to a Transmission Tech. at the dealer he found the the factory setting can be harsh depending on what you are used to. The vacuum modulator may have an adjustment screw, mine did, when you remove the vacuum line. He said that you have about nine turns each way to fine tune the shifts. Backing the screw out will cause it to shift earlier. He said start with two turns and see what that does but remember how many turns just in case you want to go back. By the time I had talked to him I had spent about an hour and countless trips up and down the street to check it. Finally found the sweet spot. I should hook up the guages again and see what the readings are with the .515 guage block that Ford calls for. Hope this helps and keep us posted.
Good luck,
Doug
'86 F-250 4x4
'89 E-250 ATS