So since I had my transmission rebuilt (under 4k miles ago), it's been feeling really 'loose'. Best way I can describe it would be to compare it to manual in first, and taking too long to drop the clutch. The RPMs go way up, but it just doesn't 'catch' when it should. I floor it and it takes a while to actually transfer the power to the wheels.
Wanted to find out if there was anything I can do to adjust it, without pulling the whole tranny. My buddy was saying the bands might be loose, but I don't know how to go about adjusting them...
The shop wasn't able to spot it because my CAT was burnt and clogged my exhaust up. My truck was having enough trouble moving. I can't take it back under warranty because I moved 300 mile north of where I had the work done.

Thanks again folks!

 

If the bands are slipping the trans is toast. The fluid will be burnt black.

Most likely the new trans has a higher stall torque converter than the stock one. That will do exactly what you are describing.

 

If the bands are slipping that doesn't mean the trans is toast. Band adjustment is supposed to be check every 15,000 on the C-series transmissions. First I would call the shop and tell them you are having problems. Find out if they put a high stall converter in. Get your converter fixed and if it still isn't driving correctly make sure you get in touch with that shop. If it needs towed they should pick that tab up. You have a warranty take advantage of it. If you so desire to adjust the bands, here's how to do it. Loosen the crush washer on the on the adjustment screw (left side of case). Tighten the band screw to 10 ft-lbs then back it off 1 1/2 turns. With the washer being new you should be able to tighten it back on with no leaks. That's for the intermediate band. There is no adjustment for the low/reverse. That's why I would be contacting the shop.

Matt

 

There is only 1 band in a C-6.

 

If a C6 band really needs adjusting the band or drum is toast! The friction material on the C6 band is only about .030" thick. The band is only used in 2nd gear and would have no effect on 1st gear driveaway anyhow.

 

I'll call the shop this week and see what all they did, warranty wise, I'll have to check, since the shop is across the state. I'm not messing with the band until I talk to them, so I'll keep you folks updated. Any more info will be a great help.

 

It sounds more like a leaky slipping clutch pack.

 

I haven't had the chance to call the shop, usually I'm working the same hours, but I tightened up the band when I had a few minutes a couple of days ago. It's a night and day difference. It's shifting well now, and has a lot of pick up. I also checked the fluid, and it isn't toasted. If anything else comes up with it, I'll let you folks know. Thanks for the help!

 

Hey bub.
have not ssen you lurking around. Wasa reading about the ride. Too bad. Glad you checked in before you ran that thing to an early grave. Even more glad to hear you got it resolved.
Good job.

 

It's mostly resolved. It still seems to start slipping a bit after I drive it a while and it warms up. If I shut her down and let sit for a while, it shifts fine. I just got another truck, so when I have time and place to work on it, I'm going to pull the tranny, and ship it to the shop that rebuilt it for another rebuild under warranty.

 

Well, the tranny was pulled and rebuilt in a shop a few months ago. The torque converter looked pretty toasted and the fluid got all burned up. The same shop rebuilt it under warranty, and the builder told me to just run it to an auxiliary cooler instead of through the radiator.

I just got most of the motor bugs finished, and am finally able to drive the ol' girl around again. Since the rebuild though, it won't shift down to 1st gear when I'm in D. Just starts in 2nd and shifts to 3rd. 1 still puts it in first, and 2 still puts it in second. I've already adjusted the modulator in 4 turns to see if there would be any difference, but there isn't.

Any ideas where to go from here?

 

I cant believe you have been dealing with this since Christmas!

Anyway if you are having second gear starts the problem is in the governor. This can be a common after rebuild problem because the debris from the last failure is in the cooler and lines if its not flushed well. As soon as the new fluid flushes out the debris it sticks the valves in the governor.

Remove the tail housing and the governor (held on with four 3/8 bolts) and clean until both valves move without the spring pressure.

 

Yeah, this truck has been a constant nightmare since I first got it...

If the problem is in gummed up valves, I'm going to give the seafoam trans additive a shot before pulling anything. It fixed the problem I was having with my T-Bird (late R, no 3rd) and saved me from doing a rebuild.

I'm just trying to stay away from dealing with the governor because it is a 4x4 with a married case, and that is HELL to pull. I did my best to make sure the governor did get thrown off when I installed the T-Case, and blew out all lines with 120 psi compressed air.

Thanks a ton for the info...

 

This is likely an OK thing to do in California since you're not going to encounter any really low temperatures but it is possible to overcool an automatic.

I worked with some heavy duty towing situations when I worked for a seed company. We had bought a used 460 C6 that came with 3.08's. We sent the truck to our Nebraska research station along with a set of 4.10's and instructions to change the ratio before towing the monstor heavy wind-anchor loads we pulled. They didn't and fried the tranny. When rebuilt the shop installed a large aux cooler, bypassed the radiator cooler/heater, and left the 3.08's. The following year this truck was up in Wisconsin during a -30* stretch and literally froze the fluid, no lube = killed another C6.

I've towed my 5th wheel in triple digit temps (as high as 111*) and before the modification saw tranny temps as high as 240+. I now have two OE type plate coolers, a 24 plate and a 27 plate, in series right after the tranny and then run the fluid through the radiator. I seldom see tranny temps that exceed coolant temps but always in that range. I also believe this routing has dropped my engine coolant temps, most likely simply from reducing tranny fluid temperature before it hit the radiator.

Just a caution to anyone who may be thinking about bypassing the transmission cooler/heater part of their radiator in a cold climate.

 

You'd be surprised. Low single digit temps are not uncommon in the populated mountain area around Tahoe. I know it's no Minnesota, but I don't think it's ever a good idea to completely bypass the radiator cooler for a tranny.

It should always go: tranny -> external cooler -> radiator -> tranny.