LB7: Issues after LOw/reverse Clutch housing Crack

Wyatt

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Jun 3, 2016
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Not sure if I should post here or start a new thread so I guess I'll do both. I'm having a similar issue but I did have to replace the extension housing (Delco calls it the low/reverse clutch housing) U-joints went bad and the housing cracked when I moved the truck to my second driveway, it never got out of first during this move but the tranny fluid all leaked out, I started getting the Range Shift Inhibited message etc. Didn't have a code reader at the time but replaced the "extension housing (without pulling the Transmission), u-joint etc but still got the range shift message and the transmission doesn't engage at all. Replaced the NSBU unit, which didn't help and I replaced the ignition switch a few months ago due to another problem. I borrowed a code reader and found it had P0841, P0843 and P0848 codes. After I read the codes I cleared them and tried the transmission again but the codes didn't reappear but I'm still getting the "Range shift inhibited" message.

At this point I haven't torn down the front end of the tranny yet, just trying to get some advice so I don't miss anything when I do. I do want to say that the c5 clutch assembly did slide out when I took off the housing and I had to reinstall it, the diagram I had showed a clutch piston which wasn't in the transmission but I called up extreme diesel and they said their documentation didn't show one so I think I must have had a diagram for a different year or something.

I'd like to take it in but I'm really short of funds right now and have had some pretty bad luck with getting my truck repaired around here despite my efforts to find a good mechanic and have had a lot better luck fixing it myself. Never had any problems with it till the last year and a half and now it seems everything is going bad at once, brake and fuel lines rotted out had to replace all the calipers, electrical problems etc etc etc. I'm an organic farmer and those expenses plus the normal cash output I have to do time of year has put me in a real bind.

The code reader said the p0841 and p0843 codes were for the "A" switch and the p0848 was for the b switch but I noticed other sources listing the actual switches were the "C" switch for the 841 and 843 and the 848 referred to the D switch. I guess the A and b are for limp mode?

I'm guessing that when the fluid dumped the C1 clutch pak went, would that cause both the "C" and D solenoid issues? Most of the posts I saw only mentioned problems with the "C" I'm hoping the P0841 can be fixed with a cleaning of the "C" switch. I saw a chart on another thread that listed codes and said the p0841 was a C switch stuck open code and guessing there must be some clutch material doing that.

I know I'm not getting a definitive solution until I tear it apart and look at it, like I said just want to get my ducks in a row so when I'm in there I don't miss anything

Anyway its a 2003 LB7 2500hd 4wd 6.6L

Going out to drop the pan, should have done it already I guess


Thanks

Wyatt
 

Mike L.

Got Sheep?
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Aug 12, 2006
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Fullerton CA
You can not successfully replace extension housing while trans is in the ruck. Time to tear the trans down and see what slipped out of place.