'01 Suburban, 5.3L, 309K miles

Our old Suburban is starting to have issues with staying in OD. It's not entirely predictable, though...it might stay engaged for a while, then engage/disengage repeatedly for a long time, then it might just refuse to shift to OD entirely. All fluid levels look good. SES light's been on for a long time, but the husband services/maintains the vehicle himself and it's run beautifully until now.

We've been hoping to milk a few more miles out of it if possible (especially since it just had a $1K trip to a shop for a fuel pump during a road trip in November). I was hoping someone might have ideas on where to start before we lug it into a shop.

Any ideas?

Side note: I know it's a shot in the dark, but is there any way to check codes on these without a scanner? I know other vehicles - my little '02 Mopar grocery getter, for example - has a key sequence to read them. We're 20 miles from any place with a scanner (even just to purchase one).

 

Well, scratch that last stuff. The husband has decided he'd rather just put in a new transmission. I guess his rationale is he can find a used one in better shape than the one in there now with 309K+ on it, just to keep the old beast running for a while longer.

His next question to me today: what are the differences between a transmission for an '00 and for an '01? I think he's found one for an '00, and is wondering exactly what would need to be modified to make it work.

 

Salvage yards have an interchange manual that can provide that info. Might be online also.

 

Thanks, I know he checked everywhere in the nearest city but no one seemed to have it (the joys of living in BFE). I'll do some more poking around online and maybe give some salvage yards down south a call in the morning.