Got the '00 3500 home yesterday! I was out of time to deal with the replacement of the 6 speed, so a call to the dealer (and the bank) got things underway.
apparently, the 6spds (nv5600) are a little 'touchy' when it comes to proper and adequate lube. After disassembly, the tech at the dealer said the input shaft was welded to the mainshaft. (I saw it.....he wasn't kidding). they had to torch it out to remove.
*this is my 2 cents on overdrives here:* "poor idea" why?? a 'normal' gear box while in high gear (which is around 90% of the time) is all locked up. everything is turning as one. There are no 'gears'. Just the mainshaft 'straight through'. An overdrive on the other hand, while in od, every gear is turning at it's own speed. Can you imagine how fast 1st is spinning while driving @ 70mph+ ?? This where plenty of oil comes in.
The dealer wanted $3500 to rebuild my old NV. I found a trans shop in Memphis, http://www.highgeartransmission.com
that modified the case to hold more oil. Basically they drilled a higher fill plug in the case. It appears to be 2-3 inches higher than stock. they then just put a allen head plug in the old location, and put a square head plug in the new. It's supposed to hold 3 more quarts than the stock box this way. Just eyeballing the original location, IMO it was just below the mainshaft. Now it's just above.
I paid 2800 for the trans, plus shipping to the dealer. I got a 2 year warranty, and highgear pays for the return trip for the core. The man I talked to in Memphis has done about 150 of these, with no returns.
(If I can't break it......I will say this is the way to go.) time will tell.
According to him, there are a lot of parts in this trans that are not available OEM. but aftermarket pieces are plenty, and possibly 'tougher' than original.
I did have the option to 'upgrade' this trans to the bigger input shaft, but the clutch was just replaced less than 6 months ago. So, for now I am running the smaller shaft.
I am curious to see how much horsepower it will take to spin this new 'hydraulic pump'.... ie: fuel economy....
Back to the OD debate: why don't they do the od in the rear end, and have the trans geared (lower gears), lets say a 4 or 5:1 first gear, still have 6 spds all the way thru high (which would be straight through) but with a 3.23 rear end? But, on the other hand, while loaded, we would be back in 5th, and the trans is spinning like a top again. ( granted, less miles while loaded in 5th). sigh. I guess it's still better than a team of horses and a wagon!