It might depend on the truck. The 90's chevies are I think only NV3500 and NV4500, and i'll agree with the other poster - the 3500 is pretty light duty and also used in the lighter S10/Colorado but shouldn't be hard to find a replacement for or redo. The 4500 is a bit rare, but is a great transmission. Whether the 700R4 sucks might depend on your usage - anything that lasts 150,000 hard police miles and another 350,000 taxi miles in those Caprices of the same era which is where countless 9C1 Caprices ended up and is still running isn't ALL that shabby in my book... the same in a light duty truck as opposed to heavier unless subjected to abusive over-limit towing should probably be fine. Many light duty truck buyers treated them like cars afterall. By about 1992 I thought all the quirks of the 700R4 had been worked out in other cars shortly before the change to the electronic 4L60E version which is arguably the same trans - the later years of 700's are the best if you get one, the 4L60's should have all mechanical lifespan fixes already learned.
If youre not only looking at Chevies i'd wait for others to respond who probably know more but I thought those Ford ZF5 boxes were alot more common and hailed as million mile transmissions? The Dodges I just dont know about offhand other than the NV4500's in the 3/4 and 1tons being pricey to replace again.
You can certainly find replacement autos easier in the junkyard alot of the times, although it's a bit oversized for lighter work i'd almost think a 4L80 could probably be made to work (i'm not an expert on the swap but pretty sure they could be found in 3/4 tons not just 1 tons) which i'd think would be tough enough to last forever - swap once and not need to again. It would parasite more power with the weaker engines would be the only downside I could think of since its like the TH400 really sized for a big block or a turbodiesel more. It'd make a nice match to a more powerful LS even the 4.8 with 285hp or so if you ever swapped an engine later too. However the 4L80 also has some electronics to control shifting/not all hydraulic like the 4L60.
If you just need a beater esp a GM, an auto trans would probably be a good way to go based on the choices from the 90's - in addition you never know if a clutch is about to die in a stick shift (not that i'm aware of? unless people are aware of signs i'm not) whereas an auto usually passes the "if the fluid is pink and no stink" test it's good for at least a good while more.
Originally Posted by Rmay635703
On my diesel Suburbans I would just swap out the auto when it failed for a stick, fit the hydraulic clutch pedal and put in a caddy rear end and never look back, best $350 investment for $$$ savings.
Whats this about Caddy rear ends now? Just curious hadn't heard of that swap and was wondering what purpose it was for..
