Teach Me About GM Overdrive Transmissions

I would think a 14-bolt would swap in easily.

Pay attention to: 1) Driveshaft length - is the 14 bolt longer or shorter than the Dana 70 and will the driveshaft slip/compress enough to compensate.

2) shock mounts - if the mounts are on the axles make sure they'll still work on the new axle.

3) brakes - make sure you account for how the hard lines will connect with the new axle. Don't forget to bleed the brakes. :)

4) spring perches - make sure they'll line up with your leaf springs.

With some good shopping and a slick sell of your Dana 70 I think you could come out ahead financial on this deal.

bravenrace wrote: In reply to Trans_Maro: Do you know the differences in fit? Can I put a 14 bolt in place of my 10 bolt? There is no identification on my axle.

I don't know the differences but if it's from the same truck it should swap with little modification.

Strange, "56" is cast into the snout of the Dana 56 in my '67 Jeep Gladiator and I've seen "44" in my Scout diffs but this site says it will be on the web by the cover:

A 14 bolt of the same width should fit and spring perches are easy to move if you have to.

Shawn

megasquirt oughtta have a crack at computer controlled trannys. Cheap 4l80's that nobody can really use is too big a travesty.

If the ''L'' trans are like the ''T'' trans, then a quick method to get a 4L80E (Wouldn't use a 60 behind a 454) to shift is to

A: Hook a 12V+ to the correct pinout that feeds the shift solenoids, fused of course.

B: Find the right pinouts for the 2 shift solenoids. Hook each wire to a separate toggle, and hook the toggles to a good ground.

That is all the controller does to shift. If I remember correctly, it goes a little something like this:

1st: off off 2nd: on off 3rd: on on 4th: off on

Then you set a third toggle to activate the lock-up torque converter once you are in 4th.

i picked up a 3.73 14 bolt from a 3/4 ton - there are lots out there that are under 4.xx gears.

any rear from 73-87 will pretty well swap in, might need to get the proper u bolts as some axles have different size tubes. may require a conversion universal joint depending on what you have. i put the 14 bolt in place of the corporate 10 bolt in my k5 and had to get a conversion joint as the 14 bolt had a larger yoke.

In reply to patgizz:

I think the 3/4 ton rear is a different width than the 1 ton dually, no?

I'm not patgizz, but I'll see if I can help:

from pirate4x4.com

Width - WMS-WMS (inches) SRW/DRW 67" C&C DRW 63"

1-tons feature 40.5" perch spacing - whether C&C or pickup, whether SRW or DRW. 3/4-ton is 42.5" spacing.

Interpretation: 3/4 ton and 1-ton axles are the same width. Leaf spring perches are wider on a 3/4 ton.

bravenrace wrote: In reply to Vigo: Is there any way to run a 4L80E without a controller?

I'm pretty sure that the diesel trucks (Suburban, Silverado) used a stand-alone trans controller in 1991 and maybe 1992. My memory is a bit foggy on the specifics, but I seem to recall that if you get/create the wiring from the trans to the computer and provide a few basic inputs (throttle position, speed signal, rpm) then you've got the controls taken care of. Google for specifics if you're interested in that approach.

Since you're obviously willing to put a bit of elbow grease into making this thing more tolerable, have you considered swapping fuel injection in while you're at it? If you go with a 454+4L80E computer from the TBI era (let's say 1993), it seems like it wouldn't be much more work and would probably be pretty cheap with junkyard parts. With that little bit of extra work you'd get better fuel and spark control, in addition to shift control, giving you better driveability and probably even better fuel economy. 1You'd have to get the engine+trans wiring harness, throttle body+intake, a few sensors (coolant, intake air temp), the newer distributor, and of course the trans related parts. If I'm remembering my 454 and 4L80 stuff right, this stuff should all be plug and chug bolt on stuff, no modifications needed with your older 454 long block. Of course, you'll need to get a complete wiring harness and "decontent" it, but some wiring will be required with any 4L80e swappery.

Bryce

a good friend of mine builds torque converters and automatic transmissions. he favors the 200R4 and has put them behind all sorts of engines, by splicing the bellhousings together. like 100mm+ turbo cars that run very deep 8s in the quarter. when pinks did all out at milan, i'm pretty sure both cars in the finals had Ridings Automatics in them.

^ What he said.

My auto trans guy has a contract with the local cab company.

When they stuff a 700-r4, it gets replaced with a TH-350 because they hold up better.

He says a 2004-R will take more abuse when built than the 700-R4 will.

Automatics are about the only thing I can't do myself, so I take his word for it.

Shawn