1983 chevy SWB Rear end

[tthornt]

Hey all! - I going to install rear end (3.08)
Can some one please advise as to the degree of difficulty as well as where do begin?

Thanking all in advance
Tony

[Pop's C-10]

tha whole rear end or gears

[tthornt]

tha whole rear end

[nbpro]

Least amount of problems would be 82-87 Pickups with 10bolts and 88-91 Suburbans. (2WD if yours is a 2WD)
73-81's will work, but you have to have a hybrid U-joint.
but dont quote me on that

[tthornt]

Gary,
Thanks for the reply and the info.
I'm installing a 10 bolt rear (3.08) out of an 84 chevy swb. I'm removing a 10 bolt (g80 that has a set of 373's limited slip)

Tony

[Walts_restoration]

why ya swapping 3.08s for 3.73s? Bring me that 3.73 rear and ill put it under my 3.08 truck! haha.

Shoudlnt be that hard. When we did my camaro (Same 8.5 10 bolt) we simply popped the cover, pulled jungle pin bolt and c clips then slid axles out, unbolted the brakes, then housing out, new housing in, brakes back on followed by reinstalling axles c clips jingle pin and cover. My brakes were good on my car and the new axles backing plates were a little rough. It should be a relatively easy swap any way you go about it. Dont crimp the brake lines though.

[tthornt]

Swapping out for hywy gears and better gas mileage (hopefully)
I'm running 283 sb w/a th-375 (same as a th-400) the 400 is going away as soon as i have my th-350 rebuilt.

Tony

[Walts_restoration]

th375 a or b? one is a th350 with a 400 output, and ones a th400 with a 350 output, pretty neat to me. I assume the th400/350 output.

With a 3 speed no overdrive you should love it. i leave my truck in 3rd (1:1 most of the time) with my 3.08 gears and 235/75/r15s. With the 700r4 and 3.08s overdives almost useless.

[tthornt]

th-375/400 w/ th350 shaft, running 255-70-R15's. i've hearing that i will not have better gas mileage until i install a 700r (which is not an option). I think i'll get better gas mileage w/ the 3.08's, 283sb, and the th400. i just need to install the 3.08 rear end.

Tony

[nbpro]

get better gas mileage with the 3.08 yes you will

[454HO]

I just did a rear end swap a couple weeks ago. Went from 2.73 to 3.42 gears.

Procedure is pretty easy. Here is the way I did it:

1. Jack up truck and support with heavy duty jack stands
2. remove wheels and I remove drums too
3. unbolt the driveshaft at the rear yoke
4. unbolt shocks from axle tube
5. disconnect and plug the hydraulic brake line. It would be a good idea to get a new hose.
6. disconnect the parking brake cables. How you do this depends on whether you plan to reuse the original cables or if the new rear end has cables you want to use. To reuse your originals, you will need to completely disassemble the brakes all the way to the backing plates and then remove the cable end. If you are using the cables on the new rear end, then you need to disconnect both cables from the adjusting bracket that is just in front of the drivers side rear wheel.
7. unbolt the 2 U-bolts on each side. Have a floor jack supporting the rear end so it dosn't drop. Then drag it out.

Reverse to install new rear. Don't forget to bleed the brakes. It too me about 4 hours to do mine, but I was in no rush. But also none of my bolts were rusty or stuck. It may be a good idea to spray penetrating oil on all the bolts at step 2 so they have time to soak while you wrestle the parking brake cables.

Good luck, and put me in line for that 3.73 rear if you decide to get rid of it.

[454HO]

Couple other things I forgot to mention. I assumed you have not lowered your truck with a flip kit. If you have, then there is an extra step of unbolting the springs at the rear shackles. Also, there are 2 sizes of drum brakes. Easiest way to identify is to measure the width of the brake shoes. Light duty bakes have 2" wide shoes, and heavy duty brakes have 2-3/4" wide shoes. You cannot mix and match the brake parts because the drums are also slightly different diameters.

In my case, the original rear end had light duty brakes. The 3.42 rear end that I swapped came from an '88 Suburban and it had the heavy duty brakes. I used the parking brake cables that came with the new rear, so I don't know if the originals would work or not. The larger heavy duty brakes do have more stopping power and are desirable if you have them. So if your original rear has HD and the new rear does not, you might consider swapping them.

And one last thing... I highly recommend removing the rear cover on the new rear to drain the old gear oil. Make sure it has never had water in it, and inspect the gears inside for chipped teeth, rust, etc, etc. I passed up several rear ends when I was looking for one because they had water in them.

[Dru]

lol, wish I had a turbo 400, and a limited slip 3.73 under my truck before I started, that's the good stuff, but 3.42 would have been better.

The swap is pretty easy, but finding another G80, with a 3.08 in it, might be a little tough, unless you dont mind a one legger?

Would be half tempted to find a different ring and pinion.

Swapping out the th400/373 to a th350 should gain you a little mpg also, it takes more power to turn a 400, but the amount might be so little, that it isn't very noticeable.

[LONGHAIR]

Originally Posted by Dru

Would be half tempted to find a different ring and pinion.

That is a far more technical and expensive way to go. A simple swap of the entire housing is a much better way to go for the majority of truck owners.

[tthornt]

Hey all - I appreciate & thank your for the advise.
With my current setup th400 W/3:73 the truck is straining for another gear (feels like something is holding me back) and my RPM is over 2-grand.

Greg, U are the first one on the list for the rear. Perhaps we can hook up after the holidays. BTW Thanks for the detailed instructions on the rear end removal.
If weather permits i'll removing and installing the rear end tomorrow.

Also, the rear end that i'm installing have signs of recent maintenance.
The cover plate gasket sealant looks fresh, the wheel cyclinders still have dust covers, and the Hose is new.

Tony

[nbpro]

Originally Posted by tthornt

Hey all - I appreciate & thank your for the advise.
With my current setup th400 W/3:73 the truck is straining for another gear (feels like something is holding me back) and my RPM is over 2-grand.

Greg, U are the first one on the list for the rear. Perhaps we can hook up after the holidays. BTW Thanks for the detailed instructions on the rear end removal.
If weather permits i'll removing and installing the rear end tomorrow.

Also, the rear end that i'm installing have signs of recent maintenance.
The cover plate gasket sealant looks fresh, the wheel cyclinders still have dust covers, and the Hose is new.

Tony

lets hope weather permits

[Dru]

Originally Posted by LONGHAIR

That is a far more technical and expensive way to go. A simple swap of the entire housing is a much better way to go for the majority of truck owners.

If the rear end wasn't already laying around, it surely wouldn't be any more expensive, and then still retain the posi, think I seen some ring and pinions on Ebay for these rears for about $150 a set awhile back, in quite a few different ranges, but I could be mistaken. A kit to install it isn't much more.

As far as technical....a person is never too old to learn.

Simple swap....well maybe most of the time, as long as the shackle bolts co-operate, and actually come off, without a torch. And then there is the moving all the heavy stuff around. Technically its easier though.

Hope it goes well, tthornt

[LONGHAIR]

Originally Posted by 454HO

Good luck, and put me in line for that 3.73 rear if you decide to get rid of it.

Originally Posted by tthornt

Greg, U are the first one on the list for the rear. Perhaps we can hook up after the holidays.
Tony

I'm sure that you guys know better than this......454HO, you definately should as a 5 yr member.


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[LONGHAIR]

Originally Posted by Dru

As far as technical....a person is never too old to learn.

Maybe not, but it's not the easiest thing to learn in the first place. It really would benefit anyone to have an experienced person show them how. There is a bit of "art" to it as well as an investment required in some sepecial tools, that don't really do much else.....
All of that "cost" is pretty stiff for a job that most people only ever need once. It is definately worth the price to pay a professional, get the warranty, and enjoy.
Higher investment, but then again it is not an "un-known" used piece either? So, there is that too...

[nbpro]

i know i would pay a professional