G80 240 install

Quick question. Just pulled a G80 out of a 94' 940. I got everything G80 and pinion. I walk off without the pinion bearings. Do I need to go back and get them or will the bearings in the 240 pinion go on the G80 pinion. Help me here as the car will be going to the scrapper soon. Thanks

It depends on the 240.

The early cars had 1030 axles. The ring and pinion are smaller
and incompatible with the 1041 (G80 axle) parts.

The later (and turbo) cars had 1031 axles that take the same
size gears as a 1041.

In both cases, the G80 carrier itself will fit in the axle.

For the 1030 you will have to use the ring and pinion from the
existing axle, for the 1031 you have a choice.

It is considerably easier to swap just the carrier in any case,
if you swap the gears, they will need to be set-up properly.

In most cases, if you use the shims from the old carrier, the G80
carrier will bolt in within acceptable tolerances. It is a very
good idea to measure the backlash and check the pattern to be
sure.

The 240 axle will probably require that the passenger side
half-shaft be trimmed about a quarter inch, don't just jam it in
and bolt it up, check to see if it goes in all the way first.

Edit:
To actually answer your question, in the 1031 axle case, the
bearing will work, but it is not a bad idea to use new ones.
Don't mix and match bearings and races from different sets.
If you are going to swap gears, you should put in a new seal, at
the very least.

Good info, I'm going to use new seals for sure. Sorry I didn't mention before but I have 2 g80's and the proposed recipients are a 89' 240 wagon and my 91' wagon. As far as lash and trimming the passenger axle, is there a thread that will give good illustrated detail as to how this is done. My car is for everyday driving not drag racing so I don't think I have a need to modify this g80. I'm working on increasing HP but I'm definitely not drifting or doing any fast and furious type stuff. I thought these would be good for the occasional snows and bad weather here in NC. Thanks

Both of those 240s should have 1031 axles.

Use the gears in the cars if you are not building a racecar or
planning a T5z swap.

The G80 is awesome in the snow, it makes a big difference.

I would weld the flyweight myself, just to make the thing more
predictable, but it will be fine for snow traction unmodified.

You may need to cut some of the tone ring teeth for a non-ABS
240. It will be obvious if you need to.

I would just use the ring gear from the car it's being installed in. Leave pinion alone. Measure backlash, etc and make sure have the specs right.

Got it never thought of that before so just remove ring gear off g80 and use my original and slide it in. Makes sense. To Sim point welding the flywheel would mean it's in positive traction all the time. I mostly deal with old Chevy's and I know when there done like that they have difficultly when turning corners as you will get a chirping nose from the wheel to the inside of the corner. Would this be true for a modified g80.

wade454ss said:

...remove ring gear off g80 and use my original and slide it in(?)

Click to expand...

Yes. Might just get lucky with the backlash. Get magnetic base dial indicator. Slap some marking compound on the gears and check that they are meshing properly, then go go go!

Also make sure not too much side-to-side slop. Shouldn't be easy, or hard, to push the diff into the carrier. Light rubber mallet tap.

wade454ss said:

Got it never thought of that before so just remove ring gear off g80 and use my original and slide it in. Makes sense. To Sim point welding the flywheel would mean it's in positive traction all the time. I mostly deal with old Chevy's and I know when there done like that they have difficultly when turning corners as you will get a chirping nose from the wheel to the inside of the corner. Would this be true for a modified g80.

Click to expand...

Yeah, that's right. It's best to use the shims from the carrier
you are taking out (between the carrier bearings and the
carrier). Don't swap the shims side-to-side.

You need to pull the ring gear side bearing anyway, to remove the
oil slinger to access the ring gear bolts. Some people cut off
the slinger, but I like to keep it.

Some people swap the G80 carrier, shims, bearings and all. It can
work. I've always swapped the shims and used new bearings. In
any case, it is a really good idea to check the backlash with a
dial indicator.

As for welding the fly weight,

The G80 locks up when there is a ~100rpm difference wheel to
wheel. There is a second flyweight that swings out at about
40km/h that prevents this from happening. If you weld that weight
down, it will lock up at any speed, but only after it sees a
100rpm difference. So welding down the flyweight will not effect
parking lot turns and normal driving.

The issue with the speed limiting governor is that it makes the
diff unpredictable, you can never be totally sure if it is going
to lock, or if it will remain locked after a shift. With the
weight fixed (welded, or trimmed off), it will lock up every time
a wheel slips enough.

Volvo (Eaton) made it that way so that soccer moms wouldn't find
themselves locked up and oversteering in the snow at high speed.

There are some neat youtube videos that show how it works with
cool animations.

There are a few threads on here about the modfication and the
swap, and some good articles elsewhere about setting up a diff.

So this mod makes it a LSD. Not bad. I will start on the mod research after I finish getting my b21ft back in my 83 wagon. If you have any threads in mind that would be of particular interest to me please the more help the better. After understanding it better I think I would rather modify them before install. Thanks I'll be checking on youtube tonight as I'm a visual person and if I can see it I can do it. Thanks All

Me taking the easy way I've always just cut the oil splatter shield off with tin snips and swapped back to the original ring gear for the rear end I'm putting the g80 in and just used the bearings and races that came with the g80. So basically you just put the ring gear from your old diff on the g80 that you are putting in. That is the easiest. And you might have to cut that driver side axle if it wont' go in all the way. At some point 91 or 92? You dont' have to.

^^ABS driver side axle

wade454ss said:

So this mod makes it a LSD.

Click to expand...

No, it makes it a locker. LSD's are different.

sbabbs said:

Me taking the easy way I've always just cut the oil splatter shield off with tin snips and swapped back to the original ring gear for the rear end I'm putting the g80 in and just used the bearings and races that came with the g80. So basically you just put the ring gear from your old diff on the g80 that you are putting in. That is the easiest. And you might have to cut that driver side axle if it wont' go in all the way. At some point 91 or 92? You dont' have to.

Click to expand...

Do this. No need to fool around with the ring and pinion of you re-use the one that's in your axle.

sim said:

Yeah, that's right. It's best to use the shims from the carrier
you are taking out (between the carrier bearings and the
carrier). Don't swap the shims side-to-side.

Click to expand...

The shims on our Dana 30/31/41 are pressed between the bearing and the diff, right? It's been a while since I have been in one. I have a G80 I pulled out of a 1993 945 sitting on the shelf. I was thinking to myself, "Where the hell are the shims!? They didn't spill onto the ground when I pried the diff out..."

Research concluded shims are NOT on the outboard side of the bearing, but on the inboard side. It's different than say, a Ford 8.8.

Sure looks like it..

Oh and don't forget THIS thread. G80 locker mod. One of the articles on the main page we forget about: http://www.turbobricks.com/mods.php?content=art0027

ZVOLV said:

The shims on our Dana 30/31/41 are pressed between the bearing and the diff, right? It's been a while since I have been in one. I have a G80 I pulled out of a 1993 945 sitting on the shelf. I was thinking to myself, "Where the hell are the shims!? They didn't spill onto the ground when I pried the diff out..."

Click to expand...

sim said:

It's best to use the shims from the carrier
you are taking out (between the carrier bearings and the
carrier). Don't swap the shims side-to-side.

Click to expand...

Yep, under the bearings.

The differential in all three axles; 1030, 1031, 1041, are all
Dana 30. The 3.73 and up Dana 30 carrier in fact, regardless of
actual axle ratio.

I like to take them all apart and clean and inspect them before
putting them in. I had one open on the bench last night.

You do need a bearing puller and a shop press to replace the
bearings. I bought a cheap 20 ton press the first time I did a
G80 and it has proven to be worth the floor space it takes up.

One of the reasons I like to keep the slinger, is it will prevent
a loose ring gear bolt from backing right out and destroying
everything. Those bolts want to be torqued up carefully.

sbabbs said:

And you might have to cut that driver side axle if it wont' go in all the way.

Click to expand...

I had to trim one of the half-shafts on both an '82 and an '89,
but I was fairly sure it was the passenger side. I could be
wrong. Fit them up carefully to see. It's less than a quarter
inch that needs to come off. You can do it easily with a zip disk
on an angle grinder. Cut it slowly to avoid overheating the metal
and screwing up the temper.

If the nice weather holds, I may get mine installed in the wagon
today.

I just shade treed mine in. I didn't feel like paying a shop to do it right, and I figured if I screwed it up badly I could jsut snag another axle somewhere. Or move on up to a FoMoCo 8.8.

But I just took the alxes out a couple of inches, move the panhard rod and removed the cover. Then slipped out the old open diff carrier after I 'played' with it a bit and got a feel for how it felt. Then slapped in the G80 with it's own ring gear against the 240's original pinion gear. I played with that for a bit and it felt the same. Same amount of slack in all directions (i.e. very little, but not none). Bolted it all back together, and I've put 40k-ish miles on it. Nice and quiet, no howl, it cretainly didn't grind itself to bits right away.

I wouldn't recommend anyone else do that, though. Just that it worked well for me.

Wow, mixed and matched ring and pinion! That's ballsy.

Many people have just slapped them in with no problems.

Not everyone has had the same luck:
http://turbobricks.com/forums/showthread.php?t=281987

sim said:

Wow, mixed and matched ring and pinion! That's ballsy.

Many people have just slapped them in with no problems.

Not everyone has had the same luck:
http://turbobricks.com/forums/showthread.php?t=281987

Click to expand...

I've trusted my luck entirely with my 91 244. Slapped a g80 in along with some new oil, just re used the gears, bearings, shims etc and had no issues for probably 10k miles before I swapped the 3.73s out for 4.10s. Even then, I was on a time crunch so I just swapped the ring gear, took my pinion out and slapped the new one in on the old race. I've probably been 15k to 20k on this since I put that in and not so much as a peep.

I've been waiting patiently for it to go out so I have a good excuse to go 8.8 but I've had no luck with that.

I'm pushing a fair amount of HP through mine as well, it's not been 40K miles of easy cruising.

JohnMc said:

I'm pushing a fair amount of HP through mine as well, it's not been 40K miles of easy cruising.

Click to expand...

Yeah, it's outlasted what, three high power redblocks?

8V, pinged to death 16V, and the broken wristpin 16V.

Next up: can it survive an LS?

Although it's just fine now.