Volvo diff identification
Looks like something out of a 1975-1985 244
Available ratios: 3.31:1, 3.54:1, 3.73:1, 3.90:1, 4.10:1
ramrod ahh ok, so different to a 240 then, I need to find a couple of these as it looks like they were hacked away with an oxy, also I have to find the correct disks and handbrake pads.
Also is this normal, when I hold the diff centre I can spin both axles with no load on them, but when I put load on the axles the diff centre will rotate both axles, would it be a LSD by chance?
244=240
Definitely not LSD
But, remove the cover to see for yourself
I have new rotors and pads available and pad pin kits
I can see 3.91:1
- Edited
Just count the teeth. Put a marker pen line on a tooth then turn it counting as you go.
My money is on 39 teeth, and 11 teeth on the pinion (from the 39 & 11 marking). Making it a 3.54, which is close to your estimation.
In future there is no need to remove the cover, which is clearly too late here, just lock one axle and turn the pinion until the other axle completes two revolutions while counting the pinion revolutions. i use a tab of masking tape on the pinion/uni joint and on the axle/tyre to keep track of the rotations. Seems you may have done this. I have done it many times and it can be done with the diff in the car, just pop it into neutral and lift one wheel up, it only takes a few minutes.
The backing plates can be bought new, I have some that came from Skandix I think, a few years back now.
The later diffs also had the rear wheel speed sensor for the speedo/ECU/cruise control which is located in the rear cover. This does not have it. My guess is the donor car was a mid '80s 244/240.
The far more common ratio is 3.73:1 which is found in lots of the 240s. Not sure what ratio you are after for your project. If you are after a burnout/better acceleration diff then the 3.73 is one step shorter and the 4.1:1 gears in a 740 twin cam diff bolt right into the 240 diff and are proper short! I have those gears in my 262 and it is REAL short! Sadly still not very quick though :-( The new engine coming may fix or help that.
Regarding an LSD a few options exist, I think VPW had an Eaton true track for about $500 or so. Plus the 400-500 to have it rebuilt-installed from a diff shop.
If you want the rear axle to live, it's good practice to have the axles crack tested, then if okay, get them shot peened - by a place that does aircraft-grade work, not some noddy at a speed shop - and all you have to worry about then is lunching the LSD's spider gears. Maybe they could benefit from shot peening, too, especially if you're going to drive it hard.
Major Ledfoot thanks for that, it will just be a weekender to take out to car shows and the odd cruise around, not driven hard, the Ute only has a small V8 in it
The upgrade is pretty much rebuilt calipers, good pads, new rotors, that’s pretty much the best it can be
They are pretty good as they are, loads of stopping power. New rotors, pads and fluid will see you through. Occasionally the calipers lock up, a set of rebuilt ones would be best while you are there.
if you are keen for more (scroll down lots):
https://www.240turbo.com/volvo240bigbrakes.html
my favourite is the Porsche calipers:
https://www.bneshop.com/collections/240/products/240-brembo-17z-adapters
Tiler
They’re stronger than a Banjo, weaker than a Salisbury.
There’s two versions of the Volvo diff.
The earlier type is called a 1030, and is a close copy of the Dana 30.
The later type is a 1031 and uses the same 27-spline axles and centre, but has a larger pinion and slightly larger crownwheel.
Changeover is the early 1980s. If it has an electronic speedo sender, then it is 1031 - but there are a few years of 1031s without the speedo sender.
You might find information about the number of ribs being an identifier (1030 vs 1031), but it is NOT accurate.
If you are going to give the diff a hard time, the first thing that will break is the cross pin.
If you weld the diff or fit an LSD, then the next thing to break is the axles. I have not tried Ledfoot’s shot peening solution.