240 General: New (to me) 1980 Volvo 244

[Othen]

Originally Posted by Laird Scooby

It's just under the gear ratios about 5 pages in Alan. I haven't got the facility to copy from the pdf reader unless i reboot and use Windoze which takes about 2 hours to get working because it downloads a shedload of updates!

Hi again Dave,

I'm sorry to keep bothering you, but perhaps I'm being incredibly dim here. The only references to final drive rations I can find are for the BW/AW 55:



... which lists 3.54:1 and 3.73:1 as possibilities for the B21a motor

... and for the AW71:



... which lists 3.73:1 and 3.91:1 as possibilities, but nowhere does it refernce this to the B21a motor.

Neither of these talk of a 240 with a B21a motor and a 3.54 final drive; I've scoured the document but I still can't find that reference: am I just being dim?

Alan

[Othen]

Originally Posted by Laird Scooby

My apologies Alan, i was looking at the BW55 but further down, it shows the B21F engine had the AW71. This was a low compression, catalysed, USA emissions strangled spec engine that gave less power and torque than yours does (something like 93bhp) and lists the same axle ratios as i suggested.

... I've concluded I'm just being dim today Dave, I still can't find that piece - see my post (the one with the screen shots) above.

I should have gone to Specsavers!

Alan

[Othen]

I've just collected the wheels with the tyres taken off, on the whole they are okay and I think will scrub up fine.

The back of the wheels have a bit of surface corrosion:



... once I've cleaned them and rubbed all the corrosion off I was thinking of painting the backs (only) with smooth Hammerite, my thinking is that they won't show and Hammerite (brushed on) is pretty good at preventing corrosion in the future.

What do people think? Is this a good idea or should I use the Autotek primer and paint all over?

Alan

[Laird Scooby]

Originally Posted by Othen

What do people think? Is this a good idea or should I use the Autotek primer and paint all over?

Alan

Autotek Etch Primer and paint all over Alan!

I tried some Hammerite on a different wheel and then Autotek paint, it bubbled very nastily!

As for the bit about the B21F, it was a lot further down into that document.

[Othen]

Originally Posted by Laird Scooby

Autotek Etch Primer and paint all over Alan!

I tried some Hammerite on a different wheel and then Autotek paint, it bubbled very nastily!

As for the bit about the B21F, it was a lot further down into that document.

Yes, Hammerite probably isn’t the right product here.

Okay, I’ll see if I can find the bit about the B21a/AW71/3.54:1 diff combo; perhaps I’m being a bit dim.

:-)

PS. I’ll jack up a back wheel and see if I have a 3.54:1 or 3.73:1 axle in the morn, that would be a good starting point.

[Laird Scooby]

Originally Posted by Othen

Yes, Hammerite probably isn’t the right product here.

Okay, I’ll see if I can find the bit about the B21a/AW71/3.54:1 diff combo; perhaps I’m being a bit dim.

:-)

PS. I’ll jack up a back wheel and see if I have a 3.54:1 or 3.73:1 axle in the morn, that would be a good starting point.

I'd suggest the left hand rear wheel Alan and also that you chock the diagonally opposit wheel fore and aft so there's less risk of rolling off the jack.
Also your label may still be intact on the left hand end of the axle which might save you a lot of counting.

[Othen]

Originally Posted by Laird Scooby

I'd suggest the left hand rear wheel Alan and also that you chock the diagonally opposit wheel fore and aft so there's less risk of rolling off the jack.
Also your label may still be intact on the left hand end of the axle which might save you a lot of counting.

Many thanks Dave, I’ll probably have time to have a look in the morn.

Best wishes,

Alan

[Othen]

Originally Posted by Laird Scooby

I'd suggest 10 turns of the roadwheel to give you either 35.4 or 37.3 turns of the propshaft as trying to differentiate between 3 1/2 and 3 3/4 turns from one turn of the roadwheel could prove tricky!

I'd suggest the left hand rear wheel Alan and also that you chock the diagonally opposit wheel fore and aft so there's less risk of rolling off the jack.
Also your label may still be intact on the left hand end of the axle which might save you a lot of counting.

I think I'm being really dim this morn Dave, this makes no sense:

I have the left rear jacked up, gearbox in neutral and the handbrake off. Prop shaft and wheel marked with Tipex and this is what I can't understand: 10 turns of the road wheel gives me 18.75 rotations of the prop. The final drive ratio cannot possibly be 1.875:1. Surely with one wheel in the air all the drive is going to it so the diff is just working like a bevel gear drive - isn't it? Have I misunderstood something about live axles (chain drives on bikes are so much simpler!)?

Can you make any sense of this? Am I just being dim?

[360beast]

Nice to meet you and Bob the other day Alan, glad you had good trip and got very good economy for a 40 year old automatic car.

To clear a few things up it is an AW71L not an AW71 so it is a 4 speed with a hydraulic lock up that acts like a fifth gear, this kicks in at 64mph and drops the revs by a few hundred.

My 940 has a 3.73:1 axle and does 70mph on the speedo at 2400rpm in lock up.

[Laird Scooby]

Originally Posted by Othen

I think I'm being really dim this morn Dave, this makes no sense:

I have the left rear jacked up, gearbox in neutral and the handbrake off. Prop shaft and wheel marked with Tipex and this is what I can't understand: 10 turns of the road wheel gives me 18.75 rotations of the prop. The final drive ratio cannot possibly be 1.875:1. Surely with one wheel in the air all the drive is going to it so the diff is just working like a bevel gear drive - isn't it? Have I misunderstood something about live axles (chain drives on bikes are so much simpler!)?

Can you make any sense of this? Am I just being dim?

That's the 3.73:1 diff then Alan. Because of the differential action the output is halved so multiply 18.75 x 2 = 37.5, divide my 10 = 3.75:1, we know that's not a ratio from Volvo so it has to be 3.73:1 which is within the bounds of accepted error for manual measurement.

If the other wheel had been off the ground as well you would have seen it rotate in the opposite direction as you turned the left wheel, usually the left hand wheel has a direct connection to the crown wheel in the diff but seems not this time.

I reckon on that basis it'll handle the AW71 quite happily, whether it's a 71 or 71L as Luke has mentioned. The lock up doesn't alter the ratio in 4th/OD but simply uses a mechanical lock on the TC to give direct drive through the TC instead of having the "fluid flywheel" effect.