4.1 CWP Diff

[geoff gibbs]

740 or 940 960 4. anything cwp /diff or complete axle Wanted
Thankyou

[Laird Scooby]

Originally Posted by geoff gibbs

740 or 940 960 4. anything cwp /diff or complete axle Wanted
Thankyou

Do you mind me asking what you'll use it for? I've got a 3.91:1 back axle that will be available sometime in the near future but it's not perfect.

[rwdkev]

Originally Posted by Laird Scooby

Do you mind me asking what you'll use it for?

I was thinking the same myself Dave. For most people, 4.1 ratio is too low for everyday use.....

[geoff gibbs]

Originally Posted by Laird Scooby

Do you mind me asking what you'll use it for? I've got a 3.91:1 back axle that will be available sometime in the near future but it's not perfect.

Hello
Thanks for asking , I will use it on my autograss car. Its a spaceframed front engine rear wheel drive car . Volvo axles are quite common in this class of racing.
Geoff

[Laird Scooby]

Originally Posted by geoff gibbs

Hello
Thanks for asking , I will use it on my autograss car. Its a spaceframed front engine rear wheel drive car . Volvo axles are quite common in this class of racing.
Geoff

I wondered if it might be something like that, the 3.91:1 axle i have is now available, it works out about 4.8% higher than what you're after and i know that can make a difference to timings but you could go slightly lower on tyre profile to return things to the same gearing overall.

For example, changing from 195/65/15 to 185/60/15 will drop the tyre diameter by 4.89% cancelling out the difference on the axle.

I don't know if there are any restrictions on tyre size for autograss but assuming wheel size isn't restricted (in diameter at least) you could keep the tyre width and aspect ratio but drop the wheel diameter.

Using the 195/65/15 as a starting point again, switching to 195/65/14 is a 3.94% drop in diameter.

https://www.etyres.co.uk/how-to-change-your-tyre-size/

That's what i used to save my brain cell number crunching at this unholy hour of the day but if that could work for you, drop me a PM and i'll give you more details of my axle.

[rwdkev]

Originally Posted by geoff gibbs

Thanks for asking , I will use it on my autograss car. Its a spaceframed front engine rear wheel drive car .

Thanks for replying and enlightening us!

Originally Posted by geoff gibbs

Volvo axles are quite common in this class of racing.

I guess that's because the Volvo 700/900 is probably the last volume car to have a live rear axle - apart from vans, pick-ups and off-roaders........?

Can you think of anything else Dave....?

[Laird Scooby]

Originally Posted by rwdkev

Thanks for replying and enlightening us!



I guess that's because the Volvo 700/900 is probably the last volume car to have a live rear axle - apart from vans, pick-ups and off-roaders........?

Can you think of anything else Dave....?

There's the Vauxhall Carlton/Omega/Senator range, got a feeling they later changed to an IRS set up but may be wrong.

There's a few others i can think of but they're all a bit older than the 7/9xx as in they were ended on or about the time the 7xx came into being. Things like the Nissan 300C estate (rare as hens teeth when new, now found next to the spare unicorn horns), Opel Manta and one or two more but there is also the Jeep Cherokee from 92-99 but the back axles for those are closely guarded because they tend to be Dana 1040/1 (in other words, the LSD version of what's in most 7/9xx) and i think that's about it.

Not sure if you'd class the Cherokee as an off-roader, perfectly capable of it but most were used as Chelsea Tractors.

[geoff gibbs]

Originally Posted by Laird Scooby

I wondered if it might be something like that, the 3.91:1 axle i have is now available, it works out about 4.8% higher than what you're after and i know that can make a difference to timings but you could go slightly lower on tyre profile to return things to the same gearing overall.

For example, changing from 195/65/15 to 185/60/15 will drop the tyre diameter by 4.89% cancelling out the difference on the axle.

I don't know if there are any restrictions on tyre size for autograss but assuming wheel size isn't restricted (in diameter at least) you could keep the tyre width and aspect ratio but drop the wheel diameter.

Using the 195/65/15 as a starting point again, switching to 195/65/14 is a 3.94% drop in diameter.

https://www.etyres.co.uk/how-to-change-your-tyre-size/

That's what i used to save my brain cell number crunching at this unholy hour of the day but if that could work for you, drop me a PM and i'll give you more details of my axle.

Thanks for the info. The reason I would like a 4.1 is to replace my worn out one. ( I didnt set it up correctly ! ) I can see what your saying re the smaller tyre sizes. Ideally I would like to go bigger , not smaller.
Will let you know on the 3.9
Thanks

[rwdkev]

Originally Posted by geoff gibbs

740 or 940 960 4. anything cwp /diff or complete axle Wanted

The most likely place to find a 4.1 diff is the 960 mk2 2.5. Ironically, these are all IRS as opposed to live axle but I'm pretty sure the crown wheel, pinion and most of the other innards are common to both types. Hopefully someone else on here will be able to confirm that.

[rwdkev]

Originally Posted by rwdkev

The most likely place to find a 4.1 diff is the 960 mk2 2.5.

This is an old thread but it might be worth getting in contact.....

https://www.volvoforums.org.uk/showthread.php?t=286082