"74 transit MK1 with Volvo 2.3L turbo, diff question

[Alexandre]

Dear Members,

A couple of years ago I bought this beautiful Ford Transit Mk1. After a year of driving I decided to change it up a bit. I bought a Volvo 740 with 2.3l turbo engine. I demolished it, got the engine and the interior out, put a m90 manual gearbox behind it and scooped it in the Transit. At the moment the re-wiring is done, new gaslines are mounted and new brakelines are being fitted.
But, with around 200HP the old diff won't be any good. Also, I have the 5.8 diff mounted behind it, that'll give me an awesome 0-60mph time, but I don't really need it to do that.

So I was wondering if any of you know of the diff with lower ratios will be able to take this amount of HP, or if you have any other advice? I read about switching it for an Iveco Daily rear axle, which one do I need to look for?

I like to be able to cruise at 70-80mph (130kmph) comfortably without having to much RPM.

[conrod]

what is the top gear ratio of your gearbox?

I have a LWB van, similar to yours with a 3.8 supercharged V6, and a 4.63:1 diff ratio (the tallest available for this axle) The top gear ratio in mine (auto) is 0. 696:1, and this gives me 100kph @2700rpm, so 130kph would be 3500rpm. I have given it quite a hard time, even drag raced it once and it hasn't broken!

Show us some pictures of your engine installation please!

24899884_1737230549681920_5487792743622950372_n.jpg

[Alexandre]

Thanks for the answer Conrod! That sounds like a good option then. Did you buy a new diff insert or is it an original old axle? I saw the post of your build earlier, awesome van mate!
5th gear ratio is .80 or .70, not sure at the moment, but that would be fine then.

I'll make a separate post with pictures of the build later.

[Alexandre]

This was quite recently after the swap, alot has been done since.

[conrod]

nice work, I look forward to seeing more pics!

How is space for the pedals with that cutout? My Mk1 flat front with V8 is very tight!

My Mk2 came with the 4.63 diff, but you can swap the centre, or easier, the whole axle into yours. Let me know your top gear ratio, and I will put it into my gear ratio/speed calculator.

[Alexandre]

Very tight too haha, but I had planned to place the seats a bit back and I bought a wilwood racing pedalbox that will be installed soon. I'll let you know, thanks in advance!

[South Hem]

I’m running a 3.85:1 Ford 9inch diff inserted into the original Transit rear axle. Also using the standard 4 speed Laycock overdrive gearbox all driven by a 3.0 l Essex V6. That makes the gearing about right for my MK2 LWB.

[doc_bee]

@South Hem
did you only use the crown pinon set of the 9inch Ford axle or the complete unit incl. the diff?

I'm riding only a 2,8litre V6, but still with the 5,83 ratio of the Feuerwehr.

@conrad
Do you use a LSD for your drag race?

Thanks for your helps
Thomas

[conrod]

@South Hem
did you only use the crown pinon set of the 9inch Ford axle or the complete unit incl. the diff?

I'm riding only a 2,8litre V6, but still with the 5,83 ratio of the Feuerwehr.

@conrad
Do you use a LSD for your drag race?

Thanks for your helps
Thomas

Hi Thomas, no LSD, I tried to get one but could not find one. Am going to fit a Mk7 rear axle, 3.58 ratio. Again no LSD available for this that I can find!

[doc_bee]

Hi conrod, thanks for your answer.
I think it was you posting a photo of a transit twin wheel axle with a welded in 9inch Center. Do you know how this works with the half-shafts?

Thomas

[conrod]

Hi conrod, thanks for your answer.
I think it was you posting a photo of a transit twin wheel axle with a welded in 9inch Center. Do you know how this works with the half-shafts?

Thomas

yes that was me, a long time ago! I removed the axle shafts, and they were standard Transit, so the side gears must have been made to suit the Transit spline. Or possibly matched the nine inch ones anyway?

[doc_bee]

Did you take any photos or measurements of the axle?

If the number of splines between Transit and 9inch were the same, this would be a great opportunity for ratios and LSDs.

Thomas

[conrod]

Did you take any photos or measurements of the axle?

If the number of splines between Transit and 9inch were the same, this would be a great opportunity for ratios and LSDs.

Thomas

Yes it would be.

No measurements, although it was roughly same width as original. Only pic I could find:

141-4175_IMG.JPG

[doc_bee]

Thanks for that.

I have learned that the 9inch has 28 or 31splines. But the mk1/2 axle counts only 20splines. So I'm wondering how this fits.

Thomas

[South Hem]

Hi Thomas, I used the standard Transit half shafts. I am in the UK but the work was done in South Africa where I sent the van. I say this because I’m not sure how they actually did the work. The 9” has loads of options ratio wise and it’s a very strong unit. I’m very pleased with it and it makes a huge difference. 4:63 to 1 just isn’t high enough for a V6 with Overdrive. Fully loaded it gets about 20mpg and most important cruises very quietly after I spent about a grand on soundproofing the whole van!