Mk2 - 5 speed or overdrive???

[Bezerra]

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Hi there,

Just bought a 84 Mk2 diesel camper with a 4 speed gearbox.

Which is the best option to change the gearbox? 5 speed conversion or a 4 speed gearbox with overdrive?

Thanks

[doggypaddle]

In my opinion the MT75 5 speed is a good conversion, theyre cheap as chips and readily available, you will need to cut another hole in the floor for the gearstick, and use the MT75 crossmember. you will also need the MT75 propshaft, or what I have found easier in the past is to get a propshaft company to put a slider in the front most section of your existing prop and a flange to fit the MT75. Make sure you get a mechanical speedo drive one, and decide wether you want wide or close ratio. 1,2,3,are a bit lower on the wide ratio, which may be better with a heavy van.
The overdrive boxes are rarer and you will still need the prop and crossmember but you do get 6 gears, though I would say overdrive 3rd is pretty much the same as 4th.
overdrive is a tad higher than 5th gear. I found overdrive with a Di on my dads camper was too tall.
personally i would go for MT75, However i am putting an OD box in my MK2........just to be more original.
Its been 20 years since i last converted one, so i am sure someone will add to or correct my opinion!
the Iron case 5 speed is not a good gearbox.

[dumper]

Dog paddle comment on the o/d are spot on if you can only find the gearbox you can modify the gearbox cross member by cutting out the centre and lowering the centre part and reinforce it and have your prop shaft modified I preferred the o/d box as you could keep the power on when changing gears going up hill as 3rd o/d being 4 th gear ratio-ish of it and it saves cutting the floor and carpet.
I don’t know if there is clearance problem of a 5 speed hitting the floor panel but on the mk3 at the time when people fitted a MT75 to replace the early 5 speed box there was a lot of vans in scrapyards with it cut out .

[Bezerra]

Thank you for your reply’s. Can you please tell me how to see if a gearbox is MT75 our OD? I’m trying to find one in Portugal and I want to know if it’s the right one. Thanks.

[dumper]

The o/d box is like your 4 speed but instead of having the tail shaft with the rear mounting it has a extra unit that is much Bigger with the o/d gears in it if you have a look at yours you will tell the difference straight away and make sure you get the gear lever with the switch on the gear knob and wiring it’s a long time since I did the mk2 and the mk3 but I think the plug is already under the van to plug into also I can’t remember if we had to change the speedo cable with the mounting point being further back on the o/d unit .

[Bezerra]

Do you know the reference/code of de overdrive gearbox ?

[dumper]

No sorry m8 when I did mine and my mates it was just a matter of finding a box .

[Bezerra]

Thankd

[V184]

What engine is it ?

[Bezerra]

2.4 D

[dumper]

The o/d box I fitted in the mk2 came out of a mk3 and was onto a 2.4 York that later had a2.5 di fitted it used the same bell housing when the di was fitted I didn’t do it but I think they used the same clutch on the di flywheel .on my mk3 it had had a new clutch not to long before so it was a straight swoop of the box.this was back-in 1991.