Fitting a Beetle gearbox in a bus

[chapp1123]

I was wondering if anyone on here has fitted a bettle gearbox to their van? If so, how much work is involved?

The reason I ask this is after seeing this thread http://forum.earlybay.com/viewtopic.php?f=4&t=29073 I noticed the ratios of the beetle box are pretty good compared to the 091 2 litre Bus box.

I have the 1600 petrol box with Kennedy adaptor currently with a VW 1.9TD AAZ lump. The extra torque is great but like many people I am struggling to find a decent box on a limited budget which allows a good cruising speed(60-70mph,without over revving).

I originally went to look for a 2 litre gearbox but im struggling to find one. This is annyoing as last year there were some but I didnt have the money

From the above thread AT and AS beetle gearboxes seem to have a 3.875 ratio. Which is better than the 2 litre gearbox? or have I missed something out?

Would the 1600 Beetle AT/AS box be the same bellhousing size as the bus 1600 gearbox?

Hope somebody gets what am on about!

[Bugsy_malone 666]

I'm going to bump this thread as its what I was thinking this morning.

After seeing someone in france is running a beetle box in a bay and wondering about tyres sizes, I wondered if a beetle gearbox would take the power of a stock 1600TD and the weight of a baywindow?
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Second Gear All The Way Baby!

Doing Thing Differently.

[chapp1123]

Im not sure about how much power they take but I was told the stock bus gearbox takes around 140-150BHP?

I gave up on converting to a beetle gearbox because of the amount of work needed to fit and it might not be strong enough for my AAZ anyway.

After some research I found out that you need a hanger kit to bolt the nose cone to the bus while making the bellhousing sit in the same place as the original bus gearbox(the beetle gearbox is shorter)

You would also need different driveshafts, seem to remember something about shorter T25 ones, but might be thinking of something else?

I think the gear selector rod had to be increased in length to match the new position of the gearbox.

In the end I got a 2 litre diff(4.57) fitted to my 1600 gearbox which has the tallest stock gear ratio(0.82). Works out at 60MPH@3000RPM

Not sure if thats what you were asking but took me ages to find all this out from different sources, so now its all in one place haha

Have you tweaked the pump on your 1600 yet btw? Thinking about doing this soon.

[Bugsy_malone 666]

I get the feeling you need T25 drive shafts from an auto or something, and its one side, think its something silly like that.

I know you use beetle CV inners and T2 outers, but I get the feeling that its something a bit odd.

I know the size difference on a bus box is a fair bit as I am planning to put a bus box into a beetle because they will handle 400bhp as opposed to the 150bhp a bug box takes.

I know there would be some modding, but shouldnt be to bad, biggest issue would be the fact I'd need an adaptor plate as I am running a T25 beelt housing in my bus.

Surprised the 2litre diff just drops straight in the box was it a T2 or T25 diff? I know there are some high range T25 diffs and I suspect its not far off, wouldnt it be nice if it was just drop in!

Only reason I have interest is I have some spare bug boxes

I havent tweaked my 1600TD yet, my biggest thing I need sort before I start modding the pump is to ensure I can get full throttle on the pump, pretty sure I cant, also an intercooler, I think this is essencial as giving it beans all the way upto santapod on the motorway (about 60-70miles of motorway) when you hit the A roads you suddenly find the engine has a fair bit less pickup because of all the warm air its inducting!
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Second Gear All The Way Baby!

Doing Thing Differently.

[chapp1123]

Yeah I cant remember exactly what it was you need to use but there was T25 driveshafts that were a bit shorter or you could change the CV joints and that made up the difference. Its been donebefore so shouldent be too hard to find out.

Not sure what you would have to do to convert the bell housing, might have to use an adaptor plate instead? to adapt the diesel to the beetle gearbox.

I was too but thats what the gearbox place said, since then I have heard of other boxes with a similar set up. Its a diff from the 2 litre bay box.

If you have bug box already then it would be worth your while. That was the main reason I didnt bother because for the price and the hassle I could get my bay box rebuilt. Although some of the beetle gearboxes work out at a lower final ratio than the 1600 Bus box.

Sorting your throttle and fitting an intercooler makes sense. I was going to fit an intercooler at first but never thought about the long stretches where the engine is working hard, like up hill, 75BHP in a bus is fine on the flat but when you come to a long hill and are not upto speed then its slow going.

Another reason a thought about tweaking the pump a bit is keeping the speed more easily on hills would mean less thrashing/struggling for the engine to do. Which hopefully means better than 30MPG. What sort of economy are you getting?

[Bugsy_malone 666]

If it is definitely a case of just swapping the diff over it would be easier to keep with my bay box as I could just drain the oil and take the CVs off, doing it in situ which would be shed loads easier than having to take out the engine, drain down the cooling system and remove all the wiring, take the box out and a million other things!

MPG wise with my bay varies to be honest, depends on the distance we drive it and how fast we go. As a general rule I cruise along at 55-60mph which with bigger tyres has brought the MPG up. To start with the MPG used to be 30-35 and then the other year we took it to Vanfest and we estimate (as we were filling it up at the showground with veg oil!) that we were doing something like 45-48mpg!

Went to Santapod recently to Bugjam and the 180mile odd round trip I get the feeling I used around 20-25 worth of diesel, very approximate figures as I havent filled it up again yet, but I know I put £20 in before I left so mid 40's would probably be about right.

I think the intercooler might be the next stage as realistically what we found was it was after being on the road for 2 hours with a nice hot turbo then coming off onto rather hilly A roads that there wasnt as much oomph as earlier in the journey, I'll admit its not brilliant at hills but you certainly notice the difference when its been thrashed down the motorway for 2 hours!

Intercooler should also help with fuel economy I have a choice of intercoolers kicking about: a 2ft square one from a volvo, which would be great (although maybe laggy due to size) as it would get rid of heat, but its where to put it? The other option which is smaller and more viable is a Renault 5 Turbo intercooler which I can probably fit in the engine bay, the advantage is it has a warm up thermostat flap in it so that the air reaching the engine gets up to decent operating temperature before making sure that a hot turbo is cooled a little.

Out of interest, I presume your running a mechanical throttle? I am wondering if you have/could take some photos of the mechanism to compare to what I have and see how I can improve my design!
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Second Gear All The Way Baby!

Doing Thing Differently.

[chapp1123]

I think you could possibly leave the engine in and remove part of the gearbox like your saying. I got my gearbox rebuilt by Bears and think they sell the 2 litre diffs new from America for about 300(I know, how much?!). You could always phone and check with them

That sounds similar to what we were getting in our bay, it all depended on how many hills there were. On the flat journeys you get about 45MPG going about 55-60MPH. On the hills it drops to about 30MPG which isnt surprising when the engine is flat out. Usually have to drop to 3rd and slow down a bit, which is annoying. We also run veg oil and never notcied much difference from diesel TBH.

What you say about having less power after its been thrashed sounds familiar, I just thought it was me getting bored driving an already slow bay

Definitely need to look into fitting an intercooler, just have the usual money/time issues ha. In the diesel tuning world the merc van intecooler seems to be popular, not sure if its because of size or cost or how well it mounts up. Not sure the Renault thermostat flap is as important on a diesel as it would be on a petrol? But dont think it would be a bad idea either. There was a chap on here that did a bay AAZ conversion and fitted an intercooler from the start, Will have a look at how he fitted his.

My throttle uses part of the cable from the golf the engine came from and joins onto the orignal cable near the back of the bus, this allows a bit of adjustment. I have alterered my accelerator pedal in the past to give more travel because I wasnt getting full throttle on my old engine. I will take some pictures and post them up but the changes were mostly an extension to the arm where the cable hooks on at the front of the bus. If that makes sense.

[13 window deluxe]

the bug box will fit in a bay and up gearing loads but will need adaption of the gearlinkage as the hockey stick is in another position the drive shafts will need 90mm inner bug cv's fitting and a spacer on the splines to take up the slack of the wider splines of 100mm bay drive shaft

I personally wouldnt bother a decent ratio bug box will be expensive as it will be wanted by the irs split and bug boys plus it will wont last long with the weight of a bay and the torque of a diesel i had a bug box in my split with a aaz had it strenghtened and played to suit aaz cost over £1000 plus a box to start with and it blew after about 4000miles

i doubt a new 091 diff is still available and it wouldnt be £300! it will be used at that and i doubt it would fit a 002 box anyway its the ring and pinion that alter the ratio

a intercooler in a rear engine vehicle is difficult to get cold air through and is better suited to front engine setups, the early bay with a intercooler fitted is andy wilsons van but its a charge cooler

the throttle arm needs the leverage ratio adjusting as the stock arm doesnt pull enough cable on the aaz pump to get full throttle if i remember correctly
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1964 rat 13 window deluxe 1Z tdi,
1975 rhd twin slider tintop (TBA)
1991 golf 2 gti with tweaked AHU tdi,

previous tdi swaps: gone but not forgotten
1979 rhd twin slider tintop bay ahu 1.9tdi
1990 T25 1Z 1.9tdi
1993 suzuki samurai with 1Z 1.9tdi

[chapp1123]

Looking at what 13 Window has said about the bug box fitting im remembering what put me off about using it!

Surely enough it was a ring and pinion, not a diff, that was fitted which up's the gearing similar to the 2 litre bay box. Looking at the invoice it does say 300 but that might have been including fitting

The charge cooler idea sounds interesting, will have a look for Andy's build thread. I remember having a look before, impressive stuff in there

I should get a chance to take some pics of my throttle this weekend. Think I adjusted the linkage length under the throttle pedal and the throttle arm under the van like 13 Window mentioned.