Your main problem is going to be the location of the shifter tail. I would think...you would have to go over the rear trailing member. This will mean some sheet metal removal. It will also need some creative linkage thinking.
The actual 411/412 shifter is as good as any other. In fact there is no real difference in teh 411/412 shifter and thsoe in teh bugs and type 3. The difference is in the linkage.
Due to the need to have no weight bearing on any part of tranny other than the crossmember at the case parting line on either the stock 4 speed or teh automatic....the 41/412 has the floating coupler unit at the gearbox to linkage connection. That is the whole problem with the 411/412 shifting. You must bear this in mind. alignment of the gearbox and powertrain package when using any stock 411/412 tranmission...either manula or automatic.....is crucial. If......for instance....the rear tailcone bushing is shot...and you are but a few millimeters low or high in tailshaft position......the "ball joint" in the floating coupler will shift upward or downward. When it does that......it increases the "ARC" of the rotation of teh shift rod. This causes binding or roughness when moving from lower to higher gears.
If the longitudinal postion of the drivetrain package is out either fore or aft....it increases or decreases the stroke length of teh shift rod. This moves the sliders short or long on their intended positions on the synchro hubs. This can cause popping out of gear and extended wear to the hubs.
In short...its not the shifter....but the linkage. There are some simple ways to fix this permanently...but in order to do this...you must have the bushings and adjustments of the drivetrain package worked out.
The only problem I see using an 091...is that (a) it is heavier (b) the tail cone issue...which is fixable with some fabrication (c) the gear ratios.
The gear ratios of the type 4 4 speed were superb for the powerband and weight ratio of this car. This is primarily due to the high final drive ratio. Since you cannot get that for the 091.....you will have to look to manipulating the lower gears and 4th gears to get the driving characteristics you need. Because of teh final drives in teh type 4...they were perhaps the quickest off the line of any ACVW.....that and the torque of the type 4 engine. Also it is very easy to make a spacer for the type 4 shifter (or any other) to get as much as a 50% shorter shifter throw. Ray
Its not just about top end....though those are close. If this is the one you are racing...take a look also at the 2nd and 3rd gear ratios. The rpm to mph ratios in each gear and the drop off between gears is important to how teh car drives when it is in the desired rpm/torque band of the engine. It may actually be decent. I have not checked the 091 against the 412. But remember the bus tranny was made with adifferent rpm band in mind. Ray
I haven´t got good information about the 4th gear ratio... I just visite a website that said 091 6 rip tranny has 0.89 4th gear. If that´s true this is not right choice for me...
I can easily fint T3 transmission data, but T2 is harder to find.
EDIT: yes it seems that the 4th gear is 0.889, so...
Yep...as Bruce2 and Marc explained to me some time back on the transaxle forum.....youcan have a box with a low final drive like the bus...and if the other gears are of the right ratio....you can come awfully close to the same output per rpm. I agree. But something to bear in mind. The reason why lower gears are used in heavy vehicles liek the bus and higher gears used in lighter cars like ours is the torque multiplying potential that lower gear ratios (bus) have. I'm not sure....trying to wrap my head around it...wether that same potential changes the amount of torque needed as input...to achieve the same affect in output....even if the input/output rpms are the same. Does my concern make sense? Its hard to get a grip on and I may not be correct.
But the nice thing is that there are good many gear ratios available for the 091 box. You could probably mix and match and get what you want.
But do not totally write of the 412 box. It is actually very light and very dependable. If you get into rebuilding it...I have some techniques and parts changes that can greatly help the longecvity and smoothness. It still may not be the box you want to race with just because if you detsroy it....parts are not forthcoming. Ray
I have a little bad emotion of vision that I´ll destroy these rare 412 manual gearboxes. I´d rather give these to someone who needs spare parts to remain original 412 as it is.
It has been discussed rarely in this forum about the use of 094 gearbox (vanagon wbx) in aircooled VW. Do you know why?
I think I have to ask the differences of 094 and 091 gearboxes in transaxle forum.
func412 wrote: It has been discussed rarely in this forum about the use of 094 gearbox (vanagon wbx) in aircooled VW. Do you know why?
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Side shift mechnisms in the Vanagon?
BTW, the diff ratio in the late 412 trannies was something like 3.78 with a 1:1 fouth IIRC
BTW2 I like Ray's suggestion how to prevent sticking of gears and also to shorten the trow.. hmmmm
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi www.apfelbeck.nl "Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
I have three trans in my carage. I´ll open the bottom all and see what´s inside. But if I happen to have trans with different final drive, how I can find the differences. You see... this is my first time...looking inside the transmission...really.
The only real way to find out is to disassemble the box all teh way to teh differential and either count the teeth on the ring gear or to look for the engraved size on teh ring gear.
I say that this is the only diffinitive way...because its kinda sketchy as to exactly what and when they put various gearboxes in.
Yes, teh haynes manual has pretty decent info as to what years got what...but its hard from the codes to find out what you have and also its hard to know if its the original box that came in the car you have.
It kind of looked like the early 411 sedans got the 3.73...and teh wagons got the 3.91. But that was teh earlyt pattern with teh 19mm slave. Then it appeared for a while that they all got 3.91...and they they broke it down to offer both again.
Externally...the early 19mm boxes are very different looking at the bell housing end. There was also a change to the synchros on 1/2 in like...71. That means that almost everything is the same over here.
If you have the time...it really is worth it to tear down what you have. If not just for learning.....for to inspect and see at what phase of wear your transmission is. There are some serious issues that all high milage type 4 boxes suffer from. But if you catch them early.....all is fixable.
Bear in mind. There is little that you will be able to find the parts to replace. But what you can replace is very important.
You will be able to replace the 20mm needle bearings on the countershaft. Its worthwhile to replace the shaft as well. That will be easy to make and set you back very little at any machine shop. You will be able to replace the final drive seals. o-rings and main bearings.
Unless you live near someone that has access to very odd needle bearings...that will be all that you find to replace. There are things that can be done to lots of other things. You can make the countershaft shims new for very cheap. The main needle bearings should be in very good hsape unless the yare rusted. There are some mods you can do elsewhere.
If you are not in a hurry.....tear down a box.....and I can walk you through it. Ray
OK.....some ground rules that are not in any manuals. If you are mainly just inspecting to find gear ratios....you can disassemble down to taking the transfer case off...that part with the black pan on it. From tehre....you can inspect the ring gear.
But...if you open the gear box...it really is worthwhile to replace the differential and pinion bearings. Since baseline adjustment specs generally do not exist.....you must know what the specs are that you have now.
This is jumping the gun a little....but it helps to be armed in advance.
Since the differential layout of is of the true hypoid design...its very very difficulty to get measureing equipment into the final drive housing to get a measurement of the pinion gear placement in reference to its bellhousing end bearing and teh ring gear.
If your box was running quietly...meaning no heel or toe whining....then lets assume that teh ring and pinion are in good basic adjustment..
From there...you need to measure a couple of things.
Once the transfer housing is removed....
(1) using a standard dial indicator and clamp assembly...measure the backlash on the ring gear. Lock the pinion shaft with a soft rag and a C-clamp first. By rocking the pinion......see the back-lash at the dial gauge. Check the Bentley type 3 manual for this. Its the same method for all trannys. If it is out of spec.....adjust it first. If its not correct ...its generally a couple thousandths loose.
In this situation.....out of the vehicle......you can assume to take exactly 50% of the needed gap...from each side adjuster ring....just so nothing is too tight or loose. Punch mark each adjuster ring on each side to the case. Adjust just a hair....until backlash is correct (use the same backlash specs as the type 3 automatic from the Bentley manual....it is the same differential). Remark the new adjusted position with a scratch mark on the adjuster rings.
(2) Make a mark on the differential housing (the part attached to the ring gear). One that you will not forget or confuse. Pick a flat spot...or make one on that housing. Using a very accurate caliper ...or snap gauges...measure the distance from the differential housing to the differential case. Record that.
(3) You now have enough information to at least re-assembled to the same spec that it was. This is because the depth of the pinion to ring mesh is set by the side adjusters....and measured as back-lash. Even if you change teh differential side bearings....this backlash setting will remain teh same. The only thing that will need to be re-calculated is teh bearing pre-load on the new bearings. We will talk about that when you get there. The pinion location fore and aft.....is set.....and quite nicely on this transmission type.....by a shim under the nosecone tube inside the bell housing. There is only one thing that can and will change that shim thickness. A new pinion shaft end bearing and race.
In order to make sure that the pinion gear location shim thickness must not change......before you remove the pinion shaft or the pinion gear end bearing cover inside of the bellhousing.....you need to get a long caliper or a depth micrometer with extension rods and measure from teh very end of the pinion shaft gear stack to the edge of the differential casing. Record that. Then once you change the pinioin bearings and pre-assemble...you will see if the height of the pinion shaft with refernce to teh final drive housing edge has grown or shrunk. If it has...a new a shim with the difference must be installed. More on this later. Ray
Why don't you look into the Porsche 901/915 transaxle? With some fabrication, they appear to be an ideal option. AFAIK, the nose cone places the hockey stick in roughly the same location (down low) as the original 4-speed. The 901/915 has a larger selection of parts (albeit at Porsche prices) and is well suited for racing and spirited driving.
A good suggestion. I have always wondered if that would work. I think someone just a while back posted a bit that noted they have one of each (412 and 901/915)....and said this is a bit hairier than it looks. But...with some fabrication...why not? Especially for racing. Ray
