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nvandal Member
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Can anyone give me accurate information on the following concerning the five speed gearbox? - What year and model BMW was it used on? - Any model numbers on the box? - Would the BMW box fit the Jensen bell housing? - Does the BMW gearbox have the same shifter assembly as on the Jensen? Any knowledgeable help would greatly be appreciated. Most thankful, Norm Vandal Roxbury, VT |
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Judson Manning Member 
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Norm, You may want to check elsewhere on the board, I'm pretty sure we've discussed this topic in depth. For the BMW connection try: http://www.bimmers.com/02/faq/transmission.html The vast majority of BMW (Getrag) transmissions have an integral bellhousing which is specific to the BMW block and will not bolt-up to the 907. In summary, the only bolt-on options are as follows: JH 4-speed (Chrysler unit) with separate (907 specific) bellhousing JH 5-speed (Getrag 235/5 unit) with separate (907 specific) bellhousing Lotus Elite (Lotus 5-speed) with separate bellhousing. While nice on paper, it is fragile and parts are impossible to find. Lotus Eclat S2 (Getrag 265 unit used in early BMW M3s) with separate (912 specific) bellhousing. Bellhousings are ridiculously rare and the 265 ratios aren't exactly JH friendly. Lotus Excel (Toyota W58 unit used in the Supra) with separate (912 specific) bellhousing. Bellhousings are attainable, but signigicant modification is required. The Conversion Components kit is based on the Lotus Excel design. After modifying a Lotus Excel bellhousing to fit my car, I can honestly say the CC kit is well worth the money! Anything else requires significant fabrication work to develop a custom bellhousing, clutch, likage, etc. If you have the equipment, then you could theoretically adapt just about any transmission. How far does one go before the CC kit becomes the most practical solution? Judson |
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nvandal Member
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Judson, First, did you get a look at my front and rear disk conversion kits? Did Ron Earp send you photos? I tried to send them to you but didn't have your email. The transmission issue is that I've located a bunch of Getrag BMW gear boxes, of unknow variety at present. However, it's likely that there may be some that fit the bill. I'm still a bit confused by your post. You say the Getrag 935-5 unit fits the Jensen. Will it bolt to a four speed Jensen bell housing? Or, do you need a five-speed bell housing ( if there is such a thing? ) My car is currently being stored and painted. I switched from a four to a five speed using tranny and bell housing from a 75 donor car. I can't get at it right now to do my own " learnin". So, I'm not looking to switch..already done so. I'm looking to buy at least a spare gearbox for my car. Any idea what year and car the 935-5 came off? Help if you can. If you want brake kit photos email me at home off this list. vandal@tds.net Thanks, Norm V. |
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normv Member 
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There is no BMW gearbox which will bolt straight into a Jensen 5 speed bell housing or not, the BMW equivalent gearbox to the Jensen 5 speed has the bell housing cast into the case, the only close direct replacement Getrag I have found is the lotus bell housing with the Getrag 265 as Judson say’s these are very rare , this gearbox is bigger than the Jensen one. |
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nvandal Member
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Wow...what a disappointment. This guy has a whole bunch of Getrag gearboxes and not a one will fit the Jensen bellhousing? I am correct? I'm reading you posts correctly? Thanks, Norm Vandal |
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Ron Earp Member 
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That is correct as far as I know. None of the Getrag BMW boxes made match the pattern of the 235 transmission, unfortunately. I have one five speed in the car, and one as a spare. In fact, just cleaned up the spare the other day. If I didn't have to run them for racing I wouldn't - I'd use what Judson and others recommend - Toyota 5 speed or a Ford 5 speed. Much more robust, easily repaired, and affordable. You have two "easy" choices other than an adapter kit, the stock Chysler 4 speed and the stock 235 Getrag 5 speed. A lot of those transmission/combinations Judson lists are extremely rare in the US due to numbers of cars available. Ron Last edited on 11-19-2006 02:20 pm by Ron Earp |
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normv Member
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If he has one with a detachable bellhousing like the 265 it is possible to cut down the 4 speed bellhousing and weld a new face to it to adapt this gerarbox fairly easily. |
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Sylva Member
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Have a look for a Lotus Sunbeam gearbox on ebay uk, they come up every few weeks, but they are expensive (around 700 US$ for std ratio, and twice that for a GP4 set of ratios), But they come ready with a 900 series bell housing that fits a 910, a 911 or a 912, so I assume a 907, and a cable clutch. This is the getrag box as per the M3/M5, so I assume it is the same box as you are talking about, but with a special case and 900 bell housing made by the factory. These boxes take a lot of power, I've heard talk of 700+ horse power, What I know is I've gone through 3, 2.2 engines and never had any trouble with the box, either in a Rally sunbeam or on my track car. And the ratio's are ideal for a 2.2. Problem is that the box is very slow across the gates, 4-3 is very slow, but this boxis bomb proof. You would need to source a clutch plate as the spines are not as the Elite etc, I am told that there are two different spines available, but I've only seen one. Kelvin |
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Judson Manning Member
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Kelvin, Thanks for the connection to the Sunbeam, I always wondered what transmission was supplied in those cars. It looks like the Eclat S2 and Sunbeam share the same 265 box. You are absolutely correct the 265 is near bullet-proof, however, the ratios are a bit wide with a ridiculously low 1st gear. The guys at http://www.metricmechanics.com have a great history and analysis of this transmission. In my opinion, the BEST transmission would be the MetricMechanic 'ultimate' based on the 265. The ratios are much closer and the overdrive is retained. For racing there is probably nothing stronger, but for the street, it would be overkill. To answer your quesiton Norm, one could cut down a 4sp bellhousing to adapt ANY transmission. The challenges include turning the input shaft to match the JH pilot bearing and of course a custom clutch disc. The really bad news is that the tollerance for fitting any transmission is about 0.002" (hence the locating dowels), so the welding/maching job has to be extremely precise. When you add up the cost of welding and machining, plus linkage, etc., the bolt-on solutions become more cost-effective. Is there any more disappointment I can dish out for you today??? Judson |
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