1UZ to T56 Gearbox Adapter (6 Speed Manual)
- what does this adapter do?
- how can i obtain the file package?
- what is included in the file package?
- how can i get my parts machined?
- what machining options are there?
- what is the best material to use?
- how thick does the adapter have to be?
- do the raw holes need finishing?
- do the finished holes need countersinking?
- do i need the central locating shoulder?
- can i use spring steel dowel pins instead?
- will the input shaft align with the crank spigot?
- what spigot bearing should i use?
- what clutch release mechanism can i use?
- what flywheel/clutch is this designed to work with?
- is there anything else i need?
• what does this adapter do?
This adapter is designed to allow fitment of a Tremec T56 6sp manual gearbox to a 1UZ/2UZ/3UZ 4.0/4.3/4.7 Engine using the standard OEM ‘U1’ automatic gearbox bellhousing normally for use with the A340 seris gearbox (PN 35111-50010). though ather bellhousings are also compatible, including some from mitsubishi. It mounts between the bellhousing and the T56 gearbox and is centrally located to both ensuring optimal input shaft alignment within 0.1mm. There are TWO designs available to accommodate both the STD TR6060 version of this gearbox, as well as the newer 'Magnum' TR6060 edition.
• how can i obtain the file package?
The file package can be purchased here at v-eight.com (via paypal) at the following link:
http://www.v-eight.com/tech_forum/viewtopic.php?f=40&t=1328 (std version) and here
http://www.v-eight.com/tech_forum/viewtopic.php?f=40&t=1326 (mag version) , or alternatively through ebay as a ‘buy it now’ auction. Due to the costs involved in running the ebay listing, that price is unfortunately slightly higher
• what is included in the file package?
The file package includes a series of descriptive .dxf files that explain both the use and specific machining instructions for the parts, as well as simple .dxf files for the machinist to upload to their cutting software/hardware
• how can i get my parts machined?
Its up to you to find a machinist or fabrication facility capable of this kind of project. They will need to offer either water jet, plasma cutting, or other machining facilities capable of handling 10-12mm thick steel material with a cut of good finish quality. The equipment will need to be compatible with .dxf file formats for CNC coding of machine paths.
• what machining options are there?
This adapter can be made 2 ways: one way takes advantage of the U1 bellhousing’s 215mm central locating shoulder, and the other way ignores it.
The advantage of using the locating shoulder is that the adapter becomes axially ‘fixed’ by the shoulder so the centreline of the input shaft is unable to be assembled incorrectly, and once assembled, the adapter cannot move out of alignment at all.
If you chose to ignore the central locating shoulder, you are then dependent on the individual bolts to maintain overall axial alignment. The tolerances of this adapter are such that the amount of potential movement you could expect when relying on the bolts for axial alignment, as well as fixation, would be very very small. That said, we recommend the use of spring steel dowel pins in the bolt holes to remove any question of unexpected movement.
The only added complexity of utilizing the centrally localizing shoulder design is that an extra piece (file 'c') needs to be cut by your jet cutter, and this piece then needs to be assembled and welded into position within the main adapter. The added cost of fabricating this third piece is not great, and this is the preferred method of locating the bellhousing. The non centrally located design is slightly easier to fabricate, and with use of spring steel dowel pins, offers very similar assurance of overall axial alignment stability.
• what is the best material to use?
Any of the commonly available medium carbon steel alloys. You may also choose to fabricate it from any number of fancier chromolly steels should you have access to that material at reasonable prices, but we'd advise against using aluminum.
• how thick does the adapter have to be?
This depends entirely on which gearbox version you get your hands on. OEM versions have differing input shaft lengths, and how long the input shaft is, along with adapter thickness will determine how the input shaft engages the spigot bearing in the back of the crank. For the purpose of this FAQ we will discuss the Std GM (LS) gearbox with a 165mm input shaft length.
- On a UZ engine, for this gear box to adequately engage the spigot bearing when using a U1 bellhousing + adapter, the overall depth of the bellhousing and adapter assembly together should be 174mm. The U1 bellhousing is 154mm deep, and so the adapter needs to be 20mm. The adapter is comprised of 2 main parts 'a' and 'b'. To achieve this 20mm overall thickness we'd suggest fabricating part 'a' from 8mm steel sheet, and part 'b' from 12mm. These dimensions can obviously be altered to suit different input shaft lengths and other specific requirements.
- For a JZ engine, due to the different crank position relative to the back of the block compared to a UZ engine, the overall depth of the bellhousing and adapter assembly together should be 161mm. If using a J3 auto bellhousing for eg (the longer 138mm bellhousing compared to the much smaller J1) then the adapter should be about 22-23mm thick.
As for part 'c' the locating shoulder, this is not critical, and we would suggest a thickness of 12mm. this will then be fit inside part 'b' and offset to the bellhousing side about 4mm, producing a 4mm shoulder on that side.
• do the raw holes need finishing?
Yes. All the holes in the adapter files are undersized, and will require final finishing. Some require simple drilling for through fixation, other will require tapping. All instructions for each hole are described in the file package. Generally speaking 8.6mm holes need to be finished to M10, and 10.4mm holes need to be finished to M12. there are 2 dowel holes and these need finishing to 9.5mm.
• do the finished holes need countersinking?
No. there are no fouling holes on this adapter assembly
• do i need the central locating shoulder (part 'c')?
No, you don’t ‘need’ the central locating shoulder, however it is one very reliable way of ensuring correct and stable axial alignment of the installed adapter.
• can i use spring steel dowel pins instead?
Yes. Instead of fabricating a locating shoulder from file 'c' and welding it into the adapter, you can simply install spring steel dowel pins into the bolt holes, and let these engage and locate the bellhousing. This avoids more slightly more complex fabricating of the adapter, but requires greater attention to the final assembly of components
• will the input shaft align with the crank spigot?
Yes. This adapter locates the input shaft to within 0.1mm of true centreline, and to the correct depth to adequately engage the spigot bearing in the back of the crank
• what spigot bearing should i use?
The required spigot bearing is part number 63002-2RS. this is a 13mm wide bearing (3mm larger than stock) and we'd suggest installing it into the back of the crank the regular 10mm, leaving 3mm proud.
• what clutch release mechanism can i use?
Simply use the OEM hydraulic clutch release mechanism/slave that is normally supplied/used with the T56 gearbox.
• what flywheel/clutch is this designed to work with?
This adapter is not flywheel specific, and can be used with any commercially available, or custom designed specific use flywheels. The clutch is then specific to the flywheel, not to this adapter.
• is there anything else i need?
You will need bolts/hardware to assemble the components together. We’d recommend grade 12.9 metric socket head cap screws, in M10x1.25 and M12x1.25. Please see file 'd' for further details.