MB6 gearbox, the compact BE4/6

[Arthur 12]

https://www.opel-infos.de/technik/getriebe/mb6.html 

[SRDT 182]

20 hours ago, Tom16v said:

Ahh. That’s the box I need I think. Do you happen to know of any way of working out the code stamped on these boxes?

thanks again. 

20dm2k

The "20" in front is useless as you can see it's a gearbox but they punch it anyway.

[Tom16v 0]

That’s perfect thank you. I’ll keep my eye out for a box with that code. 

[Arthur 12]

If they weren't priced like they were made from gold, I would like to get one and check possibilities. It makes me wonder though whether it would be possible to modify a BE to have 6 gears between 2 bearings instead of 3 like BE3/6. Still lot's of effort for minor benefits though, but that hasn't stopped me before. 

 

I wonder why they went for 3 bearings with the BE3/6. For ease of design or because of the constraints. Normally the gears furthest from the bearings in your "Christmas tree" gear set gets shunt first.  I've seen lot's of ma gearboxes smashed on turbo-ed 106. It's mostly the 3rd gear that dies first. Increasing the distance  between bearings would mean less torque to be able to handle. It looks to me that the syncro unit's used's in the MB6 is where they have managed to create a lot more space to get 6 gears in  a little more space then 4  gears with the BE. 

 

Edited May 14, 2020 by Arthur

[SRDT 182]

The BE3/6 is derived from the Gr.A BE1/6, Peugeot Talbot Sport sold it as a kit to transform your existing 5 speed gearbox. It was the cheapest way to make a few 6 speed synchromesh for racing:

 

That being said other carmakers used this kind of design on production cars for years, notably VW, Honda and Fiat.

 

 

 

 

[Tom16v 0]

Do you happen to know whether any of the BE gearboxes in the 307 or 406 had the 19/63 final drive?

I can only find 206 boxes with  the correct codes on the continent And delivery is about £200. A bit steep for a used part. 
I expect that just shipping the pinion and crown wheel would be a lot cheaper, but the euro breakers don’t want to pull the boxes apart to get these out. 
Thanks again for your help 

Tom. 

[Arthur 12]

I have 20DM12 and 20DP10 here and both are 17 x 77. Both TU - be4r. Same box only under battery mount differs. I’m going to swap mine for a 3,8 FD soon at a chap who scraps loads of psa cars here in the Netherlands. I can ask him.  

Edited May 20, 2020 by Arthur

[SRDT 182]

You can find a 19/63 on a 208 but it's not the same part number for the secondary shaft so you probably need to upgrade other parts to fit it.

[SRDT 182]

I've found yet another 6 speed BE gearbox:

This one hail from Iran, long story short they are currently on their own and in need of a 6 speed gearbox that is both manual and automated.

The 5 speed BE is already locally produced but this new gearbox probably isn't a carbon copy of the MB6.

PSA reused the previous MCM tooling but the Iranians can't do that. Without direct support from PSA they can at best look at the finished product but needs to design something that can be produced there.

[Arthur 12]

O my. I guess that doesn't come up when you google. My Persian is a bit rusty. I guess if they do build their own MB6 clone, it will be another s*it ratio'd eco thing.

 

I have now put a FD of 3,8 in the 20DM12 I had lying around, but not before doing some measurements. 3/4 sycho cluster is sort of the same as 5th syscho. The sync ring, clutch carrier and teeth are also the same. One could use a 3/4 cluster to shift a custom 5/6 and put the bearing after 6th. So one could find a diesel 5th that is about 90 to 80% of your current 5th to use as a 6th. But you would need to lengthen the shafts somehow. I think this is almost impossible and you also need to fabricate an MB6 - BE3/6 like end casing with bearings 100% aligned. This would make the BE4 about 25mm longer, not the 55mm longer of the BE3/6 and would probably down rate the torque capacity. 

 

I think this is just about how they designed the MB6. Only the syncho cluster are even smaller, so they safe even more space. 

 

[SRDT 182]

Search "IKCO gearbox" or use google trad to search "new six speed gearbox" in Persian.

 

For now they are using their local BE3 bellhousing with a post 2007 BE4 gear housing that must be machined wide open. The new end case probably had the final machining for the bearings done after it was bolted.

[SRDT 182]

Still the Iranian gearbox, close yet not exactly the same:

 

The old XU is still in production and was even updated again so maybe it will last long enough to be mated to this transmission.

[Arthur 12]

Yeah. Longshot. If they do that, they might go with xu suitable ratio's. Only then I guess it could be wort while. The 3,8 FD in 20DM12 I have now suits me well.

 

62

114

180

225

269

 

Speeds now in km/hours @7500 with 195 50 15. Not jet tested but I think top speed in 4 is the same as 5 now. 

 

It's fine for me. (na tu 1.6 16v ITB @7500)

[SRDT 182]

This gearbox should be fitted to the newer cars first but in terms of emissions and fuel consumption the old XU probably need it the most.

[Arthur 12]

Bon. 

 

I just see it now. Your picture is the Iranian MB6? This basically is an BE4/6 by the looks of it. The starter is on the wrong side for XU and probably a bit different for tu also. 

 

MB

 

 

BE-tu

 

 

 

Edited December 11, 2020 by Arthur

[SRDT 182]

They have both the BE3 for the XU and the BE4 for the TU5JP4/EC5. They also use a modified BE3 for their EF7 engines:

 

As you can see on the picture the six speed bellhousing (probably a TU one) could still be machined to use a BE3 style clutch fork.

The regular BE4-TU bellhousing doesn't have this feature so maybe they plan to keep a fork on pivot for the cars that had a BE3.

[Darko_BG 0 1 Cars]

Hi guys i have 406 2.0 16v ew engine,did any one tried to put Mi16 XU gearbox on him,or is it posible to put final gear ratio from mi16 to ew10 gearbox?

[SRDT 182]

It's not that easy to mix and match BE3 and BE4 parts, with the Mi16 final drive you also need to use 3/4 and probably 5 from the Mi16 so it should be better to use the BE4 bellhousing and maybe also the gearcase with the BE3 internals.

Edited December 31, 2020 by SRDT

[petert 588]

Definitely can be done. Adrian Wuillemin put a 4:43 cwp into a GTi180 for someone. You'd have to ask him the details.

[Arthur 12]

 I have a 3.8 final drive in a BE4, but dunno whether that’s a BE3 or BE4 soured. 

[Arthur 12]

https://asbe-bokhar.com/article/news/207i-6-speed-mt/

 

The ratio's for this Iran gearbox for tu5 is not that bad. Relative short ratio 1 2 3 4 and kinda overdrive 5 and 6

 

 

Edited May 16 by Arthur

[SRDT 182]

That's like the MB6 E1 ratios with the D2 first gear: