E92 M3 Manual transmission bell housing replacement how to

[pitkin_g]

I need to swap my manual transmission on my E92 M3 that has a 1st gear grind. I was able to find a low mileage transmission but with a cracked bell housing. Id like to swap my original bell housing in place of a cracked one. Few questions:
1. Can this be a DIY job? If yes, can someone point to any threads or videos? I was not able to find any.
2. If not a DIY, what would be a course of action? Can transmission shop swap? If yes, what would be a ballpark charge to straight swap the bell housings?

Thank you all

[pitkin_g]

Any opinions on this? Thanks all

[bshowalter]

Pretty sure this isn't an option. The bell housing and transmission case are one piece. Your only option is to replace the transmission as a whole.

[m3s65b4.x]

Sry for OT but someone expierenced M/T leaking from bottom blind plug?

[amrazM]

the shaft is pressed into the bearing on the bell housing, you need press or press tool to push the shaft out of the bearing and thus out of the bell housing. I would suggest you take the gearbox to someone to have this done. its doable for sure, you have to remove the sealing cap from the top right of the gearbox which has the spring and pin for the shifter mechanism for the bell housing to come off.

[pitkin_g]

Originally Posted by amrazM

the shaft is pressed into the bearing on the bell housing, you need press or press tool to push the shaft out of the bearing and thus out of the bell housing. I would suggest you take the gearbox to someone to have this done. its doable for sure, you have to remove the sealing cap from the top right of the gearbox which has the spring and pin for the shifter mechanism for the bell housing to come off.

Based on RealOEM diagrams I thought there were 2 locking pins. If it were only pins, it wouldve been manageable, but the input shaft press in/out is a deal breaker really..... Ill see if I can find a good shop around to consult with and see what the price for bell housing swap will be

[ZiMMie]

Here is how to get the transmission disassemble.
its fairly easy.

https://www.kasutamu.eu/en/how-to-di...-53dz-gearbox/

i have attached a pdf in-case the site goes down.

[sergbaja5t]

Just to add another option, a competent welder, can repair a cracked bellhousing. I had this done on a track car. I do believe that transmission is still in service. It may not look as pretty, but.... Much easier and you wont upset the build of that transmission. Lust adding my 2 cents

[pitkin_g]

Thank you for providing the link. Very helpful research info. Made me realize that I did not want to tackle this as a diy.

I addition, I have contacted 2 transmission shops and noone wants to take on the bell housing swap job. One said they even tried once and failed.

Originally Posted by ZiMMie

Here is how to get the transmission disassemble.
its fairly easy.

https://www.kasutamu.eu/en/how-to-di...-53dz-gearbox/

i have attached a pdf in-case the site goes down.

[pitkin_g]

Originally Posted by sergbaja5t

Just to add another option, a competent welder, can repair a cracked bellhousing. I had this done on a track car. I do believe that transmission is still in service. It may not look as pretty, but.... Much easier and you wont upset the build of that transmission. Lust adding my 2 cents

This is exactly the route I took after some research on this topic. Ive noticed that bell housings are being welded quite often and with way more complex crack locations. Cracks in my bell housing were all in non structural areas. I have found a good fabrication shop and they have performed the welding. They have drilled the ends of each crack to prevent the further progress, V'd all groves, then welded.

I will tackle the install first week of January most likely.

Thank you all for the input

[amrazM]

those welds look like they have great penatration, should be good in the long term honestly.

[Mog-10]

Some of the spacing on the welds are way to far apart and they did not bother to fill the creater at the end of the welds, Potential for crack to propagate. You can see porosity if you zoom in. I get that it is cast. I would have washed over it with a tig and no filler to clean that up. Looks like they were dragging the cup on some of the welds . Not impressed at all.

I use to weld aluminum combat Craft boats at vigor for the dod for a few years. Full pen /X-ray.

[pitkin_g]

Welded transmission is installed. Properly filled with transmission pump activation. So far so good few hundred miles later.