Metal in Trans Fluid

[sapote]

I have zero experience rebuilding a trans but isn't the circled part from this screengrab a pair of syncros?

You're right!
My bad as I had never thought they put the synchro on the intermediate shaft for the 3rd and 4th, as it's a long way to reach the slider with the shift rod at the upper right corner. I label the 3 shift rods: R, 1/2 and 3/4.

So with both 3 and 4 synchro submerged, then why only the 4th sync with issue?
Btw, unless the box has only 1/4 qt of oil, filling the box a little lower doesn't make any difference for the wet 4th synchro.

I still don't think bad synchro is the root cause here.

[eacmen]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

https://www.youtube.com/watch?v=ueI6AaQFhPU

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

[oceansize]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

That video is fantastic.

[sapote]

Yes it's the best video so far for disassembling this box.
Couple errors in calling the 5/6th shift shaft as counter shaft at 17:21, and calling the 3/4th as 5/6th shift shaft at 40:39

[bigjae46]

BTW a month ago this guy did a great video with a tear down and re-seal of the 420G:

https://www.youtube.com/watch?v=ueI6AaQFhPU

Although he labeled the large shift fork going down the side of the trans to the intermediate shaft 5/6? Maybe that was just a mistake.

Nice! That looks far more orderly than my experiment disassembling a dead 420g. It went...pull the halves apart, a bunch of parts fall onto the floor and then I say "fuck me".

/experiment

lol

[Chrisyphus]

On the rebuild front, I'm curious to see what parts/solutions Partee Racing comes up with.

We appreciate the trust, but I will be quite surprised if Peter ever asks me to work on parts for the SMG. He is not a fan, and we do not do work we do not believe in as an organization. We are (in the very early stages of) working on solutions to incorporate existing DCT (and ZF) options to older chassis. We actually have a project E46 in the shop now for an 8HP conversion. It is not an M3, it's a 330Xi if I remember correctly- it belongs to a guy who also has an E39 M5 in for a comprehensive resto-mod project. It has a TVS 1650 twinscrew supercharger on it and was absolutely destroying the original transmission. The 8HP will retain all of the smoothness of the original trans (before it was trashed) and shift as fast as a DCT. We have some design work to do to adapt the shifter module to the chassis (as well as the trans, obviously), but my understanding is that our tuner/software engineer is creating (or building off of an existing) solution to integrate it with the OEM computer. This is the customer's beloved daily driver- he does not want to faff about with racecar problems, and we will provide him with an OEM+ solution.


To OP, that is almost certainly synchro material. This is an old thread, so I am sure you know by now, but she is cooked.

[George Hill]

We actually have a project E46 in the shop now for an 8HP conversion. It is not an M3, it's a 330Xi if I remember correctly- it belongs to a guy who also has an E39 M5 in for a comprehensive resto-mod project. It has a TVS 1650 twinscrew supercharger on it and was absolutely destroying the original transmission.

Glad to see y'all taking on transmission swaps. The E46 Non-M 8HP is no sweat electronically and mechanically. I'd like to see someone with some good knowledge of the MSS54 DME work with Kenneth (CANTCU) to make that 8HP solution work.

[Chrisyphus]

IIRC, Matt has a really clever solution up his sleeve to solve the issue, but honestly, that's all the way out of my depth. I am really good at making physical things that work well. When it comes to programming wafers made out of thinking sand that communicate via angry pixies (that there may or may not only be one of in the entire universe, somehow?) I get lost in the sauce lol