Manual Tranmission Mounting Point Rust

[Sea Aych]

Hi everyone, i've found that i've got some sizeable rust rot on the passenger side mounting point for the transmission. It's number 2 in this photo. It's where the bolt goes through the tranny mounts into the "frame" of the car - Any suggestions on getting this repaired? Simple cut and weld?
You can see further back the mounting points for the auto transmission (the slit with the notch about 2/3rds the way down). For the manual point under number 2, it's basically rusted out so that the bolt can move around, causing a fair bit of vibration.
Any help appreciated!!

[Sea Aych]

Bump?
Anyone know if that bit of the unibody is just one sheet of metal and its gauge?

[berlow94]

The PO of my car cut and welded it with no problems at all.


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[Sea Aych]

The PO of my car cut and welded it with no problems at all.


Sent from my iPhone using Tapatalk

Cool cool, so it's just one layer of steel not some weird laminated business?
Thanks, that's all i needed to know!

[Sea Aych]

Bumping this again,
I got a quote from a shop that suggested getting rid of all the existing rust and sealing it off, then putting a bolt through the floor.
How does this compare in ease of doing compared to cutting and welding in a new plate like @berlow94 said 2 posts above?

[SmokeE30]

I feel it would be easier to make a bracket to extend over to the fresh section of track like where the auto bolts in or possibly further down the manual one if it's. Not too rusty.

[JGood]

^What he said. With my 6 speed swap, I had to make a trans brace that extends forward to reach the slots for the bolts. There is a lot of room there. I'd just weld a bracket on the trans mount that extends forward or backward (or both) to clean metal. You'll also want to cut out all of the rust and seal it all up so it doesn't spread.

Obviously the proper way to do it would be to replace the rusty metal, but it's a bit more involved to do it properly so it's structurally sound to hold the trans.

[Sea Aych]

I feel it would be easier to make a bracket to extend over to the fresh section of track like where the auto bolts in or possibly further down the manual one if it's. Not too rusty.

^What he said. With my 6 speed swap, I had to make a trans brace that extends forward to reach the slots for the bolts. There is a lot of room there. I'd just weld a bracket on the trans mount that extends forward or backward (or both) to clean metal. You'll also want to cut out all of the rust and seal it all up so it doesn't spread.

Obviously the proper way to do it would be to replace the rusty metal, but it's a bit more involved to do it properly so it's structurally sound to hold the trans.

You mean bolting the rusty side to the auto mounting point my welding something at a right angle to my existing brace? At that point wouldn't it make more of an open "S" shape, making it want to bend down on the right side where it would have bolted into the manual point originally?

[JGood]

No, the slot for the mounting bolt is about 6" long. Is the whole thing rusted out? If not, and there is still a usable section, you can extend the brace to that area.

[Sea Aych]

No, the slot for the mounting bolt is about 6" long. Is the whole thing rusted out? If not, and there is still a usable section, you can extend the brace to that area.

Close to the whole thing is pretty messed up. It's weird cuz it's only on that side... Do i have any other options?
I was thinking of maybe extending the brace back to the auto slot and keeping what's left of the bolt mounting on the manual slot as a backup - it holds-ish, but i can't tighten down the bolt for fear of ripping it through

[Sea Aych]

Close to the whole thing is pretty messed up. It's weird cuz it's only on that side... Do i have any other options?
I was thinking of maybe extending the brace back to the auto slot and keeping what's left of the bolt mounting on the manual slot as a backup - it holds-ish, but i can't tighten down the bolt for fear of ripping it through

Bump?
The whole 6" slot is done. Should i cut and weld or weld an extension to the trans brace so i can put a bolt into the clean slot for the auto transmission?

[JonasBarstad]

What did you end up doing? I have a similar problem on my e30, only on the drivers side.

[15Michaeljoseph]

interested to know as well


--Mike

[Mr. Tasty]

Most likely cutting and welding new material there.

[15Michaeljoseph]

Most likely cutting and welding new material there.

i mean one would guess that, but is a welded patch enough to support a tranny? I don't know.


--Mike