Help Re-Threading Transmission Mount Hole

[Rodney Nelson]

Originally Posted by Solamar

I weld and fabricate parts for a living and the above is how I would tackle this problem.

The rosette welds are key to the final strength.

Maybe IAN could expand on this, but I was not sure where he is saying to drill and weld the rosette welds?

Seems on the face, I would weld around the beveled front edge, but I need more than that as it cold be hard to get penetration because I would have to grind back down. So, where would you drill for rosette welds?

Thanks,

Rodney

[icarp]

PM sent Rodney
Ian

[yelcab1]

What is the cross sectional diameter of the boss where the hole is? Drill it to that size. Find or machine a solid bar to fit that hole, weld it in from the back and the front. Flatten the front, drill, retap for 12mm bolt, and you are done

[Rodney Nelson]

Ok so after reading everyone's ideas, and thank you by the way to everyone that offered suggestions.

I decided to purchase a female 12MM coupler, with an OD of 20mm. I will then drill out the hole to 20 mm, insert the coupler. I will bevel the edge of the coupler so when it sits flush at the face I will have a nice grove to weld at the front.

In the back I'm pretty sure that the drill will remove some of the bracket in the back, if not I will drill holes and then rosette weld the back to lock it in further.

This should be a very straight forward fix... famous last words.

Here are my tools for the fix....

[john walker's workshop]

Might want to use two or three smaller bits as you work up to the big one. Less shudder. Maybe.
That piece is stainless ya know. May have a weld issue, although I've mig welded SS exhaust parts , slowly, one spot weld at a time.....

[Rodney Nelson]

Originally Posted by john walker's workshop

Might want to use two or three smaller bits as you work up to the big one. Less shudder. Maybe.
That piece is stainless ya know. May have a weld issue, although I've mig welded SS exhaust parts , slowly, one spot weld at a time.....

Thank you for the advice John. I will try to step it up with some other drill bits I have.

I also did some research on the SS welding to mild steel. It seems that it can be done and it is recommended to use SS wire in the MIG, which I have. We will see how it goes. It did spend hours trying to find a round mild steel female 12 mm coupler, it does not exist on the planet. Only Hex shaped ones, and I don't have a lathe.

[Rodney Nelson]

Alright, here is what happened this morning...

I got my drill bits ready to step up to the 20mm size...



Cutting Oil...



Drill and marked off depth...



Here is the hole ready for coupler, it did punch through the back. I still need to clean up the back side and front before final fitment.



Fit is good side to side, will need to cut to length...

[Rodney Nelson]

Decided to hand cut this one...



Then I put in grooves on the front edges so I can weld it in...



Fit is good and flush at front...



Back area is all cleaned up ready for weld...

[Rodney Nelson]

Here is the weld at the back. It is SS Mig Wire as that is what is recommended when welding SS to mild steel. It does have good penetration and I decided to build it up to mimic the previous dome shape that was there before. So, don't be judging this weld. Plus, it was not too easy to get back behind this bracket.



Front was a bit lumpy too, this is really only the second time I have welded SS. By the looks of it I could have increased the power a bit and slowed the speed of the wire down a bit, but it will just get ground down anyway...



All cleaned up with a file... Looks great!



Perfect clean fit...



Thankful I'm doing this on a rotisserie and not with car in driving shape on jack stands upside down!

Thank you everyone for your suggestions.

[Solamar]

Looks great! Clean all the cutting fluid and undercoat from the area and weld it up.

Fwiw, I wouldn't bother using SS filler and the proper tri-mix. If your comfortable welding with your steel filler and argon/co2 mix use that.

[brcorp]

Perfect!!

[Solamar]

Hah, we posted at the same time...

Looks like it turned out great!

[Rodney Nelson]

Originally Posted by Solamar

Hah, we posted at the same time...

Looks like it turned out great!

Ha! I know I probably should have just used my standard MIG wire. But I have this brand new roll of SS, so this will probably be the last time I get to use it.

[Mahler9th]

Nice work.

[911obgyn]

Perfect, stronger than new, how’s the other side?

[HaroldMHedge]

Great job.

[OSC911]

Wow - awesome result. You must be happy with that.

[jpnovak]

Very Nicely done!

[icarp]

Well done Rodney
That is the same result as my suggestion .
Ian

[Rodney Nelson]

Originally Posted by icarp

Well done Rodney
That is the same result as my suggestion .
Ian

Yes! Thanks Ian!! Much easier than cutting out the bracket.